oil filler cap

[bunny]

Hi guys
Just started engine today after having heads skimmed and welded, all fine apart from water in the vee lol whats new, but when i take the oil filler cap off with the engine running the revs drop a little, just drop not stop, is this normal

[jleyton]

Sounds ok to me. Mine only drops 100 rpm or so and, as far as I can tell, my breather system is all ok.

Cheers

Julian.

Ps Don't let the paranoia get to you

[bunny]

Hi
Thank god for that mine drops about that amount cheers

[V Mad]

When the revs drop that's a good sign. It's happens because additional air is sucked into the engine via the breather system; this weakens the mixture which in turn causes revs to drop. The dipstick is also a place where air can get sucked in if the felt washer is missing.

[bunny]

Thanks Chris
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