Oil in cylinder

Information relating to the Matchless G5 or AJS Model 8 350cc Lightweight
vigo
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Posts: 114
Joined: Sat May 18, 2019 5:50 pm
Location: Cheshire UK

Re: Oil in cylinder

Post by vigo »

Well Max there is some wet sumping, not excessive and I always drain after I've been away. But that doesn't explain how the oil then can leave the cylinder covering the gasket.
vigo
Member
Posts: 114
Joined: Sat May 18, 2019 5:50 pm
Location: Cheshire UK

Re: Oil in cylinder

Post by vigo »

The bike went to Red dragon classics Wrexham, top guys they know their stuff. After 2 days I returned, "did you have to skim the head?" No came the reply. It appears my "nipping" up the 5th cylinder head bolt was not enough and that's all it took. I was a bit cautious as it was an M8 helicoil with only about 10 threads. Maybe I didn't anneal the gasket properly too, who knows.
Oil in cylinder they think came from wetsumping and recorded 200ml overnight. With piston tdc I get very little.
They also think my added online fuel filter could along with tank and carb filters have caused fuel starvation and binned it.
Anyway I took the bike away and for the first time in 3yrs was able to ride a couple of miles. Thanks RDC.
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clanger9
Posts: 1165
Joined: Sat Jun 20, 2015 9:38 am
Location: Chester, UK

Re: Oil in cylinder

Post by clanger9 »

Excellent, glad you hear you finally got it sorted Mike!
Interesting to learn that the 5th head bolt tightness is so critical...
1989 Moto Morini Dart 350
1993 Ducati 750SS
vigo
Member
Posts: 114
Joined: Sat May 18, 2019 5:50 pm
Location: Cheshire UK

Re: Oil in cylinder

Post by vigo »

This little G5 has thrown up another mystery. I retorqued the head after about 100mls as the old oil in cylinder symptoms had returned. About half a turn on each bolt and did pull the head down as I had to adjust the push rods. Goes ok now but spits back occasionally.
Anyway the reason for writing is to ride over 42 mph (speedo is accurate) the motor seems to rev far to high, about to climb out of the frame and cannot imagine going to 50 or 60 let alone claimed 73.
Seems very low geared, could an unduly small sprocket be fitted somewhere and if so where would be likely.
Any thoughts gents.
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