Scooterotica

Has anyone else had issues with fitting the thicker, longer cylinder studs with a GT186 kit? I've just tried to fit them, and one is very tight through one of the exhaust cylinder holes.

I had trouble with the MB cylinder studs,it seems they are thicker than normal studs.In the end I got some Vespa studs made for a P200 and fit them.
http://www.ebay.co.uk/itm/EXTENDED-CYLI ... SwubRXETSm

Very common problem with all sorts of kits and casings, even including standard factory motors.

When this came up as a topic previously, I had one contributor contact me to say that he had stripped down his factory assembled SIL 200 motor a rebuild and rebore. Bearing in mind that this was a motor that had already been together without issue for thousands of miles (no change of barrel or casing), he was confused when he couldn't reassemble with the thicker studs that he'd bought for the rebuild. A change back to the original studs cured the issue.

Adam

To be honest, I should of known better. I had issues with an RB200 cylinder, using these studs, on an Indian casing. I've now ordered some P200 ones. ( expensive ) Lesson learnt....

Unless there is a major calamity with any heat treatment, the weakest part of a stud is the root of the last thread, unless the OD is turned down to be smaller, called "waisted". This is the case with well made high performance studs.
Just making fatter studs is a waste of time and material, showing a lack of understanding of the engineering principles involved. It also seems to cause frequent fitting problems.

I always though that there should be a clear gap between the stud and the barrel. Can't remember why. Is this true?

To allow the cylinder to expand.

I've received some P200 studs and alls well. Lesson learnt.

EddieStone wrote:I always though that there should be a clear gap between the stud and the barrel. Can't remember why. Is this true?

Harry barlow at proporting used a long series drill on mines opened them up by .5mm slides on a treat