Help with misfire/poor carburation??

[crayonjota]

Guys,

My 1980 GS1000E started to feel a bit hesistant this afternoon and I could only really rev it to about 7000rpm before the power went away, with a misfire/full lack of power.

I took the bike home and checked the plugs all good, light grey. I took the airbox off and cleaned it out and took the carbs off and gave them a good shot of carb cleaner. Now the bike pulls like a train up to 5000rpm then the power just goes. I can hold the throttle wide open in the yard and the tacho goes no higher than 7000rpm! It has to be fuel delivery, but what is the deal. Is it fuel line, fuel filter or should I have the carbs apart?

Thanks CJ

[robinjo]

At what setting is your ignition timed at the moment?

[crayonjota]

At what setting is your ignition timed at the moment?

Ha! Good question and no answer. I had to convert the CDI back to points as it was screwed and there are no parts available here (postage is screwed up too, so no ebay or mail order!) The timing is set by hand and ear. No backplate markings and toyota points! I did a long trip and had to retard the ignition a little about a week ago, but it was pulling strong up to redline. I have a nice strong spark, the plugs are good and oh, the fuel tap is broken so I have an inline fuel cutoff (brass tap) to get me by. The thing starts on the button and runs well on part/full throttle up to where it comes on cam. I had a problem before with the fuel line routing, causing fuel starvation. It feels a little like the same issue, but the fuel line hasn't moved. When the tank gets real low it exhibits similar symptoms, but the tank is now full. THe more I think about it the more I feel it is fuel delivery rather than ignition...??? :?

[Sandy]

I'd look to the ignition or electrical. Sitting in neutral the bike should rev to the moon with hardly any throttle or gas.

[crayonjota]

I'd look to the ignition or electrical. Sitting in neutral the bike should rev to the moon with hardly any throttle or gas.

YES

YOU ARE RIGHT! THANKS!

It turns out that after pulling the carbs and going through the fuel system that my efforts turned out to be preventative maintainence (?) or something.. Today I got up early and went through the electrics step by step and resolved the problem.

It was a bad coil!!!!!!! There was a spark being generated, but a little weak. Swaping out another coil made the whole thing sing and I am happy to say all is well that ends well. CJ

[Sandy]

Glad things worked out. This forum has help me out in the past too.