well i just blew my blaster up and now wanting to know whats the best piston ?
- Thread starter thekingblaster
- Start date
i run only wiseco's, but they require religious warm ups.
the vertex and namura cast pistons are decent also and do not "swell" as much as a forged wiseco, but break skirts easier and grenade into a thousand pieces when they do.
if you're in doubt of allowing it to warm up completely...before, and even during every ride if allowed to cool down, go with a cast piston.
as for gaskets...only OEM yamaha or cometic base gaskets,
avoid the paper ones, i've seen green, blue and black
the vertex and namura cast pistons are decent also and do not "swell" as much as a forged wiseco, but break skirts easier and grenade into a thousand pieces when they do.
if you're in doubt of allowing it to warm up completely...before, and even during every ride if allowed to cool down, go with a cast piston.
as for gaskets...only OEM yamaha or cometic base gaskets,
avoid the paper ones, i've seen green, blue and black
Sounds like a good time for a fresh rebuild.lol Wiseco pistons and Oem gaskets or Cometic only for me also.The question is why did it blow? Hopefully something in the lower didn't cause it.
Well it stalled in the trails so i was going back to the cabin and and i got it back then i started it when ten feet and motor locked up ? Running 32:1 ive never heard of this have you and i have yet to take it.apart yet im just so busy mowing yards
You are going to have to atleast take the top end off and see what is going on.Alot can happen.Alot of times the crank can take the top end out.Time to pull it apart and inspect it.
You might have to do alot to the motor in general.Or you may not have to do much.You will not know anything until it is inspected.If the piston shattered,broke,etc the pieces can and will go straight into the lower end.Best thing to do is take the top end off and inspect it.You will know as soon as it comes off.
So here you guys go i did a leak down test and it wouldnt even hold 30 psi so i ripped it apart saw a ring just chilling on the jug lol View attachment 7584
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Your not supposed to use more then 6 psi when doing a leak down test ! It is VERY likely you blew out your oil seal(s) on the left ( stator/flywheel ) side, right ( clutch ) side or both.
Judging by that picture your cylinder bore/walls have to be scraped and gouged like crazy ! Even after you get it bored, honed, and fitted with new piston/rings you HAVE TO find out what caused that destruction before you even think of starting that motor again. It appears you may have just had too much piston to cylinder clearance, or some bad port work that caused them rings to stick/catch like that !
If it would not hold pressure I would bet that the problem was caused by a lean mix eventually causing the top ring to be pinched into the exhaust port.
Could you post a pic of the piston crown favouring the exhaust side?
Could you post a pic of the piston crown favouring the exhaust side?
Ok im new to all this and i used the tester that screws into the spark plug hole idek my dad did all this when i wasnt home but not that much scoring on the jug. So dont qoute me on that thats just what i was told
A leak test is different than a compression test. You should never use more than 6 psi when leak testing! I'm guessing you had around 30 pounds of compression????
I wil try my best to and ill post pics of the head to and that will show you guys that this thing needs to be jetted
I just asked him and yes he did a compression test and one of the wirrdest ones i know of like you screw thing in head then pump up with bike pump so you dont have to kick it to get compression
Ok so i did find out what caused it, there are pinss to wear the Rings can't slide around and the one top pin for the top ring broke out and then its like the rain go round and round and that's what caused it to get caught on exhaust portView attachment 7589
View attachment 7590
View attachment 7590
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Ring migration will do it every time.
When you fit the new top end, do a leak test before you start it up.
When you fit the new top end, do a leak test before you start it up.
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