AF 175 ring peg position

[john.t5]

Mate had a problem with his Li AF 175 not starting down in Killarney, it bumped but ran like crap and made a couple of nasty bangs so it came home in the van - lucky enough as the tw@7 fell trying to play football with napkins and broke his arm :fb:

Anyway, stripped the top end (just run in brand new kit) and the bottom ring was broken, the main reason I think was that his carb was hanging off and spitting out fuel, therefore drawing in air. Now, I am no expert in these things, I generally know my way around an engine, but I was surprised to see both ring pegs lining up with the intake, I was under the impression that ring pegs & ring gaps shouldn't really be passing any ports with the risk of fouling on them - I take it that this is as the AF kit should be though.

Strangely another guy who travelled up home with us on a GP with an AF175 in it also broke a ring on our way home loose exhaust was the supposed cause.

Any comments would be appreciated.

John

[byron]

but do the rings go as low as the intake port when all assembled...?

a mate did have a broken ring on his AF175 kit recently after only a few miles...
I don't think it was overly examined before fitting though...

[john.t5]

Very good point mate, they probably don't!

[byron]

something's badly wrong if they do...

probably worth slightly taking the edge off the ports inside the barrel, to avoid ring snagging... and check ring gap, piston/bore clearance etc... so all the usual things one needs to do to "bolt-on" kit...