Tuning a DT 250 2 cycle Mikuni carburetor

[graybeard via MotorcycleKB.com]

Now that the engine starts, I need to get it running right.

The Yamaha DT 250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.

Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets. Techniques?

Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?

Thanks,
Dave

[The Older Gentleman]

Post by graybeard via MotorcycleKB.com
Now that the engine starts, I need to get it running right.
The Yamaha DT 250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.
Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets. Techniques?
Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?

This is where you spend a few bucks on a secondhand manual, to find the
correct settings.

[SC Tom]

Post by graybeard via MotorcycleKB.com
Now that the engine starts, I need to get it running right.
The Yamaha DT 250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.
Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets. Techniques?
Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?
Thanks,
Dave
--
Message posted via http://www.motorcyclekb.com

You are not really going to get the expert help you need here. These guys
mean well however most don't have a clue on how these old Yamaha Enduros
work.

For the best help, join us over at www.yamahaenduro.com

Tom

[The Older Gentleman]

Post by SC Tom
You are not really going to get the expert help you need here. These guys
mean well however most don't have a clue on how these old Yamaha Enduros
work.

You man, like this old guy who recommended checking the spark plug first
and the coil/HT lead second, and who scored a bullseye?

[SC Tom]

Post by The Older Gentleman

Post by SC Tom
You are not really going to get the expert help you need here. These guys
mean well however most don't have a clue on how these old Yamaha Enduros
work.

You man, like this old guy who recommended checking the spark plug first
and the coil/HT lead second, and who scored a bullseye?
--
BMW K1100LT Ducati 750SS Honda CB400F, SL125 & SH50
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5 The bells, the bells.....
chateau dot murray at idnet dot com

Who is "You man"?

I see you still think your the knowledge base of all things motorcycles.

If the person posting really wants to get his bike running right and learn
how to do it with the least amount of mistakes, he should ask those who work
on these bikes every day.

Also please keep the name calling to a minimum, there are children visiting
here.

Tom

[The Older Gentleman]

Post by SC Tom

Post by The Older Gentleman

Post by SC Tom
You are not really going to get the expert help you need here. These guys
mean well however most don't have a clue on how these old Yamaha Enduros
work.

You man, like this old guy who recommended checking the spark plug first
and the coil/HT lead second, and who scored a bullseye?
--
BMW K1100LT Ducati 750SS Honda CB400F, SL125 & SH50
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5 The bells, the bells.....
chateau dot murray at idnet dot com

See this above? It's a sig. Try to snip it.

Post by SC Tom
Who is "You man"?

Sorry? I don't understand this.

Post by SC Tom
I see you still think your the knowledge base of all things motorcycles.

That'll be 'you're'. And, no, I don't, but I do have quite a lot of
experience. And as has been pointed out, a two-stroke single is the
simplest engine there is, so if it stops running, there are only so many
things to check.

Post by SC Tom
If the person posting really wants to get his bike running right and learn
how to do it with the least amount of mistakes, he should ask those who work
on these bikes every day.

Not every day, but certainly every week.

Post by SC Tom
Also please keep the name calling to a minimum, there are children visiting
here.

What names are you referring to? I don't see any name-calling in what
you've quoted above.

My advice to you is to come off the high horse, and stop acting like a
prat. In the nicest possibly way.

[SC Tom]

Post by The Older Gentleman

Post by SC Tom

Post by The Older Gentleman

Post by SC Tom
You are not really going to get the expert help you need here. These guys
mean well however most don't have a clue on how these old Yamaha Enduros
work.

You man, like this old guy who recommended checking the spark plug first
and the coil/HT lead second, and who scored a bullseye?
--
BMW K1100LT Ducati 750SS Honda CB400F, SL125 & SH50
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5 The bells, the bells.....
chateau dot murray at idnet dot com

See this above? It's a sig. Try to snip it.

Post by SC Tom
Who is "You man"?

Sorry? I don't understand this.

Post by SC Tom
I see you still think your the knowledge base of all things motorcycles.

That'll be 'you're'. And, no, I don't, but I do have quite a lot of
experience. And as has been pointed out, a two-stroke single is the
simplest engine there is, so if it stops running, there are only so many
things to check.

Post by SC Tom
If the person posting really wants to get his bike running right and learn
how to do it with the least amount of mistakes, he should ask those who work
on these bikes every day.

Not every day, but certainly every week.

Post by SC Tom
Also please keep the name calling to a minimum, there are children visiting
here.

What names are you referring to? I don't see any name-calling in what
you've quoted above.
My advice to you is to come off the high horse, and stop acting like a
prat. In the nicest possibly way.
--
BMW K1100LT Ducati 750SS Honda CB400F, SL125 & SH50
chateau dot murray at idnet dot com
"What you're proposing to do will involve a lot of time
and hassle for no tangible benefit."

How low will you go? Calling the spell check gods to back your position
means you have no valid point to make. As for keeping the name calling down,
it appears you just could not resist one last swipe.

BTW, read your first reply because I still would like to know who "You man"
is referring to (these are your own words).

Have a nice day!

Tom

[TOG@Toil]

Post by SC Tom

Post by The Older Gentleman

Post by SC Tom

Post by The Older Gentleman

Post by SC Tom
You are not really going to get the expert help you need here. These guys
mean well however most don't have a clue on how these old Yamaha Enduros
work.

You man, like this old guy who recommended checking the spark plug first
and the coil/HT lead second, and who scored a bullseye?
--
BMW K1100LT  Ducati 750SS  Honda CB400F, SL125 & SH50
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5  The bells, the bells.....
chateau dot murray at idnet dot com

See this above? It's a sig. Try to snip it.

Post by SC Tom
Who is "You man"?

Sorry? I don't understand this.

Post by SC Tom
I see you still think your the knowledge base of all things motorcycles.

That'll be 'you're'. And, no, I don't, but I do have quite a lot of
experience. And as has been pointed out, a two-stroke single is the
simplest engine there is, so if it stops running, there are only so many
things to check.

Post by SC Tom
If the person posting really wants to get his bike running right and learn
how to do it with the least amount of mistakes, he should ask those who work
on these bikes every day.

Not every day, but certainly every week.

Post by SC Tom
Also please keep the name calling to a minimum, there are children visiting
here.

What names are you referring to? I don't see any name-calling in what
you've quoted above.
My advice to you is to come off the high horse, and stop acting like a
prat. In the nicest possibly way.
--
BMW K1100LT  Ducati 750SS  Honda CB400F, SL125 & SH50
chateau dot murray at idnet dot com
"What you're proposing to do will involve a lot of time
and hassle for no tangible benefit."

How low will you go? Calling the spell check gods to back your position
means you have no valid point to make. As for keeping the name calling down,
it appears you just could not resist one last swipe.
BTW, read your first reply because I still would like to know who "You man"
is referring to (these are your own words).

Ah. Mea maxima culpa. 'You mean'.

I still don't understand what the name calling is, though. Who have I
called what, exactly? Take your time.

[IdaSpode]

On Tue, 25 Mar 2008 07:58:16 -0700 (PDT), "***@Toil"
<***@yahoo.co.uk> wrote:

<snip>

Post by The Older Gentleman
You man, like this old guy who recommended checking the spark plug first
and the coil/HT lead second, and who scored a bullseye?

I suppose if you consider hitting the broad side of a barn from 10'
away with a shotgun "scoring a bullseye", then that you did. Not quite
rocket science when a 2S has no spark.

You need to raise your standards...

<snip>

DJ

[TOG@Toil]

Post by IdaSpode
<snip>

Post by The Older Gentleman
You man, like this old guy who recommended checking the spark plug first
and the coil/HT lead second, and who scored a bullseye?

I suppose if you consider hitting the broad side of a barn from 10'
away with a shotgun "scoring a bullseye", then that you did. Not quite
rocket science when a 2S has no spark.
You need to raise your standards...

I quite agree. Nobody said it was difficult. Like Mark Olson, I'm
constantly amazed at the way people will suggest the most abstruse and
difficult solutions to problems, when the simplest is usually correct.

I mean, there we had people discussing the points and the magneto.
Check the plug, plug cap, HT lead, coil and wiring connections, in
that order. And after those, then you can start looking deeper into
the engine.

As for this one, could be a few things. Bunged up carb is most likely.
Could conceivably be leaking crank seals, and oil deposits on the plug
are being mistaken for soot. But I'd bet on the carb first.

And I still think my original suggestion is valid. Get a bloody manual
and check the settings. I've lost count of the number of posters who
come to this ng asking for the most basic service data or, worse,
asking where they can d/l a freebie manual. JUST BUY THE FUCKING THING!

[oldgeezer]

Post by SC Tom
You are not really going to get the expert help you need here. These guys
mean well however most don't have a clue on how these old Yamaha Enduros
work.
For the best help, join us over atwww.yamahaenduro.com
Tom

Right. These things only look vaguely like a motorcycle, but they are
something totally different.

I heard there is a thing they call 'spark' inside these miracle
things. But I haven't got a clue what that would be.

As for T.O.G. he only scored a lucky hit with his advise
to check the coil.

Rob.

[The Older Gentleman]

Post by oldgeezer
As for T.O.G. he only scored a lucky hit with his advise
to check the coil.

He didn't, actually. He gave good advice for the problem. Start with the
simplest things, and check them. Spark plug first, coil and HT lead
second, wiring connections third.

Experience born of decades of fiddling with old bikes.

Of course, if it makes you feel better to believe it was a lucky guess,
don't let me shatter your illusions.

[oldgeezer]

Post by The Older Gentleman

Post by oldgeezer
As for T.O.G. he only scored a lucky hit with his advise
to check the coil.

He didn't, actually. He gave good advice for the problem. Start with the
simplest things, and check them. Spark plug first, coil and HT lead
second, wiring connections third.
Experience born of decades of fiddling with old bikes.
Of course, if it makes you feel better to believe it was a lucky guess,
don't let me shatter your illusions.

Read between the lines T.O.G.
Someone writes that you and I and others have no idea
about the mysteries that combine to get a 2-stroke bike going.

And you gave the obvious things to check first.

To give it straight; A 2-stroke single cylinder air-cooled, is about
the simplest machine there is.
Anybody writing that you need to be a guru to understand
how they work, hasn't got a clue himself on how they work.

I mean: How dumb must you be to figure that a missing spark might
be caused by points, condenser, cabling, coil, or spark plug?

Of course you were right. And Yes: it was not a lucky shot.

Rob.

[The Older Gentleman]

Post by oldgeezer
Read between the lines T.O.G.

Ah. Sarcasm. I missed it. My bad.

[SC Tom]

Post by oldgeezer

Post by The Older Gentleman

Post by oldgeezer
As for T.O.G. he only scored a lucky hit with his advise
to check the coil.

He didn't, actually. He gave good advice for the problem. Start with the
simplest things, and check them. Spark plug first, coil and HT lead
second, wiring connections third.
Experience born of decades of fiddling with old bikes.
Of course, if it makes you feel better to believe it was a lucky guess,
don't let me shatter your illusions.

Read between the lines T.O.G.
Someone writes that you and I and others have no idea
about the mysteries that combine to get a 2-stroke bike going.
And you gave the obvious things to check first.
To give it straight; A 2-stroke single cylinder air-cooled, is about
the simplest machine there is.
Anybody writing that you need to be a guru to understand
how they work, hasn't got a clue himself on how they work.
I mean: How dumb must you be to figure that a missing spark might
be caused by points, condenser, cabling, coil, or spark plug?
Of course you were right. And Yes: it was not a lucky shot.
Rob.

Name calling is sure sign of low intelligence.

This part of the thread is about carb settings or had you not noticed?

That being the case, have you considered after the lack of spark problem and
the start up of a carb problem the poster might need to check and replace
the main seals?

Tom

[The Older Gentleman]

Post by SC Tom
Name calling is sure sign of low intelligence.

Wrong.

Getting your attributions wrong in a simple thread might be, though.

[SC Tom]

Post by The Older Gentleman

Post by SC Tom
Name calling is sure sign of low intelligence.

Wrong.
Getting your attributions wrong in a simple thread might be, though.
--
BMW K1100LT Ducati 750SS Honda CB400F, SL125 & SH50
chateau dot murray at idnet dot com
"What you're proposing to do will involve a lot of time
and hassle for no tangible benefit."

Why do some people need to cut and paste replies? What are you afraid of?

Again, have a nice day!

[TOG@Toil]

Post by SC Tom

Post by The Older Gentleman

Post by SC Tom
Name calling is sure sign of low intelligence.

Wrong.
Getting your attributions wrong in a simple thread might be, though.
--
BMW K1100LT  Ducati 750SS  Honda CB400F, SL125 & SH50
chateau dot murray at idnet dot com
"What you're proposing to do will involve a lot of time
and hassle for no tangible benefit."

Why do some people need to cut and paste replies? What are you afraid of?

ITYF that what you are referring to is known on Usenet as a "sig".

Short for 'signature'.

Most people snip it in their replies.

<Buzz Lightyear>
You are a sad, strange little man and you have my pity.
</BL>

[Rick Cortese]

Post by SC Tom

Post by graybeard via MotorcycleKB.com
Now that the engine starts, I need to get it running right.
The Yamaha DT 250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.
Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets. Techniques?
Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?
Thanks,
Dave
--
Message posted via http://www.motorcyclekb.com

You are not really going to get the expert help you need here. These
guys mean well however most don't have a clue on how these old Yamaha
Enduros work.
For the best help, join us over at www.yamahaenduro.com
Tom

Another lying idiot trying to snipe off members from established forums
to go to a 7¢ a click advertisizing site.

I understand people like stock brokers will give bad advice to make
millions but I can't see why someone would do it to pick up an extra 14¢
for someone who posts a question then returns to find out it isn't
answered. There are whores and there are cheap whores.

You know if this was a web site you were pulling this crap in, the owner
would delete your post and ban you from the site.

Rick

[TOG@Toil]

Post by Rick Cortese
Another lying idiot trying to snipe off members from established forums
to go to a 7¢ a click advertisizing site.

Heh. I must be innocent. I never thought of that.

[SC Tom]

Post by SC Tom

Post by graybeard via MotorcycleKB.com
Now that the engine starts, I need to get it running right.
The Yamaha DT 250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.
Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets. Techniques?
Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?
Thanks,
Dave
--
Message posted via http://www.motorcyclekb.com

You are not really going to get the expert help you need here. These guys
mean well however most don't have a clue on how these old Yamaha Enduros
work.
For the best help, join us over at www.yamahaenduro.com
Tom

Another lying idiot trying to snipe off members from established forums to
go to a 7¢ a click advertisizing site.
I understand people like stock brokers will give bad advice to make
millions but I can't see why someone would do it to pick up an extra 14¢
for someone who posts a question then returns to find out it isn't
answered. There are whores and there are cheap whores.
You know if this was a web site you were pulling this crap in, the owner
would delete your post and ban you from the site.
Rick

Have you even visited the site?

I suspect you have the same low opinion of he GS Resources and Honda SOHC
forums too.

Using the terms sniping and established forums implies you might be
restraint to the ever changing internet experience.

Tom

[Rick Cortese]

SC Tom wrote:
<snip>

Post by SC Tom
Have you even visited the site?

Yes, it is the reason I decided you were a weasel.

Post by SC Tom
I suspect you have the same low opinion of he GS Resources and Honda
SOHC forums too.

You started off insulting everyone here. For all you know people that
post here are also members of that forum. I belong to a Honda XL and a
Honda Elsinore and unless a question that specifically requires
information like serial number vs. model year, I don't advise people
that nobody knows what they are doing here and to go to one of those boards.

In addition to my XL and Elsinores<plural> I own a 1974 DT360<electronic
ignition in that one> and a DT100. I have a MX125 that I am currently
restoring. I imagine most other members in this newsgroup have similar
stables or histories of owning bikes.

The reason I didn't throw my hat into the ring with an answer was I
thought the answers alread given were excellent and covered the likely
problems.

Post by SC Tom
Using the terms sniping and established forums implies you might be
restraint to the ever changing internet experience.

I stand by my statement. If you had posted that in a moderated forum or
on a web based board, it would have been deleted and you would be
banned. It was and is inappropriate.

Rick

[TOG@Toil]

Post by Rick Cortese
You started off insulting everyone here.

And lying. Let's not forget lying.

[SC Tom]

Post by ***@Toil

Post by Rick Cortese
You started off insulting everyone here.

And lying. Let's not forget lying.

Like you suggested to another poster in another thread here on RMT, you need
to grow a thicker skin if you feelings were hurt from any of my comments.

Tom

"Ever wonder why there is so much trouble in places like the middle east and
Asia? Blame the greed of the English and the French." T. Krobling, 1948

[The Older Gentleman]

Post by SC Tom

Post by ***@Toil
And lying. Let's not forget lying.

Like you suggested to another poster in another thread here on RMT,

I don't think that was me.

Post by SC Tom
you need
to grow a thicker skin if you feelings were hurt from any of my comments.

I never said they were. I encounter liars on a daily basis and they
don't hurt me; not one whit.

Actually, considering the above, you may not be a habitual liar: just
unable to work out who said what, so you attribute A's remark to B and
have done with it.

[SC Tom]

Post by The Older Gentleman

Post by SC Tom

Post by ***@Toil
And lying. Let's not forget lying.

Like you suggested to another poster in another thread here on RMT,

I don't think that was me.

Post by SC Tom
you need
to grow a thicker skin if you feelings were hurt from any of my comments.

I never said they were. I encounter liars on a daily basis and they
don't hurt me; not one whit.
Actually, considering the above, you may not be a habitual liar: just
unable to work out who said what, so you attribute A's remark to B and
have done with it.
--
BMW K1100LT Ducati 750SS Honda CB400F, SL125 & SH50
chateau dot murray at idnet dot com
"What you're proposing to do will involve a lot of time
and hassle for no tangible benefit."

You sure show the signs of someone who feelings have been hurt.

I do stand by my original remarks regarding the level of help available here
on RMT as being limited at best.

Granted at one time this newsgroup was the only on-line source for technical
questions and answers relating to motorcycles however as the internet has
evolved it's membership has declined so much that only a few old timers such
as yourself bother to visit let alone post here.

How many new posts do you see here every day? 10? 15? This place is dead.

When ever I notice a "new" poster here I try to get them all the help they
need and not provide them with partial answers just to stroke my own ego.
Directing them to bike/topic specific forums where they can hookup with like
minded individuals is my goal.

Now if some of you think this is sniping or "stealing" your audience, too
bad. There is nothing you can do about it.

Tom

[TOG@Toil]

<snip>

Post by SC Tom
You sure show the signs of someone who feelings have been hurt.

No, i show the signs of someone who's getting tired of dealing with a
fuckwit. Now *that's* name-calling, if you like.

Post by SC Tom
I do stand by my original remarks regarding the level of help available here
on RMT as being limited at best.
Granted at one time this newsgroup was the only on-line source for technical
questions and answers relating to motorcycles

Utter nonsense.

Post by SC Tom
however as the internet has
evolved it's membership has declined so much that only a few old timers such
as yourself  bother to visit let alone post here.

What "membership" is that, then? It's not a web forum, and it's always
been very low-traffic.

Post by SC Tom
How many new posts do you see here every day? 10? 15? This place is dead.
When ever I notice a "new" poster here I try to get them all the help they
need and not provide them with partial answers just to stroke my own ego.
Directing them to bike/topic specific forums where they can hookup with like
minded individuals is my goal.

You must get on well with Krusty, then. You're two of a kind.

Post by SC Tom
Now if some of you think this is sniping or "stealing" your audience, too
bad. There is nothing you can do about it.

*Boggle* Whoever even thought that, still less suggested it? You have
serious issues to address, you know. You seem to imagine slights,
conversations, remarks and events and then react to these non-existent
happenings. Truly strange.

[SC Tom]

Post by IdaSpode
<snip>

Post by SC Tom
Have you even visited the site?

Yes, it is the reason I decided you were a weasel.

Post by SC Tom
I suspect you have the same low opinion of he GS Resources and Honda SOHC
forums too.

You started off insulting everyone here. For all you know people that post
here are also members of that forum. I belong to a Honda XL and a Honda
Elsinore and unless a question that specifically requires information like
serial number vs. model year, I don't advise people that nobody knows what
they are doing here and to go to one of those boards.
In addition to my XL and Elsinores<plural> I own a 1974 DT360<electronic
ignition in that one> and a DT100. I have a MX125 that I am currently
restoring. I imagine most other members in this newsgroup have similar
stables or histories of owning bikes.
The reason I didn't throw my hat into the ring with an answer was I
thought the answers alread given were excellent and covered the likely
problems.

Post by SC Tom
Using the terms sniping and established forums implies you might be
restraint to the ever changing internet experience.

I stand by my statement. If you had posted that in a moderated forum or on
a web based board, it would have been deleted and you would be banned. It
was and is inappropriate.
Rick

Thank you for making my point, this is a unmoderated newsgroup where
everyone gets to have their say. Like it or hate it, it really does not
matter how you feel. Your opinion is just that, yours and yours alone. If
people could be banned here because someone else took offense, I suspect you
too would have been banned at one time or another.

Now back to the original poster, you can post problems here however the
chances you will get better answers to your problems are higher when posted
on a site that deals specifically with the subject.

Rick, come on back and take another look and read some of the content. There
is a wealth of information and any contributions you make will be most
welcome as it appears you have much experience to offer.

Tom

[Wudsracer]

All the flames aside...
I've seen Tom's posts for several years in another group. I feel that
you are mistaken in your appraisal of his post in this thread.

SC Tom wasn't trying to spam this group, but only offering help in
the form of another resource.


Wudsracer/Jim Cook
Smackover Racing
'06 Gas Gas DE300
'82 Husqvarna XC250
Team LAGNAF

[Rick Cortese]

Post by Wudsracer
All the flames aside...
I've seen Tom's posts for several years in another group. I feel that
you are mistaken in your appraisal of his post in this thread.
SC Tom wasn't trying to spam this group, but only offering help in
the form of another resource.

"You are not really going to get the expert help you need here. These
guys mean well however most don't have a clue on how these old Yamaha
Enduros work.

For the best help, join us over at www.yamahaenduro.com

Tom"

We "don't have a clue" is a compliment?

You need to read his message before you defend his behavior. His post
was in error and inappropriate. You also should read his follow up bash
before you respond to this.

He was wrong for making that statement in the first place. His refusal
to back off, matter of fact he just posted he stands by his statement,
shows him to be small and petty.

I am familiar with your posts and have no beef with your knowledge or
style. You defending this guy in light of his insults is the first post
you have made that gives me pause. I assume it is because you haven't
seen his most recent post.

Rick

[Wudsracer]

*****************************************

Post by Wudsracer
All the flames aside...
I've seen Tom's posts for several years in another group. I feel that
you are mistaken in your appraisal of his post in this thread.
SC Tom wasn't trying to spam this group, but only offering help in
the form of another resource.

**********************************

"SC Tom:"
"You are not really going to get the expert help you need here. These
guys mean well however most don't have a clue on how these old Yamaha
Enduros work.
For the best help, join us over at www.yamahaenduro.com
Tom"

***********

We "don't have a clue" is a compliment?
You need to read his message before you defend his behavior. His post
was in error and inappropriate. You also should read his follow up bash
before you respond to this.
He was wrong for making that statement in the first place. His refusal
to back off, matter of fact he just posted he stands by his statement,
shows him to be small and petty.
I am familiar with your posts and have no beef with your knowledge or
style. You defending this guy in light of his insults is the first post
you have made that gives me pause. I assume it is because you haven't
seen his most recent post.
Rick

*******************************************************
You are correct in that I didn't see any insults when I originally
scanned the post. I only saw the offer of another reference.
I usually sort of "speed read" most of the posts, unless something
comes up where I have experience and might be able to help, or am
trying to learn something for future reference.

You are also correct in that I haven't read anyone's latest post,
except this one. Once I see flames flying, I generally either scan the
posts in that thread very lightly, or just ignore them and go to the
next thread.
I'm not putting myself above anyone, but just don't spend my time
that way. They aren't fun to me.

In this case, I was afraid that there was a misunderstanding of
intent and tried to help.

Good Riding and Wrenching to You All.

Jim

Wudsracer/Jim Cook
Smackover Racing
'06 Gas Gas DE300
'82 Husqvarna XC250
Team LAGNAF

[Pip Luscher]

On Mon, 24 Mar 2008 00:55:36 GMT, "graybeard via MotorcycleKB.com"

Post by graybeard via MotorcycleKB.com
The Yamaha DT 250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.
Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets. Techniques?

3500-4000 rpm open throttle isn't really affected by the idle jet at
all.

Post by graybeard via MotorcycleKB.com
Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?

You need to isolate under what conditions the plug fouls: different
jets work at different throttle positions. Does idling for a couple of
minutes foul it or does riding the bike wide open throttle do it? If
the latter then it's more likely to be running too rich at high speed,
not leaning out. Is the air filter clean and is the airbox intake
clear? Could the main jet have worked loose (unlikely, but...)?

A weak spark will also kill top-end power but IME that's usually in
the form of misfires. Is the plug the right grade?

[.]

Post by graybeard via MotorcycleKB.com
Now that the engine starts, I need to get it running right.
The Yamaha DT  250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.
Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets.

That type of carburetor has a air screw to set the idle mixture. The
beginning setting is 1.5 turns out from fully closed, and
turning the screw clockwise makes the idle misture richer by reducing
the amount of air to the idle circuit.

Post by graybeard via MotorcycleKB.com
Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?

Turning the idle mixture screw counterclockwise will lean up the idle
mixture.

But that type of carburetor didn't have a real choke like a car
carburetor, it had an idle enrichener plunger.

When starting the engine, open the idle enrichener fully and leave the
throttle handle alone.

Also, be sure that your spark plug is the right heat range. A cold
plug will foul quickly.

Also, fuel and oil will accumulate in the crankcase, rapidly fouling
the plug on start up.

Ignition points condition is important to get the maximum voltage at
the spark plug. Be sure the points are clean and properly set.

[Wudsracer]

**************************************************

Post by graybeard via MotorcycleKB.com
Now that the engine starts, I need to get it running right.
The Yamaha DT 250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.
Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets. Techniques?
Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?
Thanks,
Dave

************************************************

From your description of what is happening, I think that you might
have a bad/leaking clutch side crank seal.
This would let the engine suck transmission oil into the combustion
chamber, and would glaze the plug quickly.

Are you losing any transmission oil? (Does the level get lower as
you run the bike?)

Other than that, I would replace the needle jet/jet needle combo.
If it still has the original, then it is surely worn. This would
greatly effect the midrange (making it richer), where you are having
the problem.



Wudsracer/Jim Cook
Smackover Racing
'06 Gas Gas DE300
'82 Husqvarna XC250
Team LAGNAF

[The Older Gentleman]

Post by Wudsracer
From your description of what is happening, I think that you might
have a bad/leaking clutch side crank seal.

Already suggested that one. Possible, especially if the bike has been
standing for a long time and the seal has dried out.

[m***@gmail.com]

Post by graybeard via MotorcycleKB.com
Now that the engine starts, I need to get it running right.
The Yamaha DT 250 Enduro starts and idles o.k. and the low rpm response is
at best 'all right' . But when I crank on the throttle the bike just doesent
pull like it should. At about 3500-4000 rpm the power band flattens out...
feels like it's starving for fuel.
Does anyone have the specs for initial setting for these 2 cycle carbs? Float
setting, number of turns for idle and high speed jets. Techniques?
Another symptom is that the plug fouls quickly. If I burn off the soot on the
plug with a propane troch is starts instantly. But after just one or two runs
the plug is again so fouled it wont start. Is there an adjsustment for
richness?
Thanks,
Dave
--
Message posted via http://www.motorcyclekb.com

DT 250 carb, needs a new o-ring flot bowl main jet leaking, causing rich mix, use small piece gas resistant tubing, also check injector, timing adjustment, new plug, new pilot jet too large, someone tampered with carburator

[The Older Gentleman]

<***@gmail.com> wrote:

<snip>

Another fuckwit with a time machine...