Honda 2 Strokes Just Won't Die

[jetskier79]

So, as some of you might remember, a while bike a bought sort of a beater CR250. I had some great fun on the bike. But it progressively got harder and harder to start. The power was sh*t compared to some my buddies CR250 that was in much better shape. I figured, I'd do the top end eventually.

After doing the top end on my girlfriend YZ125, I figured it would be no big deal to do my, and it would be better to do sooner than later. I finally pulled the cylinder off last night, and was absolutely shocked at what I found....

Half the piston is missing. One of the skirts is broken off almost all the way up to the rings, the bottom of the piston is gouged to all hell, and the other skirt has an ENORMOUS crack running the length of the piston.

I'm obviously past just a top end at this point, because I have no idea where that half of the piston is....well, I know it's in the cases. So I'm going to pull the whole motor out and go through it.

The craziest part of all this is that, the bike RAN when I took it apart. Unbelieveable

 

[kx454]

i had something like that happen once too on a 125, i was also still surprised it was running. then i thought to my self how lucky i was that it didnt let go on the face of a jump....

 

[ANT]

Those 2-stroke 250 hondas dont like pistons for a long time. The skirt probably shot out the exhaust. Remember you can't hone that cylinder with a regular hone, you have to use an aluminum oxide 240grit hone. If its trashed and its a newer cylinder with a chrome bore then you'll have to send it out to get re-nikasil'd unless you have an older bike with a boreable cylinder.

 

[jetskier79]

then i thought to my self how lucky i was that it didnt let go on the face of a jump....

I thought the same thing. I'm glad I took it down when I did.

Those 2-stroke 250 hondas dont like pistons for a long time. The skirt probably shot out the exhaust. Remember you can't hone that cylinder with a regular hone, you have to use an aluminum oxide 240grit hone. If its trashed and its a newer cylinder with a chrome bore then you'll have to send it out to get re-nikasil'd unless you have an older bike with a boreable cylinder.

I'm going to split the cases this week sometime. My bike is a 2001. The cylinder is definitely nikasil. We'll see how it goes. It's unfortunate that I've got to spend the money on a toy that was the back up toy.....but that's life. It will be like a new bike when I'm done, so that's exciting.

 

[ANT]

i read the owner's manual of my yz250 and it said something ridiculously stupid like you have to rebuild the top-end after every 5 hours.

If you did everythiing by the manual you would have to be as rich as donald trump and have no job for more time to do maintenance on it.

 

[750SX]

If you did everythiing by the manual you would have to be as rich as donald trump and have no job for more time to do maintenance on it.

haha well said!

 

[willycrumb]

Sounds like you got a 97