Heat Seized, Won't Start

[Miles]

hey everyone, I'm fairly new to two strokes and could use some help. I was riding the blaster with quite a bit of uphill, at 32:1 mix, and the engine heat seized. After cooling down it now turns freely again but wont start, also replaced spark plug. Hoping the piston is still OK but am stuck on where to go, thanks

 

[Luni]

Can you turn the engine over by your hand pretty easily? If so, your rings are done and piston might be damaged, and the bore could be borked.

Its not that hard to pull the top end off and have a look see. There are only 4 nuts that hold the jug on. Oh, I guess you gotta disconnect your exhaust, and remove your carb too.

Either way, the only way to tell is to pull that jug off and look in the cylinder. methinks you ran lean, burned your rings up, and your compression is down the drain.

 

[Kgibson]

^^^^^^ what he said plus piston could have a 4 corner seizure

 

[NEONNIGHT34609]

compression test first. if its good check your flywheel key.

 

[Luni]

Yeah, theres always that. Ive learned over the years if you push on the kickstart with your hand and it gives pretty easily, your rings are toast and the compression is low.

I had forgotten about these things tendancies to shear flywheel keys tho.

 

[Miles]

yeah it does turn over much easier now, I'm going to pull the top end apart in the next couple days and take a look, if I'm replacing the piston too is there any high performance ones you guys would recommend?

 

[Surfrjag]

Get a weisco.. consider getting it ported and head modified as well. Your going to want to take it to.a machine shop and have them measure the bore before you order anything.

 

[Luni]

I just dealt with similiar issues you have. Except I ran lean, and I actually melted my piston a bit. It was a wiesco.

I sent my jug and head off to Ken O'Connor Racing, and had him mod the head, perform a trail port, bore, hone, and match a Wiesco up to it.

I havent got it back yet, but I should be getting it soon. Considering what I had done, it didnt cost me too much. It was more than I wanted to spend, but I think it will be worth it cause I wont have to mess with it for several seasons.

Look at this as a time to upgrade some stuff and make a bit more power. The trail port and head mod is supposed to really wake this engine up a lot.

 

[N8tsNastyBlasty]

rings probably siezed in the groove or there is a hole in the piston from a lean condition. I watched my lil bro get rings out of the groove and use a needle file to clean up the grooves but i would recommend what everyone else sayz, new piston(if needed) absolutely port it if possible and a head mod. like surfjag said figure out what size u need BEFORE ordering one. I wasted a piston in 10 minutes because i took someones "word for it". I then went to h.f. and bought a set of bore gauges for under $15. I found the previous owner was a complete jack ass and my cylinder was way out of spec.

 

[Paulie B]

My guess is the extended hill climbing starved your motor of fuel- causing a lean condition.
You prolly need new rings at minimum but most likely a new piston too.
Check your float level and jetting while your at it.

 

[Miles]

Thanks alot guys, took it apart and the piston has a ''25'' on the top (definitely needs to be replaced) would that mean its a 66.25mm size?

 

[York Racing]

If you can post pictures.

 

[Racer51]

Probably fried you piston rings by starving your engine and putting a heavy load on it running it up a hill. Have the jug mesured with whats called a micrometer to see how out of bore it is to see if it needs a reconditioning or a bore and hone. good luck