81 or 82 250r woot!

[jeffatc250r]

Did the crank bearing let go. Is the crank loose? Those gouges look like they were caused by chunks,......

[Lukeatc185]

if you only had 120lbs of compression. it was on its way out to begin with. should of been upwards over 160psi

[jeffatc250r]

Compression according to the honda manual calls for 142-165 warm. Also the heavy smoking and bogging could be from a bad crank seal letting in tranny oil,.....

[Dammit!]

What size jet was in the blaster? That piston looks like it was run lean. Far from the worst I've ever seen but looking around the edges, it got hot in there.

[mohadib]

I was wondering the same thing Damnit. I'll get out there and check the crank and jet size in a minute lol. All that kicking, once the piston/rings gave out, wore me slap out! What do you see on the piston that lets you know it was running lean? Thanks!

Edit: I checked the crank. It seems fine to me. The jet in the carb is hard to make out , but I think it says 100 on it. Does that sound right? I found two burs on the sleeve where my two biggest gouges are. Also, on the front side of the piston I noticed it has no groves at all around the top. The back side does. Is this normal wear? Thanks

[Dammit!]

I was wondering the same thing Damnit. I'll get out there and check the crank and jet size in a minute lol. All that kicking, once the piston/rings gave out, wore me slap out! What do you see on the piston that lets you know it was running lean? Thanks!

You can't just throw a random jet in there man. Guaranteed that blaster jet was too small. Too small of a main jet is the fastest way to ruin the top end (as you just found out, d'oh!). You can tell it was lean by the color of the piston. White is bad. That means HOT and you can see it was starting burn the edges away. I've got a 250r in the garage that I basically got for free because it was run so lean it burned a hole right through the piston.

There's a jetting sticky in the help section.

[jeffatc250r]

In my findings over the years, a lean condition will generally melt the exhaust side of the piston as it is the hottest. From that pic, with the gouges on the intake side, i think its a mechanical failure, could also be from eating crud from no air filter. Im sure the 100 main didnt help things out either. Not saying your wrong by any means. The cards are stacked against this thing with the blaster carb with the dinky main and no air filter. Heres the result of a too lean condition. The top part of the piston actually melted on the exhaust side.

[mohadib]

Thanks everyone. Feel kind of like a 'tard about now. But that seems to be my learning style, breaking stuff then fix it I'll get the proper carb, stock jets, new piston and rings. If there are any light gouges at all on the sleeve should i have it bored a bit (if possible)?

[Dammit!]

Stock jets aren't always the right jets. If anything has been changed that increases or restricts the airflow through the engine, the stock jetting will be off. Elevation and even humidity can play a factor too. Stock can be a good place to start but if you're running an open airbox or anything like that, you'll need to be richer. Spend some time reading up on the subject. Once you understand it, jetting is easy and will insure you're able to tune your machine correctly.

[RodKnockRacing]

hell my buddys piston shattered in the cylinder and the pieces jammed in the crank

[harryredtrike]

Check the compression of course. But also check the exhaust port for excessive carbon deposits. Sometimes you have to clean them out and sometimes you have to de carbon the top of the cylinder. Also, If your exhaust pipe is all gummed up it will restrict performance. Make sure your airfiler is clean. Looks like a great start to a fun project. I love the fat tire 2 strokes.

i agree,get right fuel mix with good fresh gas,clean out exhaust silencer with new plug and see.should be good,also make sure you reset the mix and idle screws to factory,manual on this forum,use the search above to find.