yamaha RD350 4LO

I am facing some problem on my 4LO tt i was unable to troubleshoot:

on idle, the bike is fine.
both exhaust smokes and is hot.

when throttle opening, left exhuast has no smoke and the bike stall.
checked carburettion, all's fine.
check ignition all fine too.
check reeds all fine
no leakage of coolant...

background:
bike running on premix at 33:1.

still facing same prob...

pls help..

rgds
km
owd
sg

 

Crankshaft seals????

 

did you check to see that the needles are both ok and are both properly
moving with the slide?
switch coils.
are both slides moving?
do you mean that the engine stalls as you rev it up out of gear?
(i forget, does this one have constant velocity carbs?)
if so, the left diaphragm is not operating and the left slide is not
lifting.
good luck, sammm

 

Do both slides rise when you turn the throttle? Left side cable could
be off. Check to make sure both slides move together.

Are your float levels correct? A marginally low float level in the
left carb could provide plenty of gas for idle but not enough to make
any power. Is your fuel filter partially clogged? Low fuel flow can
cause this.

A weak ignition coil could cause this. Both plugs will fire when you
look at them during troubleshooting, and at idle, but under load, a
weak coil wouldn't fire the plug. Swap the coils and see if the
problem changes to the right side.

When I assemble an RD, I pressure check it. This requires plugging the
intake and exhaust tracts (both sides, because the center seal on the
crank is only a labyrinth seal) and pressurizing to about 10 psi. If
it leaks down at more than about 1 psi per minute, you have a problem.

Things I've seen on RDs (None of these things are your problem)

Owner in a hurry, and installs left slide in right carb, and vice
versa. You can do this if you put the slides in backwards. Runs really
rich.

Pistons installed backwards with ring gaps in exhaust port.

New owner fills transmission case with two-stroke oil thinking that's
where it's supposed to go. When I see the motor, it's seized, oil tank
empty, transmission filled solid.

 

you mean slides for both carbs are different?

km
owd