Yeah...that sounds right...if the piston to cylinder clearance is too tight it would transfer more heat quicker...and obviously seize as well...


I didn't see a compression number...curious what it is and if that is part of the issue...

 

we bored it at 0.060 as its a forged piston, will try swapping the cdi box, but mine looks oem.

 

The LT50 didn't have a CDI box, I wonder if someone has fitted an LT50 exciter coil to your machine, which may be different if the LTA50 has a normal CDI system. I noted you mentioned the temp going down if you blew air onto the cylinder, if you were testing the machine when stationary, rather than right after your child has been on a run, you will get overheating, as they are meant to be cooled by the airstream as they go forwards.

 

Exactly. Stupid wiseco's swell like my belly on a good drunk night (on small cc air cooled motors). They require more clearance than a cast piston plus a very meticulous break-in.

 

Of course, that's my very opinionated opinion...

 

that could be my issue then, but zero scuffing on the piston anywhere- every time i pull it apart it looks 100% perfect. I tired a 4" USB powered PC case fan zip tied to the frame right in front of the cylinder- got me a good 5 minutes extra until it got hot. if they swell more than cast- that's gotta be it!

 

merryman, yes my 55lb kid gets tripple the riding time before it gets hot, but it still gets hot with him on it- we were camping and i was pretty wasted and forgot to have him shut it off and it stuck solid on him behind my friends house after he was on it for 15 minutes, cylinder was 409F I have the pict's but photobucket wont host them anymore.

 

I wasn't aware that you took it apart and looked at the piston. I would have expected to see a lil scuffing (or a lot).
No guarantee it's the piston being the problem but it is possible.

 

Well...is it's locking up it has to be a clearance issue...right???

 

Apparently not locking up. I've never seen a tight piston look as good as he describes.

What about the possibility of it being electrical? I know we mentioned it before but if I remember right, it wasn't looked into in depth.