750 Crank Pasing Again.

1

1993 Vmax4 750

New member
Back to the same old question. Is this sled out of phase?
I have a 92 750. My problem is oil fouling of plugs. Engine seams to run ok, accept this issue. Ive check the oil adjustment, and it is ok. Compression is all over 120 on all cylinders.
I did take a measurement of the piton heights, with a vernier caliper, measured from the top of plug hole, with #1 at TDC.
#1 was 1 1/4 inches
#2 was 3 1/4
#3 was 2 1/2
#4 was 2 1/2

So the question is. How do you tell how it was set up? I keep reading it could be 90 or 180? Than are gaskets available to rebuild this thing, and who in Ontario canada, would be able to sync these cranks, and weld them? Will try to post picks of exhaust so you can see oil seeping out on one side compared to other. Oily side is 1&2 the dry is 3&4
 

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If your measurements are precise and #1 is TDC, #2 BDC with three and Four even at half stroke, that would be correct for 90 Degree.

that said, if memory serves.. If it did go out of phase, I believe the symptoms show up on the NON mag/clutch side.. (3 & 4 should be showing the symptoms)..

In your pics, there appears to be some oil/fuel on the side that should be good, even if out of phase..

Now as far as syncing the carbs, I would rule that out to be honest with ya..
By design, it seems the Vmax4 carbs are EXTREMELY unlikely to go out of sync to an extent of causing an issue like this..

the fact that both cylinders are "Appearing" to be having an issue is a bit concerning with the known 750 crank issues, but in this case, they are both also sharing a Y pipe.. So it is possible anyway, this could be a single carb issue, causing enough excess fuel to enter the pipe, that the back flow (so to speak) is giving the illusion of a two carb/cylinder issue..

I am hoping this is a needle & seat issue? which is one of the first things I would check, while doing an over all carb cleaning..
 
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Welcome..
as far as compression, I would hope to see 120lbs across the board..

But let me say right now.. as little air as these move, don't expect to see a good reading, especially if your comp gauge has a hose on it, and also due to the location of the shrader Valve? (Base of hose, base of gauge? etc)..

When I first rebuilt my engine, I ran a comp test and got an even 70lbs across the board.. I about fainted, WHAT???

turns out my less then stellar gauge was WAY wrong, even though it was brand new!

so with these variables in mind, I'd be looking for evenness above Numbers..

just went back and read that you already ran a comp test, and got a solid 120lb plus on each cylinder. I'd say you are good there!
 
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