Bizzare starting issue on 86 700F

me too!

so i just cleaned my carbs as well and had the same thought bout the pilot screw and the mysterious hole thats looks like a good place for the pilot screw to go...in reading another posting today, here, i got the impression that the pilot screw is actually the screw between the float bowl cover and the carb body...the one you can only turn like 3/4 of a turn because of the tab that is protruding from the screw end....can anyone confirm this for me?

another question...my 86 vfr700f runs fairly well after cleaning the carbs, and always starts right up, if there were no pilot screw in place, would it run at all? or well?

 

Right,tabed screws are mixture screws....change around the float bowl covers left-to-right and the tab will not be blocked from turning.

smakie, your bike with missing screw would likely be running on 3 cylinders only up to about 3500rpm or so when other cylinder MIGHT start firing again as fuel starts coming from main jet......(i'm guessing here)

 

I realize that I'm digging this up from the grave, but I wanted to bring some closure to this issue.

There were two distinct issues: unaligned carbs, and an iffy starter clutch. The carbs caused the problematic idle. Also, my starter clutch was always slipping in a specific part of the rotational cycle (1 damaged roller/damaged roller bearing surface) which meant that as I (attempted) to crank the engine, it would turn it a half turn or so, the starter clutch would lose grip and slip, and go backwards for a small bit as the cylinders were acting as air springs, then recatch ... and repeat. (Didn't replace it until recently as you may have read as it finally refused to work at all... mmm, metal shavings on the inside)

It does make the unplug-cylinder-to-start make a bit more sense as no combustion BTDC -> no increase in cranking force needed at that specific point in the cycle.

 

Is it fixed now??

 

also curious how that new starter clutch is working out for you...

(the cover bolts of the assembly needed to be torqued down....I hope you did that....they were just finger tight)

 

Yep, it's fixed now. After months of ignoring and working around the issue.

 

Yep, noticed that almost too late. I also replaced the needle bearing in it, just in case. (also, replacing the crankcase gasket was annoying, 20yr+ old gaskets are really ... hard)

 

glad it worked out for you!



(mostly just glad someone is getting use of pieces of my VFR)