Engine trouble

[Gagesblaster]

Just picked up another blaster...not sure the year....only thing wrong was the rings destroyed the piston....dude said it was bored over....i didnt have a micrometer to find out size so i ordered a stock piston because i had a stock top....bike fires right up idles good....but its sputters until i get the rpms up....cannot figure it out

 

[Awk08]

whats the compression of this new top end ?
did you do the heat cycles then re-torque the head/base bolts ?
check for airleaks with a leakdown test, as all new build should be
clean the carb ?
just for starters

 

[Slydog]

What was the numbers on top of old piston
? Ussualy will have piston size engraved on top. (66.00) example for stock bore piston

 

[Gagesblaster]

What was the numbers on top of old piston
? Ussualy will have piston size engraved on top. (66.00) example for stock bore piston

573m06675 was old piston numbers

 

[Gagesblaster]

whats the compression of this new top end ?
did you do the heat cycles then re-torque the head/base bolts ?
check for airleaks with a leakdown test, as all new build should be
clean the carb ?
just for starters

My buddy let me borrow one of the gauges to check it....took it for an actual ride today and retightened once i got home and ive cleaned carb....looks brand new....once u get the rpms up it runs like a beast....but 5th and 6th gear doesnt run the best

 

[Slydog]

573m06675 was old piston numbers

So bore is 66.75mm. Last 4 digits is piston size ussualy on these pistons.what size did you put in?

 

[Slydog]

My buddy let me borrow one of the gauges to check it....took it for an actual ride today and retightened once i got home and ive cleaned carb....looks brand new....once u get the rpms up it runs like a beast....but 5th and 6th gear doesnt run the best

What were the jet numbers in carb?

 

[Slydog]

Also check air cleaner. Float height could be off.do plug chops to confirm jetting is very important.so this piston doesn't fry!!what carb is on it.is it the stock carb?

 

[Gagesblaster]

So bore is 66.75mm. Last 4 digits is piston size ussualy on these pistons.what size did you put in?

Stock size because i had a couple stock jugs...and its a stock carb needle and jets...i took insides of of my other blasters carb

 

[Slydog]

Stock size because i had a couple stock jugs...and its a stock carb needle and jets...i took insides of of my other blasters carb

What's the numbers on the jets.leakdown test?as mentioned earlier.there is usually a reason That piston looked like it did.what clip position is needle on in carb. Usually middle position works on most stock carbs