off and on my gs has ran good. it bogs bad around 6k rpm. but after that runs fine. my charcoal canister is broken. i don't think that matters though. i parked my gs for a month and when i started it again and tried to ride it, it just bogged and didn't want to go anywhere. it backfires every now and then. the carbs have been cleaned out, valves are working good, spark is fine, timing is good, gas is new. i am clueless about the problem. i am just wondering if anyone has had this happen to them and what the problem might be.

Edit:This topic has been moved from the test area.  JD

First thought is that it has an intake leak. Other possibilities are that it could have a rip in the diaphragm or somehow not enough gas getting to one of carbs.
Cool.
Srinath.

still doesn't run right. its not getting enough gas. the compression is only around 90 psi. very weak. do you think compression that low would cause the bike to run for a few minutes and then stall and not go anywhere.

Bike running OK cold, but dying hot, can be due to wrong valve clearances, usually the result of setting or checking the gaps when the engine is less than completely stone cold, or using the wrong spec.

My GS is doing the same thing..only at lower RPM's.  For example when stopped at a stop sign preparing to depart....I have to rev the motor up to 5 - 6 RPM's before the bike will engage....if I try to drive off at a lower RPM the bike bogs and usually dies.  

We've taken the carbs apart and cleaned them, everything looks brand new.  Gas is good.  The strange thing is that the bogging is not consitant...
Every once in a while the bike will also backfire.

I guess the next thing to check is the valves?

ps: I took the california emmissions stuff out and the bike runs the same.

if the charcoal canister isn't hooked up to the tank or anything, does the bike still run fine? also on the left carb there is a hose that connects to the fuel valve. vacuum i think. do you need it. and if the diaphram in the fuel valve doesn't work what happens. my bike acts like it is being starved of fuel. please help, thank you
                      forrest

Quote from: bellstarMy GS is doing the same thing..only at lower RPM's.  For example when stopped at a stop sign preparing to depart....I have to rev the motor up to 5 - 6 RPM's before the bike will engage....if I try to drive off at a lower RPM the bike bogs and usually dies.  

We've taken the carbs apart and cleaned them, everything looks brand new.  Gas is good.  The strange thing is that the bogging is not consitant...
Every once in a while the bike will also backfire.

I guess the next thing to check is the valves?

ps: I took the california emmissions stuff out and the bike runs the same.

This is typical of a super rich mix. I had 42.5 pilots (1 size bigger than right) and it did the same thing. Can also be caused by floats set too high.
Cool.
Srinath.

Quote from: bellstarMy GS is doing the same thing..only at lower RPM's.  For example when stopped at a stop sign preparing to depart....I have to rev the motor up to 5 - 6 RPM's before the bike will engage....if I try to drive off at a lower RPM the bike bogs and usually dies.  

We've taken the carbs apart and cleaned them, everything looks brand new.  Gas is good.  The strange thing is that the bogging is not consitant...
Every once in a while the bike will also backfire.

I guess the next thing to check is the valves?

ps: I took the california emmissions stuff out and the bike runs the same.

If the backfiring and bogging are happening when you open the throttle not when running steady throttle my bet is that it has the floats set high. If the back fire is at steady throttle its lean and more like a feature of it. I would like more info in any case. Put the choke on and see if that makes a diff, open throttle slowly and see if its better than if opened fast. Boggin is like its running out of gas or like its a wettish feel. Is the air filter clean and good, are the hoses from the air box intact and good. More questions man...Also spark plugs, white, black or wet. Valves also should be in spec needless to say...
Cool.
Srinath.

Quote from: qt50riderstill doesn't run right. its not getting enough gas. the compression is only around 90 psi. very weak. do you think compression that low would cause the bike to run for a few minutes and then stall and not go anywhere.

90 Psi compression...Seriously you have far greater problems... However when you measure the compression you are supposed to keep the throttle open and take all the spark plugs out. Failing to do either will turn in a very low reading. Mine made 110 and is a handful when cold. Typically the bike that has so much blow by will be very very very lean when cold and will give you grief when its warming up. But once its warm it behaves better. Mine uses 1 quart of 50wt in 300 miles. So I am betting you are making better than 90psi. Also those screw in guages are better than those press on ones.
Cool.
Srinath.

I just got my bike back from a mechanic and they said the compression is still 90 psi on both cylinders and the carbs are clean and in tune. i looked at the plugs and they are a light black. my bike runs best when first started and then as it warms up it starts running worse and worse untill finally it dies and won't run anymore. the plugs are not wet or fouled. i am wondering if the compression could some how be responsible for it running like this.

Did anyone ever figure out the cause of this problem?  I took my GS out for a ride and experienced the same bogs/stumbling and occasional backfiring.  I did put plugs over my CA model carbs pasages that would connect carbs to charcoal canister if the canister was there (I have an Arizona GS with CA carbs)


Thanks

Adam

I pulled off the plugs on the carb mounted tubes that go to the charcoal canister.  Still, no difference.  Bike starts out riding okay with smooth revs
but then begins to bog and die.  After not wanting to start for a minute or two, it will start up again run smoothly and then repeat the cycle.