beta boy Posted April 4, 2005 Report Share Posted April 4, 2005 my techno has started rattling recently im gonna sort that out but at the same time what else should i do, i dont think it has ever had a rebore the previous ownere certainly didn't neither did the second cause ive spoken to him and the origional owner on the reg document i no and he replaces his bikes very often. do you think it needs a rebore or just a new piston and rings. should i do the mains and the big end. do i have to send the crank somewhere to have the bigend done or can i do it myself any sugestions would be great Quote Link to comment Share on other sites More sharing options...
beta boy Posted April 5, 2005 Author Report Share Posted April 5, 2005 ive allready found out about oversize pistons for the beta they are easily avaliable, and apart from the rebore the work will be done by my dad and he's paying for it as he is two tight to get me a better bike and i have no trouble doing sections on my bike. Quote Link to comment Share on other sites More sharing options...
gasgas Posted April 5, 2005 Report Share Posted April 5, 2005 (edited) i have some more info about the nikasil cilinders. First you can not rebore a nikasil cilinder in the old fashion way like iron sleeved cilinders as the nikasil plating is only 100 micron thick, 0,1mm. You can however hone a nikasil cilinder in order to get it round again with a nice fresh crosshatch liner, in which case you buy an oversize piston in order of 0,01mm. The famous a, b, c, d, and perhaps e pistons. The difference in diameters is 0,05mm from the a till the e piston. Deep scratches in the nikasil ask for replating. They first chemically remove and bore out the old nikasil. Weld the scratch in the cilinder, bore it again, and finish with a new plating which is then rehoned to specs. ps: i think the Techno has a nikasil cilinder also, and that yr oversize piston is just a b or c type, specially made for nikasil cilinders. If so, i wld recommend to fresh up yr cilinder with a hone and measure the inside of the cilinder for roundness and get the right oversize if you can. Edited April 5, 2005 by gasgas Quote Link to comment Share on other sites More sharing options...
beta boy Posted April 5, 2005 Author Report Share Posted April 5, 2005 it is nikasil, and thats what im talkin about gasgas hoe it done how much does it cost to have that done it has no scores in it or flaking of the nikasil but it has lost compresion sice i first got it. does that mean i just need new rings Quote Link to comment Share on other sites More sharing options...
gasgas Posted April 5, 2005 Report Share Posted April 5, 2005 Can you still see the crosshatch in the cilinder. If so, it will mean that the cilinder itself is fine. Normally the crosshatch first will disappear at the pressure side of the cilinder(this is the intake side) and when it is still there things look promising. When the cilinder/piston clearence is still within the specifications, rings cld be enough to think of. Loss of compression can also mean a leak in the carterside of engine. So there is loss of intake mixture. Pressure/leak down test wld give an answer there. About costs i don't know as i live in holland, but here replating comes at 150 euros. But offcourse then you also need a new piston and labour etc. Quote Link to comment Share on other sites More sharing options...
beta boy Posted April 5, 2005 Author Report Share Posted April 5, 2005 whats the carter side of the engine. ill give you a list of things that have been done recently to the engine. new rubber boot from airbox to carb new inlet manifold gaskets and stuff new reeds as one of them had a corner mising new crankcase gasket aswell cause the otherone use to leak oil. also had a new base gasjet on the cylinder Quote Link to comment Share on other sites More sharing options...
gasgas Posted April 6, 2005 Report Share Posted April 6, 2005 (edited) "carterside of the engine" is probably wrong english. The air/fuel mixture is flowing via the carter where the crank is located to the cilinderhead. So if a leak shld occur in the carter/ between the case joints pressure is lost. One of the reasons why you shld be carefull with splitting the cases. But to come back on the original question of you: what else shld i do? I can say, when you have found the rattle... and it is only worn rings leave the rest. You have no other problems then this rattle, correct? When it is a bigend problem, you have to split the cases, you can check all the inner stuff without a hassle. Edited April 6, 2005 by gasgas Quote Link to comment Share on other sites More sharing options...
james111089 Posted April 6, 2005 Report Share Posted April 6, 2005 new rubber boot from airbox to carb new inlet manifold gaskets and stuff new reeds as one of them had a corner mising new crankcase gasket aswell cause the otherone use to leak oil. also had a new base gasjet on the cylinder If that part of the reed has got sucked into the engine that will not have done the piston or bore any good, maybe causing you to lose compression There might be some nasty scrapes done your bore. James Quote Link to comment Share on other sites More sharing options...
james111089 Posted April 6, 2005 Report Share Posted April 6, 2005 just seen your post further up saying you have no scores etc. I would just replace the rings and the little end while youve got the top off. Rings are the cheaper option so i would try that first. James Quote Link to comment Share on other sites More sharing options...
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