TTR125 smoking

[Lindel]

I am having trouble with a TTR125L 2001 model. It came in smoking.
Upon dissassembly, I found lots of wear in the cylinder. I replaced the
cylinder, rings etc... with new Yamaha parts. I followed the prescribed
break in procedure in the service manual. It still smokes after it gets
hot.

I then pulled the head and swapped it for another from another bike,
thinking that it could be valve seals but it still smokes after it gets
hot. No change.

What should I check next?
Any help would be appreciated.
Lindel


--

[Fwoar]

fresh fuel? - thinking along the contaminated with 2stroke oil .

gear oil or sorts down the pipe.

breather to airbox pressuring oil to it?

not alot else if it has been changed
--
Daron

ebay? - http://tinyurl.com/ykgh

Post by Lindel
I am having trouble with a TTR125L 2001 model. It came in smoking.
Upon dissassembly, I found lots of wear in the cylinder. I replaced the
cylinder, rings etc... with new Yamaha parts. I followed the prescribed
break in procedure in the service manual. It still smokes after it gets
hot.
I then pulled the head and swapped it for another from another bike,
thinking that it could be valve seals but it still smokes after it gets
hot. No change.
What should I check next?
Any help would be appreciated.
Lindel
--

[The Older Gentleman]

Post by Fwoar
fresh fuel? - thinking along the contaminated with 2stroke oil .

It's a four-stroke, you buffoon.

http://www.yamaha-motor.com/sport/products/modelspecs/237/0/specs.aspx

[Fwoar]

yes I realise it's a 4 stroke, but sometimes ppl put 2 stroke in them cos
thats all they had in the shed.

hence the fuel is "contaminated" with 2 stoke oil......or does that mean
premix to you?

get my drift??
--
Daron

ebay? - http://tinyurl.com/ykgh

Post by The Older Gentleman

Post by Fwoar
fresh fuel? - thinking along the contaminated with 2stroke oil .

It's a four-stroke, you buffoon.
http://www.yamaha-motor.com/sport/products/modelspecs/237/0/specs.aspx
--
Trophy 1200 750SS CB400F CD250 Z650
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5 The bells, the bells.....

[The Older Gentleman]

Post by Fwoar
yes I realise it's a 4 stroke, but sometimes ppl put 2 stroke in them cos
thats all they had in the shed.

I have never, ever heard of anyone putting two-stroke pre-mix into a
four-stroke's fuel tank.

Post by Fwoar
hence the fuel is "contaminated" with 2 stoke oil......or does that mean
premix to you?

Yes, it does.

Post by Fwoar
get my drift??

Yes. You're definitely a buffoon.

[Fwoar]

Post by The Older Gentleman
I have never, ever heard of anyone putting two-stroke pre-mix into a
four-stroke's fuel tank.

well, it happens quite a bit.

twat ;-)

[The Older Gentleman]

Post by Fwoar

Post by The Older Gentleman
I have never, ever heard of anyone putting two-stroke pre-mix into a
four-stroke's fuel tank.

well, it happens quite a bit.
twat ;-)

You'd have to be, to do it.


Still news to me, and hardly likely to be the cause of this problem, but
wtf.

[B-12]

Post by The Older Gentleman

Post by Fwoar

Post by The Older Gentleman
I have never, ever heard of anyone putting two-stroke pre-mix into a
four-stroke's fuel tank.

well, it happens quite a bit.
twat ;-)

You'd have to be, to do it.
Still news to me, and hardly likely to be the cause of this problem, but
wtf.

I dunno how nozzles at service station diesel pumps are identified
across the pond, but the nozzles here are green.

A wealthy rock star riding his BMW across Canada on the way to Alaska
wrote about
pulling into a service station and stopping near the diesel pump and a
helpful teenaged attendant handed him the green nozzle so he filled his
tank with diesel.

The kid said, "So, your motorcycle runs on diesel, eh?"

[The Older Gentleman]

Post by B-12

Post by The Older Gentleman

Post by Fwoar

Post by The Older Gentleman
I have never, ever heard of anyone putting two-stroke pre-mix into a
four-stroke's fuel tank.

well, it happens quite a bit.
twat ;-)

You'd have to be, to do it.
Still news to me, and hardly likely to be the cause of this problem, but
wtf.

I dunno how nozzles at service station diesel pumps are identified
across the pond, but the nozzles here are green.
A wealthy rock star riding his BMW across Canada on the way to Alaska
wrote about
pulling into a service station and stopping near the diesel pump and a
helpful teenaged attendant handed him the green nozzle so he filled his
tank with diesel.
The kid said, "So, your motorcycle runs on diesel, eh?"

Strewth. I can see a lot of Yank tourists in hire cars having fun here,
because we use green for unleaded. Diesel nozzles are black. The few
lead replacement petrol nozzles still knocking around are red.

Many years ago, you used to get petroil dispensing pumnps in France, for
the zillions of little Mobylettes and Motobecanes. I hadn't seen one in
literally a couple of decades or more, and then earlier this summer I
pulled into a rural filling station that still had one. Memories....

[Lindel]

I have not put in premix or diesel fuel. I drained the tank and
replaced the fuel with fresh gas before I did the tear down. I wanted
to make sure it was not contaminated before I started it up on the new
top end.

I used standard auto 10w40 valvoline oil. Would that cause the rings
not to seat properly? If not what else may cause the rings not to seat?
What could I do about it now? DO I need to replace the rings again. I
do know that they are in correct. symbols up and turned so that the
gaps were postioned according to the service manual.

Lindel

Post by The Older Gentleman

Post by B-12

Post by The Older Gentleman

Post by Fwoar

Post by The Older Gentleman
I have never, ever heard of anyone putting two-stroke pre-mix
into a four-stroke's fuel tank.

well, it happens quite a bit.
twat ;-)

You'd have to be, to do it.
Still news to me, and hardly likely to be the cause of this
problem, but wtf.

I dunno how nozzles at service station diesel pumps are identified
across the pond, but the nozzles here are green.
A wealthy rock star riding his BMW across Canada on the way to
Alaska wrote about
pulling into a service station and stopping near the diesel pump
and a helpful teenaged attendant handed him the green nozzle so he
filled his tank with diesel.
The kid said, "So, your motorcycle runs on diesel, eh?"

Strewth. I can see a lot of Yank tourists in hire cars having fun
here, because we use green for unleaded. Diesel nozzles are black.
The few lead replacement petrol nozzles still knocking around are red.
Many years ago, you used to get petroil dispensing pumnps in France,
for the zillions of little Mobylettes and Motobecanes. I hadn't seen
one in literally a couple of decades or more, and then earlier this
summer I pulled into a rural filling station that still had one.
Memories....

--

[B-12]

Post by Lindel
I used standard auto 10w40 valvoline oil. Would that cause the rings
not to seat properly?

Did the oil control rings have corrugated ring expanders in the box?
Did you install them with the oil control rings?

If not what else may cause the rings not to seat?

Maybe the light oil glazed on the cylinder walls when it got hot too
fast? That would happen if the two top rings didn't seat and hot gasses
blew past the top rings.

Post by Lindel
What could I do about it now? DO I need to replace the rings again. I
do know that they are in correct. symbols up and turned so that the
gaps were postioned according to the service manual.

Have you ever heard of the Bon Ami trick? Old time mechanics used to
dribble kitchen cleanser into the carburetor throats as the engine ran
at high speed. The abrasive particles would help seat the piston rings.

As I recall, Chrysler had a terrible time with ring seating on their
Plymouth models in the 1950's. (1) But old time mechanics straightened
out the problems with Bon Ami.

Trying this technique is totally up to you, and DO NOT try it on an
engine with a cylinder that has a chrome plated or Nikasil bore, you'll
ruin the cylinder. Only do this to engines with cast iron or steel
cylinder liners.

(Daddy, what's a Plymouth? I dunno son, ask your grandpa about
Studebakers and Packards and Edsels and Ramblers.)

[The Older Gentleman]

Post by B-12
Have you ever heard of the Bon Ami trick? Old time mechanics used to
dribble kitchen cleanser into the carburetor throats as the engine ran
at high speed. The abrasive particles would help seat the piston rings.
As I recall, Chrysler had a terrible time with ring seating on their
Plymouth models in the 1950's. (1) But old time mechanics straightened
out the problems with Bon Ami.

I really think that cylinder, piston and ring technology has moved on in
the intervening half century, mark you.

[Ted Mittelstaedt]

Post by Lindel
I have not put in premix or diesel fuel. I drained the tank and
replaced the fuel with fresh gas before I did the tear down. I wanted
to make sure it was not contaminated before I started it up on the new
top end.
I used standard auto 10w40 valvoline oil. Would that cause the rings
not to seat properly? If not what else may cause the rings not to seat?
What could I do about it now? DO I need to replace the rings again. I
do know that they are in correct. symbols up and turned so that the
gaps were postioned according to the service manual.

OK hold on here,

You said:

"..Upon dissassembly, I found lots of wear in the cylinder. I replaced the
cylinder, rings etc... with new..."

You said you put a new cylinder in, but did you by chance use a micrometer
to
assure yourself that it was, in fact, round? And that it was the right size
for the
piston? And did you mic out the piston? Did you install the rings in the
cylinder
without the piston and measure the ring gap to be sure it was in spec? Did
you
run a cylinder hone to put an initial crosshatch on the cylinder?

Just buying new parts does not relieve you of the responsibility to measure,
if you just assumed the new parts would all fit perfectly, you are asking
for
trouble.

Maybe instead of putting a worn piston with new rings into a new cylinder,
you should have bought a new oversized piston and rings, and bored out the
cylinder?

Ted

[Lindel]

Post by Ted Mittelstaedt

Post by Lindel
I have not put in premix or diesel fuel. I drained the tank and
replaced the fuel with fresh gas before I did the tear down. I
wanted to make sure it was not contaminated before I started it up
on the new top end.
I used standard auto 10w40 valvoline oil. Would that cause the rings
not to seat properly? If not what else may cause the rings not to
seat? What could I do about it now? DO I need to replace the rings
again. I do know that they are in correct. symbols up and turned so
that the gaps were postioned according to the service manual.

OK hold on here,
"..Upon dissassembly, I found lots of wear in the cylinder. I
replaced the cylinder, rings etc... with new..."
You said you put a new cylinder in, but did you by chance use a
micrometer to
assure yourself that it was, in fact, round? And that it was the
right size for the
piston? And did you mic out the piston? Did you install the rings
in the cylinder
without the piston and measure the ring gap to be sure it was in
spec? Did you
run a cylinder hone to put an initial crosshatch on the cylinder?
Just buying new parts does not relieve you of the responsibility to
measure, if you just assumed the new parts would all fit perfectly,
you are asking for
trouble.
Maybe instead of putting a worn piston with new rings into a new
cylinder, you should have bought a new oversized piston and rings,
and bored out the cylinder?
Ted

I used all new parts. I did not run a hone to cross hatch as it had a
cross hatch pattern in it already. I did put the rings in the cylinder
and check the ring end gap. I did not measure the cylinder and piston
since the rings were pefect and they fit the new piston. I always
thought that using brand new factory parts was the best route. I
thought that having the cylinder machined was an alternative when
trying to get out cheap.

So do I need to take it back apart and cross hatch the cylinder with a
hone and replace the rings and try again?

I really was trying to achieve a like new result.
Thanks

Lindel


--

[Rick Cortese]

<snip>

Post by Lindel
So do I need to take it back apart and cross hatch the cylinder with a
hone and replace the rings and try again?

Did you do a compression check or leak down test?

If it has good compression and passes a leak down test, that will pretty
much tell you the rings and valve seats are OK. You don't want to do
another ring job if you don't have to.

I'm not sure how the oil is run up to the top end of a Yamaha, but on my
Honda thumpers it is run through the casting of the cylinder and
requires O-rings be placed on studs. More then one owner has had
problems with leaving out these O-rings or putting them in wrong.

If it really smokes bad when you first start and cleans up in a minute
or two I would tend to blame it on valve seals.

What I am trying to say is there are other reasons an engine will smoke.
Make sure you check those out too before you proceed.

[B-12]

Post by Lindel

Post by Ted Mittelstaedt
Maybe instead of putting a worn piston with new rings into a new
cylinder, you should have bought a new oversized piston and rings,
and bored out the cylinder?

I used all new parts. I did not run a hone to cross hatch as it had a
cross hatch pattern in it already. I did put the rings in the cylinder
and check the ring end gap. I did not measure the cylinder and piston
since the rings were pefect and they fit the new piston. I always
thought that using brand new factory parts was the best route. I
thought that having the cylinder machined was an alternative when
trying to get out cheap.
So do I need to take it back apart and cross hatch the cylinder with a
hone and replace the rings and try again?

Well, actually, since the 1980's. Japanese motorcycles have been built
with a very fine finish in the cast iron or steel cylinder bores and
the piston-to-cylinder wall clearance has been very small, like about
1/1000th of an inch or maybe 0.0015.

Since you don't seem to be the owner of this machine, it's possible
that it has been "repaired" by some old time mechanic who just
*ass*-umed that a cross-hatched hone pattern was the way to go, using
the older theory that the honing left scratches that held needed oil
during breaking.

My friend who owned a motorcycle speed shop bought a special Sunnen
hone that micro-finished the over-bored cylinders that he was supplying
for his customers when all the rage was big bore kits for drag racing.

When he went out of business, another friend bought the hone.

If you decide to buy a whole new cylinder and a new piston and rings
(or overbore the cylinder you have and use the next sized piston and
rings), you still need to
"mike" the parts to find out what the clearances are and compare them
to what the shop manual recommends.

"Miking" the bore of a cylinder requires either a telescoping bore
gauge or a set of external machinist's dividers. After expanding the
bore gauge or dividers to the internal diameter of the cylinder, they
are then measured with a large micrometer, perhaps a 2 inch to 3 inch
micrometer in your case.

If this all sounds complicated, you might want to place yourself at the
mercy of a motorcycle machine shop.

But, first ask the old geezer in the shop if he still believes in
honing cylinders with a cross-hatch pattern... ;-)