My R is broken...Any help??

[Yamaha Tri-Moto]

I was driving down the road on my 83R at about 3/4 throttle when all of a sudden I heard a funky noise and it died. It will not start now and it is very difficult to kick over if not impossible. I know the piston is not siezed because it will move, its just really hard. Any ideas. Any help would be great. Thanks.

[250rflattracker]

Could be a bad lower rod bearing.

[Bryan Raffa]

spun a bearing or a ring went bad

[BigGreenMachine]

Your gonna have to haul the topend off if you haven't already.

[InPiEcEs]

Your gonna have to haul the topend off if you haven't already.

Yup, I agree. You will know if there is anything wrong up top, and remember to check the wrist pin bearing.
Check for a broken ring, gummed up rings, or scoring on the piston or cylinder.
If the jetting was lean, it may have burned a hole in the piston, as well.
If all seems well up top, then it is likely a lower rod bearing, or a main bearing.
Main bearings are not too bad to change, as they are on the ends of the crank, but the rod bearing needs to be brought to a shop to be changed.
The crank has to be taken apart, and re-assembled properly.
You may get some different opinions on this, but I always broke-in my air-cooled bikes at 24:1, and then ran at 32:1, using synthetic. You can get away with a thinner mix, but I figure oil and the occasional plug is cheaper than a top-end job.

[bigred1981]

I had this happen to me on my dirt bike. It was the crank to rod bearing Seized tighter.. than you know what. Like you say I could kick it over.. but not very easy. With that particular crank the bearings were not able to be pressed out.. so.. whole new crank.. uggghhh.. well I'm sure your 83R was long before the "tin can cranks" of the CR's

[Psychotrike9]

Hope fully you didnt do what i did and spin the crank and make the rod seize up.

[Yamaha Tri-Moto]

I took the top end off today and the top of the piston has 2 tiny gouges in it as if it nicked the sparkplug, but I cant see it being from that because they don’t line up with the end of the plug at all. Also how could these little marks make it hard to kick over? I will post pics tonight. Any ideas? Thanks

[SYKO]

broke rings, and parts of the rings were flying around in the crank case some parts contacted the top of the piston and soem parts probably got stuck in the crank, complete rebuld is what your goin to need, by the sound of it

[Eric250R]

yeah....and I would probably stop trying to kick it over.....lol.....just going to do more damage.

[badasskfx]

you can drag it down the road and pop the clutch.....shell free up.....LOL

[Dirtcrasher]

I took the top end off today and the top of the piston has 2 tiny gouges in it as if it nicked the sparkplug, but I cant see it being from that because they don’t line up with the end of the plug at all. Also how could these little marks make it hard to kick over? I will post pics tonight. Any ideas? Thanks

The last 2 posts really helped out huh, Not sure what the trend of useless comments lately is other than a post whore. You guys ought to waste space in the open forum and not here where people need help. :postwhore Whats the other useless immature site?? I think it's Blaster HQ, you guys would know....


Hard to kick over is because something is not smooth and is galled or seized up somewhat. The marks in the piston could just be crap getting in the topend through the intake. Or, when the crank or con rod go bad the stroke of the piston gets longer and out of whack which can allow the piston to contact the head and other engine parts that it shouldn't.

Look for something that isn't smooth when spun by hand.

Your problem sounds like a bottom end problem - the main bearings or big end crank bearing. If your in neutral and you spin the crank by running the crank with an up and down motion - is it notchy?? If you hold the crank flywheels and try and move the connecting rod up and down - is there any play?? If not then pop the clutch cover, remove the clutch and your drive chain and start feeling the tranny bearings. If it's a bad tranny bearing then you are in luck because it's cheaper to fix then a crank gone bad - but the crank could be on the way out too. Not cheap to fix, you have to decide if a ATC that old is worth fixing for 800$ worth of motor work or better off parted and then you could grab a watercooled R. Lots of us put 2500$ into a whatever and then sell it for 1500$ so you may get lucky and grab someone elses project...

Don't forget that the tranny and all it's "stuff" gets lubricated with the gear oil. If it ran low then that could be the problem. The piston, crank, connecting rods and main bearings are ONLY lubricated with the oil you mix in the gas and if it's got alot of hours on it or a few topends without any bottom end attention then you have some work to do. Good luck.