something got ugly

[dan_mihm]

back in august i was out on a ride on the cr. all of a sudden i got a weird bogging, like it was loaded up. i clutched it and it shut off. i kicked it over, and there was no compression. i'm getting ready to pull the head off and have a look, but does anybody have an idea what may have happend? and also, it was re-built in feb. 2009



thanks,

dan

 

[Ol'89r]

Sounds like you may have seized something.

Go ahead and pull the top end.

 

[dan_mihm]

it kicks over freely. when you say seized are you talking about the rings? everything is kinda pointing to hole in the piston

 

[Scotty99983]

it sounds very like your rings have gone. or as you say you may have holed the piston. only way to find out for sure is strip the top end down

 

[Ol'89r]

The bogging indicates a piston seizure. When the piston seizes it will transfer aluminum from the piston to the cylinder. When that happens, you lose the seal on your piston rings. It usually scratches up the cylinder wall also resulting in even less compression.

Just take it apart. It should be obvious when you get the top end off.

 

[1998RM250]

I wonder if this is happening in my bike? Mines been bogging like crazy, but I just replaced the rings. Maybe I should have replaced the piston as well?

 

[rmc_olderthandirt]

It isn't something that keeps happening. When it seizes it feels like it is bogging for a few seconds and then it stops running. And then it is very unlikely to restart.

Sometimes it seizes to the extent that the piston locks in the cylinder, which can be very interesting if you were going 60 MPH when it happens. More often it seizes for a second, transfers aluminum and gouges the cylinder, and then the motor spins freely.

It doesn't really matter, if you have lost compression you need to tear it apart.

Rod

 

[1998RM250]

what causes seizures like this besides worn out rings?

 

[smahala1286]

Riding wide open on a road or trail at high speed and rolling off the throttle with it still in gear. That usually will cause a seizure in the lower end like the large rod bearing though.

 

[dan_mihm]

i think over my x-mas time off from work im going to rip into it. its been bow season here since it happend, and then rifle season came in so my mind is elsewhere. but now im kinda thinking about it again

 

[rmc_olderthandirt]

what causes seizures like this besides worn out rings?

Running too lean

Running out of water in the radiator

Over reving

not enough oil

poor grade of oil

dirt getting past the air filter

too low of octane gas

it wasn't put together properly last time (ring end gap, failed to drill oil holes for exhaust bridge, etc.)

And I am sure there are other reasons


Rod

 

[whenfoxforks-ruled]

If the engine was detonating it may not seize till its too late. That is how you get a hole in the piston. Its not like its a 4 stroke, check the plug frequently. Doing a top end job without having the bore checked for being true, complete waste of time and a real headache to except failure. Check the crank thoughly while you are down there. At that point, 3 to 400 dollars and you can rebuild the whole motor! Like the iffy seals, main bearings and crank. Do not forget the reeds and packing. Few things are as sweet as a fresh engine. And keep track of the hours on the new engine. Vintage Bob

 

[dan_mihm]

well, i pulled the head ogff and this is what i found: ring or clip blew apasrt and destryoed the cyclinder..........hellllllooooooooooooooo bank

 

[whenfoxforks-ruled]

300 or so for the big bore work, he supplies the hard goods at a reasonable rate, and have him throw in a bottom end kit for a few hundred more. You will have a new engine that you know everything about. And get an hour meter also, under twenty bucks. Send it to Forward Motion, with the entire clean top end. Vintage Bob

 

[jcroley]

Funny, this just happened to me!, you blew it up!, mine did the same bogged then no compression, broke a ring and junked the cylinder. Found broken rings in the pipe. Good luck!

 

[jcroley]

eric gorr is the best in the bizz, ship it off and big bore it, 500 bucks, new cylinder, piston rings costs more than that!