Tracing airleaks

[coaster]

....@coaster. - it's a proper reed block case, we didn't open that any more, the hole’s big enough already...

It was the transfers in the casing I was referring too, I don't know about the kit you are using but the transfers required a lot of 'matching' for the LML 5 port cylinder fitted to my LML reed casing and there is precious little metal to play with

[mick1]

@mick1 - you mean the drive side or the flywheel side? I always though a blown drive side seal mention oil p!$$ing out the breather like the Exxon Valdez?

@coaster. - it's a proper reed block case, we didn't open that any more, the hole’s big enough already...

@ goldeneye. - I'm sure It did but am gongt to strip it all off and check again anyway, one of the scenes that held the block down had to be retapped a bit, I'm wondering if it worked loose now... i'll try the wd 40 check first though, cheers. Won't be back at it till the end of the week now as it's in my brothers garage 70 miles away...

That method certainly works on a Lambretta so should work on a Vespa. As for the oil coming out of the breather...air's thinner than the oil so a small leak might not push the oil out but suck the air in.....

[rosscla]

....@coaster. - it's a proper reed block case, we didn't open that any more, the hole’s big enough already...

It was the transfers in the casing I was referring too, I don't know about the kit you are using but the transfers required a lot of 'matching' for the LML 5 port cylinder fitted to my LML reed casing and there is precious little metal to play with

Ah ok, then no, I think there's still enough, just matched to gasket', cheers.

[Speed Demon]

Best bet is simply to test it with a leak down kit. There was an article about making one for a few quid in that scooter magazine that everyone slags off...

[rosscla]

Which issue was that again? I think I remember reading it and I can see how that works on a Lambretta with a manifold and a stub (if you mean the bike tube one) but how'd you make it work on a PX motor?

[Speed Demon]

Which issue was that again? I think I remember reading it and I can see how that works on a Lambretta with a manifold and a stub (if you mean the bike tube one) but how'd you make it work on a PX motor?

It was in issue 322. Difficult to make it work with a stock carb but it'll work fine if you bolt on a manifold for a 30mm carb etc.

[coaster]

Which issue was that again? I think I remember reading it and I can see how that works on a Lambretta with a manifold and a stub (if you mean the bike tube one) but how'd you make it work on a PX motor?

It was in issue 322. Difficult to make it work with a stock carb but it'll work fine if you bolt on a manifold for a 30mm carb etc.

Or you could make a blanking plate to bolt down over the inlet port in the casing and then seal the other end of the inner tube. The original poster did that on his Lambretta I seem to remember but it got refined along the way.

[rosscla]

Good ideas, a blanking plate to go over the air box hole would also help trace if it's the reed block or air box. Thanks.


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[rosscla]

I think we found the problem

[goldeneye]

aye, no carb fitted will let a canny bit of extra air in . no carb box screw I see?