top end question and pipe question

[t&tracing]

just got top end rebuilt on my 98 blaster but the top end sounds like its ratteling i was tld its high compression which is good any other suggestions on wat it could be.....the quad runs strong and good so it doesnt seem like its a problem


and one more thing i have stock pipe on but no silencer the pipe ends by kick start this cant hurt the motor can it

 

[royalt67]

Insufficient backpressure probably isn't a good thing. Even straight through mufflers add some backpressure.

I would hope that the compression isn't too high, it could be detonation from low octane fuel. What fuel are you running? Also, your first thing would be to do a compression test. Kick it about 20 times or until the needle stops rising on your tester. Make sure you hold the throttle open.

 

[98blasterworked]

dont run too long without the silencer or youll warp ur head and blow the motor, thats realllllyyyyy bad, and do what royal said and do a leakdown test

 

[xJust_Causex]

You sure you got the right size piston, could be piston slap from a incorrectly sized piston, and that is bad.

 

[98blaster+4]

dont run too long without the silencer or youll warp ur head and blow the motor, thats realllllyyyyy bad, and do what royal said and do a leakdown test

a leakdown test is important but is a completely different test from the compression test. you should be running 93 octane at least even in a stock blaster. dont be cheap, just cause its more at the pump dont mean sh*t, you only need a few gallons.

 

[scotj77]

yeah man buy a silencer if you don't have one. that isn't good for your blasty.

 

[t&tracing]

i got a moto sport silencer i heard it was off a banshee but it sounds better and kinda seems like it runs better.....but i just got a compression test everything is good it has right size wiseco pistons so idk

 

[t&tracing]

i meant moto fast silencer

 

[hudack]

whats the compresion and you should get a leakdown test done also anytime you have the topend apart its a must

 

[t&tracing]

the compression is at 135

 

[hudack]

when does it rattle and what gas are you runing in it are u sure its not the reeds ticking if it does it at idle

 

[scotj77]

you prob need to be runnin atleast 91 octaine. blasters are noisy little machines but you can usually tell when a noise doesn't belong. sounds like you prob have spark knock. too low of octain. and don't think just because you used all new gaskets and torqued everything right that you don't have an airleak. no matter how precise you are you can still have an airleak. get a leakdown tester from holeshot man. stickied in the forsale pg

 

[t&tracing]

it rattles when im in like 5th and 6th ggear and or mainly when i let it wide open or just flyin down the street

 

[scotj77]

spark knock! 15151515.

 

[scotj77]

what gas are you runnin?

 

[roadkill]

yeah man buy a silencer if you don't have one. that isn't good for your blasty.

or for your ears.

 

[t&tracing]

i usually run regular in it or plus ive never ran 91 think i should start tryin and is a spark knock a bad thing

 

[scotj77]

yes very bad starts to actually blow little holes in your head and piston which create hot spots and will eventually melt the top of your piston. 91 or 93 occtain should fix that. drain that old gas out. or you could have an airleak too. you need to test that. even if the gas does seem to fix the problem

 

[t&tracing]

so better gas will stop it from doin that...so i dont have nuthin to fix.....lol srry for all the questions but im new to a blaster i traded a 2002 rm85 for a blaster and i dont think ill ever get off a blaster or go back to a dirtbike

 

[scotj77]

it should unless you have an airleak in the top end. buy one from holeshotman it is only 30 bucks and it is worth it's weight in gold. glad to add another blaster lover to the forum