I have to disagree here. Engine vacuume is the result of a purely
mechanical situation of RPM, and throttle opening. (This assumes that there are
no vacuume operated devices in use.) Poor timing can result in lower vaccume
only because You have to open the throttle more to atain the same RPM. What can
drastically affect Low RPM Vacuume is cam timing, durration, and overlap. Once
the cam is installed, it can't change..
As for the vapor comming out of the engine, a new PCV valve should cure that
problem. Having one with no guts was a gaureentee for it to run bad..
As for the WD-40 trick, it does work, but can be dangerous. When I was
building bike engines, we always use a old oil squirt can. (Small canister with
long tube and small pump handle) filled with water. Doesn't affect the running
of the engine, but will generate a noticable slurping sound when leaks are
found. I still use this mothod today...
You're almost there! Just a little more work, then ZOOOOM !!
Rich
>
>Timing plays an important factor in correct vacum readings so make sure
>it is correct first. As you advance/retard the timing the vacum guage
>reading will change. If the engine is blowing oil out of the breather I
>would also suggest checking the compression. You may have enough blowby
>that the engine intake stroke is not creating the required vacum.
>
>P.S. An old trick to finding vacum leaks (here is where I put in the
>disclaimer that WD 40 was flamable and explosive you should be very
>careful not to use it where it could start a fire or get hot enough to
>explode) is to use the old formula of WD 40 (flamable) and with the
>engine running sparingly spray all points that are suspected leaks. If
>you hear the engine RPM pick up you have found a leak.
>
>
>Norm Garland
>nfgjr@juno.com
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