SR Barrel

[Monty]

Stupid question
Guy at the club had said kit and dropped a ring that scored his barrel badly
re board out 3 x over he says to clear the score
Rebuilt but when its warms up sounds like the anvil chorus
Been down the squish piston hitting the top, bottom, replaced his crank all bearings etc. no change
Question
What holds the sleeve into the ali casting?
Could the thinner sleeve be moving up and down with the piston.
He thinks its piston slap but its too tinny ping ping kind of noise for my liking
Comments other than its Sh1t as he ain't got a lot or readys after all he has done.

[tony]

Big end gone?

[byron]

I had an SR barrel bored out to 66mm, and it was fine.
Only took it off after nearly 3000 miles to fit a Mugello.
The problem may lie elsewhere.
Apart from the din, does it run ok ?

[Monty]

I had an SR barrel bored out to 66mm, and it was fine.
Only took it off after nearly 3000 miles to fit a Mugello.
The problem may lie elsewhere.
Apart from the din, does it run ok ?

Yes but he is not brave enough to put in the miles.
He found that his crank mag side bearing was shot with the inner running loose on the crank, so he replaced it with a SIL one, with new bearings and oil seal. Twice round the car park and its back.
I would have sworn at first it was hitting the head but its not, hence my question is the liner moving?

[bristolmod]

I think SR barrels may be prone to a bit more noise for some reason. I've had 3 so far on different bikes, and the first 2 were a tad rattly at times (all were bored to 66mm BTW)

The present one is fine although the piston / bore clearence on that was only 3 thou. with the first 2 at 4 thou and 3.5 thou

All 3 ran very well

Chris

[Ian Hepworth]

If it's a genuine SR barrel then the liner won't be moving - the outside of the liner is ribbed so that when the ally bit is cast round it the liner won't move.

[Monty]

Thanks Ian
Said club member calls it an SR barrel but it was quote a £110 ebay kit that ran fine until he dropped the piston ring.

[drunkmunkey6969]

Thanks Ian
Said club member calls it an SR barrel but it was quote a £110 ebay kit that ran fine until he dropped the piston ring.

One of these beauties? http://www.phpbb88.com/scooterotica/vie ... ooterotica

[Ian Hepworth]

Even if it's just a straight liner then the head should hold it in place.
Wouldn't be suprised it it wasn't though.

[Monty]

Thanks guys
Yes I think it is one of the ones that we have seen so many problems with
My understanding was that the ali casting was made with all the basic transfers and ports in the cast, the casting skimmed and the sleeve pushed in. My guy was told that the sleeve was pinned in???
At the end of the day if the liner spigots don't bottom out in the crank mouth the liner can be going up and down once its warmed up.
Its the only answer I have as this guy has stripped this motor about 5 times and after all the input from the club its exactly as it was 2 months ago.
My suggestion was to bin it and re-bore his original SIL 150 to 175, but he likes the idea of the kit..