Suzuki DR250 stalls off idle

[cramersec]

I have a 1993 DR250. It seemed to not be accelerating well, so i
decided to pull the carb and clean it out. It actually looked pretty
clean, although when i put it back on the bike started much quicker
than usual, so I assumed i had fixed something. Rode it down the road
a couple of miles, and it started to bog. I stopped and it would idle
and re-start fine, but as soon as I cracked the throttle it would
stall. Limped it back home and took it to a local tech, who says he
has gone through the carb multiple times to no avail. Ideas?

Steve

[Albrecht via MotorcycleKB.com]

cramersec wrote:
Ideas?

It's the same problem that I have talked about in this group a bazillion
times.

The idle mixture circuit is plugged up with gum and varnish.

The idle mixture screw is underneath the carburetor, downstream of the
throttle butterfly.

The idle mixture screw is hidden behind an aluminum plug that has to be
drilled out if you want to adjust the screw.

The idle mixture screw controls the single idle mixture port directly above
it.

If you don't want to bother with removing the carburetor and drilling out the
plug so you can do a proper job of cleaning out the port, at least pour about
three ounces of the non-aerosol Berryman B12 Choke and Carburetor Cleaner
into a full tank of gasoline and ride until the problem goes away.

If you want, you can use the aerosol B12 instead. Squirt it down the air jets
until it comes out the idle jets and the single idle port and the three idle
ports next to the throttle butterfly.

http://houseofmotorcycles.bikebandit.com/parts/Suzuki/DR250SEP/1993/994454

[cramersec]

Post by cramersec
Ideas?
It's the same problem that I have talked about in this group a bazillion
times.
The idle mixture circuit is plugged up with gum and varnish.

Sorry I'm so long getting back to you on this. I don't understand your
suggestions. Maybe I wasn't clear, or just don't have the background,
but it idles fine. Isn't that what the idle circuit does?

Post by cramersec
pour about
three ounces of the non-aerosol Berryman B12 Choke and Carburetor Cleaner
into a full tank of gasoline and ride until the problem goes away.

Again, perhaps I was not clear. I can't ride it. It will only idle.

Thanks again

Steve

[Albrecht via MotorcycleKB.com]

Post by cramersec
Sorry I'm so long getting back to you on this. I don't understand your
suggestions. Maybe I wasn't clear, or just don't have the background,
but it idles fine. Isn't that what the idle circuit does?

No, the idle circuit allows the engine to idle and also to accelerate from
idle speed as you open the throttle from fully closed to about 1/4 throttle.

There is one idle outlet port that is controlled by the concealed idle
mixtrue screw.

When the throttle is completely closed, the engine produces enough vacuum at
idle to suck up enough fuel to idle smoothly.

But, when you open the throttle further, vacuuum decreases and the egine
can't suck enough gasoline through dirty passages and ports, so it stalls.

[x***@gmail.com]

What is the needle called on outside of the carbon. The one that has the spring with it.

[Rob Kleinschmidt]

Post by cramersec
I have a 1993 DR250. It seemed to not be accelerating well, so i
decided to pull the carb and clean it out. It actually looked pretty
clean, although when i put it back on the bike started much quicker
than usual, so I assumed i had fixed something. Rode it down the road
a couple of miles, and it started to bog. I stopped and it would idle
and re-start fine, but as soon as I cracked the throttle it would
stall. Limped it back home and took it to a local tech, who says he
has gone through the carb multiple times to no avail. Ideas?

Take a look at the needle to see if it's secured properly.

If I understand you correctly, it started up and ran better
for a couple miles, then began to crap out and run worse.

If this is the case, I'd guess that something you put back
together came undone after a few miles riding.

You've got carburetion, compression and ignition.
While the carb's off, check the compression and
ignition timing too. There are a finite number of things
that can go wrong.

[Jack Hunt]

Post by cramersec
I have a 1993 DR250. It seemed to not be accelerating well, so i
decided to pull the carb and clean it out. It actually looked pretty
clean, although when i put it back on the bike started much quicker
than usual, so I assumed i had fixed something. Rode it down the road
a couple of miles, and it started to bog. I stopped and it would idle
and re-start fine, but as soon as I cracked the throttle it would
stall. Limped it back home and took it to a local tech, who says he
has gone through the carb multiple times to no avail. Ideas?

My '95 DR 250 is doing the same thing. I haven't dug into it yet but it's
almost certainly something blocking the main jet. It idles just fine and runs
up to about half throttle just like nothing is wrong, but when I give it full
throttle it just dies.

I haven't opened it up yet but I'm assuming there's an idle circuit, a
transition circuit, and a main circuit. In my case the main is plugged, and in
your case I'd suspect the transition circuit. This circuit is often a tiny slit
in the throttle bore next to the throttle plate. It would be easy for this slot
to get clogged and not be apparent. Take the carb back off and look for that
slot. Shoot it with compressed air and then see if aerosol carb cleaner will
shoot through it.

--
Jack Hunt IBA#12795, STOC 1870
'99 ST1100, FaST Forward
'95 Suzuki DR250SE
http://www.huntslodge.com