loss of vacuum

npca-vike · Post by **npca-vike** » Tue Sep 09, 2003 12:25 am

I managed to get the wiring sorted out and the engine is running but it idles rough - as soon as it is accelerated it smoothes out fine. My vacuum guage is saying I have no, or only a little, vacuum at idle. Any problem areas with this engine that could cause such a loss of vacuum?

npca-rockpatrol · Post by **npca-rockpatrol** » Tue Sep 09, 2003 1:18 pm

i just finished this problem with mine also....it turned out to be a worn throttle shaft...this allows the butterfly to stay open and not create a good vacuum at idle...checked around and found carb shops in my area to run about 60-75 to rebush the shaft...i ended up using some teflon shimms and it perfects like a kitten now...good luck....ty

npca-vike · Post by **npca-vike** » Tue Sep 09, 2003 3:22 pm

Tnanks. I had the carb rebuilt by Redline in Winnepeg and there is no slop in the throttle shaft at all. Anyone had problems with the heat riser chamber rotting out and allowing vacuum to be lost through the exhaust manifold? The reason I ask is that I have done water and propane testing to all external areas and nothing shows re a leak around the gaskets at all. I did have concerns about design of the intake to exhaust manifold connection via the heat riser section - rust in that area etc...- and hence my question.

npca-clack · Post by **npca-clack** » Wed Sep 10, 2003 12:38 pm

Hey Vike- I had the same problem with my carb too, loose shaft I did end up taking mine to the carb shop I had no idea about teflon shims or where even to find things like that. Just wondering if it got fixed or not. Jeez they usually idele perfect and smooth. No posssibility of leak in vacuum advance is ther? Any way good luck. Carl (HikeandBike)

npca-vike · Post by **npca-vike** » Wed Sep 10, 2003 3:53 pm

had the vaccuum advance disconnected to use that vaccuum port to attach the vaccuum guage so the advance is not part of this. Thanks.