Thread: Back to the F100 Yamaha....

So not reading your service manual these comments may be all wet but when I synchronize Yamaha Carbs I have the linkage loose, Nothing touching the timing advance cam on the throttle linkage, pencils with the eraser end lightly holding the butterflies closed on all butterflies at the same time (can get tricky) I lock down the lefthand thread screw that keeps all the linkages together so all butterflies open in perfect union. Does your engine have the same adjustment as the Yamaha's I have experience synchronizing?

Originally Posted by Rojo

So not reading your service manual these comments may be all wet but when I synchronize Yamaha Carbs I have the linkage loose, Nothing touching the timing advance cam on the throttle linkage, pencils with the eraser end lightly holding the butterflies closed on all butterflies at the same time (can get tricky) I lock down the lefthand thread screw that keeps all the linkages together so all butterflies open in perfect union. Does your engine have the same adjustment as the Yamaha's I have experience synchronizing?

I'll take a pic and show you. Sounds similar. One thing though, I don't think mine would run with all the butterflies completely closed, dono. I think mine are ever so slightly open.

And if I can remove the advance with it's linkage, that would be great, it's in the way of feeling the vacuum on the bottom carb.

Great feedback John. And yeah, I suppose I should read the manual, doh!

Slab the very first thing you do is back off the idle screw till it does not touch. Then close all butterflies. You will never get it synchronized unless the linkage is first synchronized. Otherwise all the butterflies will open at a different rate making the engine idle rough. Once the linkage & butterflies are in sync then you turn the idle screw out opening all the same amount at the same time.

Certainly sounds like a fella needs 2 pairs of hands at least.