Mac
Member
Guys I have a question about piston to cylinder clearance. The reason I ask is because of the taper on the pistons from Wiseco. My pistons are the 72.90mm 780 big bore. The top of the piston just below the bottom ring is 2.864 and at the bottom 2.871. I was planning for .003 clearance between the piston skirt at the bottom of the stroke. Does .010 thou sound correct at the top? Ideally what would be desired?
JERSEYJOE
Member
Piston clearance
If sled motors are like most motors the piston clearance is measured on the skirt halfway between the bottom of the ring groove and the bottom of the skirt. Pistons are not round they are eliptical for starters and they do measure smaller toward the piston dome due to the increase heat ( more expansion).
Mac you are just like me. I have a new APEX GT but I REFUSE to let my SRX go. In my opinion the SRX is a better sled for the HILL, but for the touring that you and I like to do, the 4 stroke is much better. Remember that place in Quebec where the lady made the two stroke rider remove their clothes before entering her place?????
If sled motors are like most motors the piston clearance is measured on the skirt halfway between the bottom of the ring groove and the bottom of the skirt. Pistons are not round they are eliptical for starters and they do measure smaller toward the piston dome due to the increase heat ( more expansion).
Mac you are just like me. I have a new APEX GT but I REFUSE to let my SRX go. In my opinion the SRX is a better sled for the HILL, but for the touring that you and I like to do, the 4 stroke is much better. Remember that place in Quebec where the lady made the two stroke rider remove their clothes before entering her place?????
Mac
Member
Joe I'm asking a serious question here - and you gota poke fun at my piece of SHIT Viper 780 LOL. Guys its true this lady way up north in Quebec would make us take off our smelly two smoke clothing before entering her B&B. We could have made a Yamaha Johnny sceptial video. I am happy to report I snowchecked new Nytro MTX only it has not been delivered to NJ yet. If I want to go real fast I still need to fix my 780.
So does .010 thousanths sound correct up top?
So does .010 thousanths sound correct up top?
vibeline
New member
piston measurment.
Measure the piston 3/8 up from the bottom of the skirt
.010 small at the top is normal.
.003 sounds a little tight for wisqueako's
Measure the piston 3/8 up from the bottom of the skirt
.010 small at the top is normal.
.003 sounds a little tight for wisqueako's
JERSEYJOE
Member
Serious
Serious You Have Minimum Clearance At .003 In The Center Of The Skirt. Wiseguys Like About .005 Clearance. When Are We Doing Lunch? Lonestar????????
Serious You Have Minimum Clearance At .003 In The Center Of The Skirt. Wiseguys Like About .005 Clearance. When Are We Doing Lunch? Lonestar????????