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Step 2: Adjustment and Performance Tweaking

1097 Views 7 Replies 5 Participants Last post by  izak

After much help and many hours of work my first project bike starts up! Now its time to learn the ins and outs of adjustment and getting my new found love to purr! Below are a list of questions and concerns I have with the way she runs as of today;

The main issue in front of me is that I start her up with the choke all the way out, but as she runs I get periodic and unprompted "acceleration or revving". I've tried to slowly push in my choke about a minute into starting it up, and that seems help with the random idle acceleration, but often as I push in the choke to quell the roar of my engine she dies out (the speed at which it dies is determined by how quickly I push in the choke).

I think maybe it is an imbalance of air to fuel ratio? I installed a PULL-ONLY throttle cable on a push-pull control, but I'm tested repeatedly and the butterflies are snapping back. Not sure its a throttle
cable/control issue. Maybe my Accelerator Pump (no idea what this does)?


Also I put in a full bottle of Seafoam into an almost full tank of gas. Good idea? I heard it helps clean out the engine. Lots of farting and popping when I pull the throttle while idling.

Thanks all,
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Did you consider reading the mix ratio directions on the side of the can of SeaFoam????

As a couple of thoughts......
I'd suggest to do 2 things.

1.) Drain your tank. Dump it into your car or pickup and top off the tank.
2.) Get Larry Cargill's carb book. Read it
3.) Pull the carbs and follow Larry's book.
4.) Fill the tank with fresh fuel.

For future reference.....when some is good, more isn't necessarily better.

These products only need a few ounces per gallon. IIRC, a Seafoam can is 16 ounces.
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Any thought on what I've diagnosed?
I presume you still have the original Keihin carbs on your bike. Try to turn the 2 mixture screws ( front , lower side ) all the way in . Then turn both out 2 and a half turns . Try to start bike ....
clean the carbs properly then move on lol
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So it's still a carb issue then? Not necessarily the Accelerator Pump
Once again you need to get Larry's book and follow instructions inside.
The accelerator pump is part of the carburator and , yes, if it is defective or it's diaphragm is perished , it might be part of the problem.
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