cheap engine mods????

jrfan

jrfan

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Joined
Dec 19, 2008
Messages
51
Location
Saskatoon Saskatchewan Canada
popped a piston in my 98 vmax 600 twin today, sled has 8300km on it so I figure we will just rebuild it for safety sake, and cheap mods one can due to this engine to pull a little more HP? while keeping the Yamaha reliability, sled is bone stock, motor never has been opened up.


thanks in advance!!
 
Thought so, looked like a big guy on your avatar! Sorry to hear that you blew it up. The way you said that thing went, I don't know if I would do anything to it. If you can lift the skis off when you launch with a guy your size on it, I'd say that it was set up pretty good. You know what they say... if its not broken, don't fix it! Good luck.
 
you saying I am big....... :wink: I think your right, last weekend on hard packed I was still spanking my cousin's 700 his brothers 583 and my buddy's 670, for a little 600 with a 400 lb dude on it it moves pretty good,lol
too bad it popped!
Just rebuild it and keep it simple, had it out to my mechanic a few weeks back and he took her for a spin...well his reaction was, quote: when you said that thing would pull the skis, I didn't think you meant that hard and that high lol

It has been such a reliable sled for a ol girl! can't ditch it........must rebuild it!!
 
need to find out why the piston popped in the first place, or else you'll be back to square 1 again. on the 600 twin, a thin head gasket, reed spacers, and carbon tech petals can help it out some. porting would be the next thing. porting is a cheap hp increase, if you can do it yourself.... :wink:
 
Look up the reed stop notch in the tech pages. If you got that many happy KMs out of it stock, why mess with it now. Maxdlx
 
thank's for the input guys, looks like the skirt broke off and took out the cyl, decided to keep it stock.....well might just do the thin head gasket ;)! so now I am looking for some cyl........
 
Cheap thats all relative, I had to redo my 97 XTC 600 cause of low compression 85 psi @ best, I sent my upper half out to Hauke, Pat told me I was lucky it didn't break a piston skirt and to fix it now, They inspected and measured tolerances and prepared it for me to be put back together(Perfectly) Everything in my case turned out well now it has 125 to 130 psi on both, I had the superceded pistons already which helped save, Had to have superceded rings and I had extreme oil consumption that I fixed with a updated new oil pump, Oil usage normal now, Thing is I went with the .06 head gasket, Head to piston is now 73 thousants (92 octane only) Plus I jetted down 1 size and me and the sled get parked if temp drops below 0 F, These things made such a difference, Now I'm still working on fighting a (Slight) over rev even with 1 tooth taller gearing even (24/39) and Turks clutch setup, My clutching 50/44 Micro Belmont helix, Green spring @ 70 rap, Stock pink(I beleive)primary spring 8AB weights with heaviest rivots in both holes on weights, 89L belt, I have over 1500 miles on it so far and it loves it just need to tweak it still, Have no other mods, My weight is 160 lbs, If a 98 has the pipe rear heat exchanger get rid of it and get a real one off of a 700, Going a little off topic, I changed my joint stabelizers, They're off of a sxr they're stiffer and I changed my center spring(Pioneer performance's stiffest) Do to how much U weight I'm sure it would help U out, These suspention changes do add dartyness @ slower speeds but when U get up on the wheel and attack it's awesome, I sometimes get to lead a nytro and a RX 1 and the tighter and rougher the trail gets the better, Consider getting shocks rebuilt for your weight and riding style. Sorry for the long post, Just trying to help
 
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