No power under load.

[Guest]

This is driving me crazy. At stand still bike idles and revs like it's supposed to. Under a load it just bogs. Even under very light acceleration it bogs.
I wouldn't suspect it isn't the pilot curcuit since it performs perfect on the center stand. Ignition?

1981 GS750 is 100% stock as God (and Suzuki) intended.

[TxGSrider]

Is the airbox lid on tight and are all the boots tight and leak free?

[Number356]

Yes, it's all airtight. The air box lid is on. Why would that make a difference? I'm not intending to sound snippy I'm trying to figure out why my issue is load related. Seems ignition related? It should be so simple but I'm loosing my mind here

[mmattockx]

This is driving me crazy. At stand still bike idles and revs like it's supposed to. Under a load it just bogs. Even under very light acceleration it bogs.

If it revs nicely while sitting in neutral and then won't pull a load that is a textbook symptom of a lean mixture.


Mark

[gustovh]

Ride it and do a plug chop when it bogs down. That will tell you if you are running lean.

V

[Number356]

What's a plug chop? So my plugs look great, I have no popping, I have an extremely great idle. I'm having no other symptoms of lean other than the obvious power loss under load. I have 10.5 to 11 volts going to the coils. Coils test fine.

[Nessism]

Have you pulled the carbs and gone through them. Check the pilots by removing them and holding them up to the light.

[Number356]

Pilots are clear. Slides are free, diaphragms are good.
In my experience I can't recall a lean condition affecting a bike only under a load. I also have no popping which is unusual (to me).
I'm just trying to confirm with you all before pulling the carbs back out. Luckily it's easy.

[dantodd]

Check that all cylinders are firing. Pop each plug wire off and see if the engine stutters the same with each cylinder. Might also check the temp of the headers for each cylinder and see if one is running cooler or hotter than the others.

[Number356]

I wish I were able pop each plug wire. But I can't do that as I'm riding it. The bike purs like a kitten at stand still and I have checked it on the centerstand and confirmed with a timing light that each lead is firing. But I will ride it and then check the temps on each pipe. But it seems as all cylinders bog under load.

[roeme]

The last time I had these symptoms, she wasn't firing on all cylinders - spark was there, but no fire.