Clearences

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VTR Phoenix
Posts: 710
Joined: Sat Jan 16, 2016 12:07 pm
Location: Slough, Berkshire

Clearences

Post by VTR Phoenix »

I managed to get the bike up and running yesterday, first start in 2 years. Was some back fires and tweaks to the mcct's but what I didn't plan on was the excessive pressure coming out of the oil fill hole once I took the cap off. Enough to actually send oil up and onto the subframe.

Please correct me if I'm wrong but this could be gaskets, valves possibly other issues. I checked the oil, no coolant, I checked the coolant, no oil. So I put it down to valves remaining open, could this be it?

Took rear cover off and measured clearences, Intake is .13 and Exhaust is .25. This was with the feeler gauge having a slight drag to it. Would this be enough to leave the valves open slightly and cause back pressure into the clutch cover and out the oil fill hole? Double checked the timing (which I had previously adjusted) and it was still spot on.

I know they should be .16 and .31
If it aint broke, get your bloody hands off it!
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sirch345
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Location: The West Country.

Re: Clearences

Post by sirch345 »

I would say the oil was more than likely flying out due to the clutch basket rotating at a high speed right under the oil filler opening rather than anything else, so not a problem. Not advisable to remove the filler cap with the engine running. Even if the valves clearances made the valves stay open slightly, it wouldn't pressurise the sump,

Chris.
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VTRDark
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Joined: Sun Mar 18, 2012 9:24 pm

Re: Clearences

Post by VTRDark »

Perfectly normal to be getting pulses of air along with some oil spurting out the filler hole with the engine running and two great big thumping pistons moving up and down. It's crankcase pressure as the crank spins possibly along with some piston ring blow by.
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