I have just brought myself a 200 with a top end rattle, I removed the barrel & checked the ring gap a) at the very top of the barrel and then immediatly below the step, and there is a 0.5mm diffrence which I think tells me it needs a rebore. all the bearings seem fine, so;

Any thoughts before I go spend my money on a rebore?

What oversizes are available for the 200? (2002 model if that matters)

I was surprised to find the bike has a steel liner, I had assumed it would be nickasil.

Anyhow thanks in advance, and a happy new year to all.

Hi there i know for a fact that beta barrels can not be rebored they have to be electroplated then bored to standard size there are 2 sizes of pistons for them depending on grade which is stamped on piston crown!

Thanks Betarick, mine has steel liner which I assumed would take a rebore, somebody else told me pretty much the same thing as you just did so I guess I need to phone Langcourt's in the new year.

I think from memory that the 200 is the only Beta with a steel liner, its actually a sleeved 250 barrel but this info comes from a TMX test of the first 200. I would suggest you ring lampkins not langcourt, your going to need a new piston either way from Lampkin so best get the facts first.

Thanks Baldilocks, the liner is indeed steel. For others info, I phoned Lampkins who confirmed that the earlier 200's are steel lined. Also told me that beta only do 1 oversize that I am pretty mine is already on. They did however put me onto Birketts who have found a piston that will take the bore out further, so mine is off to them in the post tomorrow. Anyhow will add a post when I get it back, the info may be useful to other 200 owners.