Picked up a blown up blaster and I have some questions

[dirtysquared]

Id get a cometic top end gasket kit. If your getting it bored, have the shop measure the bore, then they can order the piston to the next oversize. That way its in hand and they can match the cylinder to piston tolerances. Wiseco are good pistons. There are a million crank bearing/seal sets out there. I mostly buy stuff from E-bay, Rockymountian atv, motorcycle superstore, and My friends Shop. All are good places to buy, I just spread the sales around. Hope this helps you some.

Fred

 

[dirtysquared]

Here is an excellent video series from Ken O'Conner Racing. He names most brands of parts he uses in them. Very straight forward fun to watch video's. They have helped me and others out numerous times.

http://www.blasterforum.com/engine-13/kor-engine-assembly-vids-no-crank-puller-needed-51169/

 

[Fabbed5.0]

Thanks for all of the info man


Also pretty sure I found the main cause of the piston skirt breaking, the bore is 18 thous bored over and someone put a stock piston back in it -_- So now ill be taking it to a 66.50 piston

 

[Blaaster]

18 thou over + stock piston = Uh oh.

 

[Fabbed5.0]

18 thou over + stock piston = Uh oh.

haha thats what I said. IDK what piston they used but it had to be cheap chinese sh*t, It didn't put one mark in the cylinder wall. I checked for roundness and its 2 thou out, which will be easy to clean up. all and all I feel I got pretty lucky.

 

[blastngo92]

If there's anything your gonna learn from this forum it's gonna be LEAKDOWN TEST IT
Think your engines running lean? LEAKDOWN TEST IT
Think your motors exploded? LEAKDOWN TEST IT
Think your gearing isn't right? LEAKDOWN TEST IT
Think you have the clap? LEAMDOWN TEST IT

Lol when your rebuilding the top end make sure you get a base gasket from Yamaha
Theirs are metal if you find a paper based gasket there's a chance your motor might inhale it

 

[Fabbed5.0]

haha I have gotten that from this forum. LEAK everything.

 

[dirtysquared]

 

[Fabbed5.0]

hahah .

 

[Blaaster]

I keep my 2 strokes running strong by leak testing at least twice a season.

 

[Fabbed5.0]

Ok guys I have a problem kind of. When I bought this blaster I didn't look at the Jug to well, Now I noticed it has some dimples prob from someone prying it off. I deepest dimple is 3 thou deep. Will the Copper Head gasket seal this or should I deck it. Also what about smearing a then layer of jb weld inside of the dimples then decking it with some sand paper. I would like to use this jug because I have already ported and polished it. any other suggestions will be great.

The ones closest to the bore are less then a thou deep

 

[Fabbed5.0]

Just so you guys know lol the dimples are not as big as they seem in the pics haha.

 

[harley1-5]

I wouldn't chance it I would have it decked and save a headache later

 

[Blaaster]

There is more than a fair chance that the gasket will not be able to hold in the compression, have it cleaned up.

 

[Fabbed5.0]

I wouldn't chance it I would have it decked and save a headache later

OK thanks. figured it would be the best option. Nogga have to measure the quench now to see if it is within spec.

 

[Fabbed5.0]

There is more than a fair chance that the gasket will not be able to hold in the compression, have it cleaned up.

Thanks. Worse case is its only 3 thous. How much quench does a stock motor need?

 

[Fabbed5.0]

Just a update. I got it running WOOHOOO, Fired right up the first time and idled smooth. Did the heat cycles and then tore it all back apart to paint it. Cant wait for it to be done. thanks to everyone that helped me.

 

[dirtysquared]

Glad your running. Its a good feeling you did it yourself.

 

[Blaaster]

Great, it worked.

You realise that you need to fit a new gasket and heat cycle again.

 

[Larry's Shee]

So did you deck the cyl? Do you have stock head? Not modified/rechambered? By quench, are you refering to squish? I wouldn't go less than about .045".