It shut off , lost compression

[JACK STRAW]

'08 400ex was running strong then shut off. Compression was 60 lbs. I put 2 squirts of oil in the cylinder and it jumped up to 155 lbs and every other engine I have done this on will burn the oil off within a minute or two of restarting, but this one is now holding 155 lbs. I put the plug back in it and it started right up , smoked for about 2-3 seconds, then I rode it for about 5 minutes. Checked compression again and I am at 155 lbs. Ran it another 15 minutes and checked and still at 155 lbs and it pulls great in every gear and does not smoke a bit. Engine has about 250 hours and has been serviced regularly thru its life. What am I missing.I don't want this to "grenade" so where should I go next. My 15 yr old thanks in advance.

[400man]

sounds like it tried to sieze up but the oil broke it loose. i had a bike do that to me and after it un seized it smoked really bad so i put a new piston and rings in it. yours might be fine if it doesnt smoke? although i wouldnt trust it under heavy riding. might be best to pull the head and see what the cylinder looks like,

[JACK STRAW]

I started it up tonight and it popped right off without a hint of smoke. We let it warm up and they took off for about 20 minutes running around the fields. no smoke at all. I think I should pull the piston, but the other half of me want to run it as is

[400man]

oh, well you know the saying, "if it aint broke, dont fix it", this might be one of those times to follow it. might as well ride it, just keep the oil checked,

[DragonGunner]

Do a oil change and run the dog crap out of it...its a Honda.

[Blodg]

I agree with the advice to run it...

[JACK STRAW]

he has been running the crap out of it until the carrier bearings blew apart today. now i found out more info. him and his friends swamped the quads a couple of weeks ago,so i guess he sucked something muddy in.