Hi again, Does anybody know what the commpression reading should be on a commpression tester for my 2005 RE. I cant find anything in the manual. Im getting ready to do my top end with a rebore,piston and little end etc and want to get some pressure figures for before and after.(i just want to play with my new commpression tester). Also im pressuming the piston is standard so what size should i have it bored to or will the workshop tell me what they end up with after removing any scores. Im hoping to start over the next few days so will put some pictures up of my barrel and piston for comments.
130 is good... anything less than 100 and it prob wont even run...
and max bore is 2mm os.. 58.5mm or something like that..
if the damage is bad it will need a new insert. then id advise sourcing another barrel and rebore it..
also I would get the barrel done at a place that will supply a piston... instead of them boring it out say 1mm then you get a piston and its not right.. at least if the place supplies the piston they wil match the bore to the piston exactly..
-- Edited by element on Tuesday 12th of January 2010 03:19:30 PM
__________________
04' DT125RE 32k miles and counting / 89' DT125R 3RN1 Rebuilt + Supermoto'd. "Those who risk nothing, do nothing, achieve nothing, become nothing"
I had a little look around and a place on ebay will do the rebore for £25,piston kit £30 and small end bearing or £5 and says he will post for £10. How does this sound. Can anyone recommend a quality piston kit.I have emailed him asking his makes but am still waiting to hear off him,i dont want cheap s**t that i will need to change again in 12 months. I hear Mitaka are a good make.
UPDATE. Finally got round to taking my barrel off today.
Things were not as bad as i thought,although i did notice it had 2 different clips,i dont know wheter it should be like this. The piston has 50 on the top,im pressuming it says.50,can somebody advise. Ive posted some pikies for any comments(DT125CRAZY)
what year bike you got? also the clips should be the same each side and if removed need to be replaced(they are called circlips), .50 is oversize i couldnt tell you what bore your on mate, you need to measure it and get piston and rings to suite,most of that barrel looks like it will clean up with 1200/wet and dry sand paper if you run your finger nail along and feel a lip like a speed bump but the oposite way if that makes sense, if its not too deep buff it out if it is rebore it ps get head skimmed while your there or do it yourself and when re fitting use only a genuine yamaha head gasket, this is because about 70% of pattern gaskets dont fit properly are warped and leak
Took the barrel to the borers today and he said it was fecked.It looked to him like there had been a seizure and alot of heat at some time indicated by the black marks down the piston and very slack in the bore,any longer it could of smashed to bits. He will remove what is needed probably 1mm. He said it will be like a new bike probably giving me back 3 or 4 HPs. Ill have to wait and see, the anticipation is killing me already.
