Topic: Can I just rebore one cylinder? ( 400/4)

[neilma]

Well thanks for the comments chaps and whilst there isnt a clear consensus on the way forward, I have just ordered a set of 4 oversized pistons and will get the cylinders all bored to suit.

More money 

Cheers

[mlinder]

Best decision, in my opinion.

[Kevin400F]

How big did you go?  Your first post mentioned "deep scores"....are you certain that a .25 (first oversize) will clean it up completely?

[neilma]

Oh dear dont get me worried that I havent ordered the right size 

Ok back from a quick check in the garage and have now changed my order to the 0.5mm size instead just to be on the safe side. Fingers crossed they can ammend it before processing.

Cheers Kevin.

 

[mystic_1]

Best bet is probably to have the cylinders bored before ordering pistons and rings.

mystic_1

[neilma]

I was told they need the pistons in order to correctly size everything up and bore the cylinders to match the pistons - Is that not true (or am I mistaking it for when I asked around to get them honed instead)?

[mystic_1]

You know, I'm not sure about that.

I do know that a buddy of mine had his GL1000 bored out and then could not find oversized pistons for it (without having them custom made) so that is an issue.

If the shop doing the work says they need the pistons than I defer to their superior knowledge.

mystic_1

[MacM2010]

They probably do need the pistons--the shop did when they re-bored my 750.  If you bring them the jugs, they should be able to tell you how far overbore you'd need to go.  .5 is probably plenty, unless someone really went to town on it with a hacksaw or something.

[ttr400]

You must have the pistons first!! before you do a rebore, so they can be measured for the correct piston to bore clearance.

Kevin

[neilma]

Excellent - An end to this saga

Thanks all for your wisdom!

[mystic_1]

Good to know.

mystic_1

[Terry in Australia]

Excellent - An end to this saga

Ha ha, famous last words!