holygoat
Site Supporter
- Location
- Indiana, USA
What do we think went wrong? I think he just had a hone on a scored cylinder and put stock bores pistons back in there, so I'm assuming a cyl might have caught a piston ring.
Last edited:
Friend's brand new 750 build. One ride. I think his bores are a bit loose?
- Thread starter holygoat
- Start date
What do we think went wrong? I think he just had a hone on a scored cylinder and put stock bores pistons back in there, so I'm assuming a cyl might have caught a piston ring.
- Location
- Michigan
Double OUCH !!
- Location
- Charlotte, NC
This is exactly why you have to actually measure the bore after honing to make sure it's not too loose. Had to be super loose in order do that on the first ride after the build.
Myself
manic mechanic
- Location
- Twin Lakes AR
Since those appear to be pieces of a piston skirt.......I'd guess the bore is so loose that the piston skirt was slapping back and forth until it cracked. Then the bits start breaking down and spitting up through the ports. Lower rod bearing and adjacent crank bearings are probably toast now as well.
- Location
- Dalhart, TX
Anytime I have any scoring on a cylinder or piston that can catch a fingernail, I always go up a bore size and new pistons. It might not always be necessary, but it’s A lot cheaper to spend the money on machining and new pistons than replacing the whole engine
holygoat
Site Supporter
- Location
- Indiana, USA
Agree to all of the above. As soon as he told me he just threw stock bore pistons in a hone my face dropped!
WFO Speedracer
A lifetime ban is like a lifetime warranty !
- Location
- Alabama
There is never time to do the job right but there is always time to do it over.