blew top end!!!!

[Dirt Addict]

my 1st ride on my new to me 2006 ec250. about 2 hours into it poof. engine shuts off while climbing a hill. after getting the bike turned around on the trail, i kick it over. no compression / wont fire up.
prior to riding it i checked the jetting. its supposed to have a ltr jet kit in it. 175mj, needle in 2nd pos. i think a 48pj.
temps were 75 -80 f. elev. - 4000' - 6500' asl. 40:1 motorex syn.
what happened?
it did seem rich off idle and lean up in the rpms....
so where do i get a top end kit from?
i will open it up this week to see what the damge is...

[iajim]

Sounds like you've burned a hole in the piston. Usually this is caused by ignition timing being too far advanced or old/ stale gas( pre-ignition, not always the same as detonation). Detonation is usually caused by low octane, not bad enough to cause a meltdown, but sooner or later it would cause trouble. Pre-ignition can be caused by old gas, low octane + low/ no vapor pressure. It could also be caused by a hot spot on the head or piston. Think of a chisel mark instead of a smooth surface. If you have score or siezure marks on the side of the piston that would indicate jetting trouble. After you tear it down, let us know what you've found.

[slocalspode]

Damn, that sux. Please let us know what it looks like
once you get it torn down. I'd be curious too.
Depending on where in So. Cal. you live. There is a
real GasGas guru not too far away. Check with
Steve and MotoWest. If there is any confusion on
why your motor failed. He can diagnose it for you.
As always, GoFasters for your parts, but, Steve can
also get them for you. I have also have had great service
from Bob @ NorthTahoe motorsports.
Sorry for all the plugs in one post. These are just great
people to do business with. Good luck.
Jeff So. Cal.

[Dirt Addict]

ok i got it opened up. there is a 5mm hole in the piston. ughh. im looking for my camera to take pics now...... more to follow.

[jostby]

Originally Posted by Dirt Addict

temps were 75 -80 celsius.

in Socal??

Sucks about the hole in the piston though. Slocalspode is correct on the dealers though. Read other posts... don't let just anyone hack on your engine if you aren't going to do it yourself.

[Dirt Addict]

oops i meant farenheit. fixed it.

well the cylinder looks good. still has the cross hatches, no scoring. the head got roughed up on an edge, i think i can smooth it out with some fine grain wet sanding.

[Dirt Addict]

well i just ordered a piston kit from gofasters. $200+ !!
dang gina. im used to 130. for my jap bikes.
oh well, im looking forward to getting this bike back on the trail...
thanks to everyone for the help. more ??'s to follow im sure.

[AZRickD]

That sounds rich to me.

Check the jetting thread stickied on the Carb forum.

Heck, I'm in Phx with 90F, 1200 MSL, with MJ=172 and PJ=42. I've been running it like that for nearly two years. Leaner in the summer and a tad (178/45) richer in the winter when it gets all the way down to 60F.

Plug looks Snickers brown.

I've just gotten the RB-Designs squish band mod so I might not go that rich in the summer.

[Dirt Addict]

definitely wasnt rich. plug was white. the previous owner told me it had a ltr jet kit. the needle was a ddk. he said he was having trouble with spooge and was trying to lean it out.
i put the oem needle 2nd clip, back in and went to a 180 mj. when i get the parts in i will work on fine tuning it.

[jostby]

I run LTR kit on my '00. 48 pilot (as recommended by Les) and 180 main (he sent a 175 but I like the 180 better). My kids bike is 46 pj and 180 also.