no fuel in cylinders

[Anonymous]

Thought I would post this question again since feedback has seemed to hault.
I have a 1982 GS 650GL... I just finished a rebuild on the motor. When the motor cranks...it sounds good... and I can feel the cylinders pull air in when I put my hand on the back of the carbs where the air box would go. All of the jets in the bowl compartment are clear. I have performed most of the cleaning procedures outlined on this site. There is plenty of fuel getting into the bowls. No fuel is being injected to the cylinders. The spark is good...no gas smell in the cylinders when I pull the plugs. Will the air box missing really cause this to happen? I know you can start a car without the air box...I cant see how this would be different. I dont have a new air box yet is the only reason I mention this. Any suggestions?
Thanks
-camaroman

[SqDancerLynn1]

It will start and run without the air box It will just run very lean.Does it even try to fire?? If you spray starting fluid into the carbs Does it try to fire/backfire?? Could the coil power wires be reversed/not the plug wires? If it doesn't try to fire? It may be that the ign spark is there but very weak?? Bad coils?? Make sure that you have aprox 12 v to the ign coils

[Anonymous]

No, It does not even try to fire. When I spray startin fluid in the carbs... It fires...and backfires....caught my engine block on fire..oops...

[redliner1973]

Sounds as though the camshaft was installed 180 out, pulling air in from the exhaust, and pushing out through the intake.

[Anonymous]

But It fires from the exhaust too... It in fact only backfired that once.

[SqDancerLynn1]

OK Need to go back and check the cam timing, have you done a compresion test? Ign timing and coil wiring It sounds like some type of ign prob NOT carb problem. if the ign/timing were Ok it would start with the starting spray, It can be so frustrating but you just have to start checking things to determine the problem

[Anonymous]

While it may start without the airbox, it will definately run like sh#t! Mikuni's and Keihins are VERY tempermental about fuel/air ratios. In newer cars the computer will sense extra air and compensate by adding fuel. I once tried to get around dealer prices for carb to airbox boots using radiator hose. I didn't manage to blow anything up but also couldn't get the 850 out of it's own way either. Does this bike have points? Did you static time it with a test light? Right wires going to right cylinders? Checked that TDC has the correct valves closed? It's something stupid, just keep after it and you'll find it. Bob

[Anonymous]

HAVE YOU RECHECKED YOUR PLUG FIRING ORDER YET

[Anonymous]

Ok,
Thanks for everyones sugguestions....looks like I'm going to have to ake some time off of work and figure this thing out before it starts snowing.
thanks again
-camaroman

[Anonymous]

Re: No Fuel in the Cylinders

I have a 78 GS1000 that I have been trying to get back in shape. Two problems that I had.
1. No gas in cylinders because the little whole in the bottom of the float bowls that allows the gas to flow into a small cylindrical void in the bowl casting that the choke tube sucks the gas out of is plugged up. So I unplugged the hole. Should get gas in the cylinder now.
Wrong.
2. I was trying to star it without the aidbox (w/filter) installed. It wouldn't even pop. Once I put the airbox back on, it started right up.

Good Luck,
Frank