250r bottom berrings

[derrik]

i'm buying my dads 86 trx but the bottom end is ratteling.

i re-build all the 2strokes top ends but ive never changed bottom end berrings.
how hard is it to do?
is it easy if a service manuel is bought?

[morse250r]

its not bad youll need a press more than likley also get 88/89 bearings theres one more ball in there then the 86/87

[derrik]

Originally Posted by morse250r

its not bad youll need a press more than likley also get 88/89 bearings theres one more ball in there then the 86/87

88 berrings? realy!?
i never knew that.

i may hve to have it done then cause i dont have a press.
i was just gonna buy the flywheel puller and go to town.

thanks for the help.

how much do you think it'll cost to get it going ?
the berrings are $40

[derrik]

i just talked to my pops and he'll buy me a press to do the berrings,
but could some one please give me a walk through?
and some advice?

[FPMXer]

If you like I can do the bottom end for you or even the whole motor. I have the press in my garage and all the necessary tools. If you have all the parts on hand I can get it done from tear down to install in about 4-6 hours. That's if there is nothing damaged inside the motor. I live in Temecula also so I'm just down the 215.

But if your dad is going to buy you a press then have at it. But the easiest way is to tear down the motor. Make sure the crank is straight, true and not out of it's service limit. If the crank is all good or you bought a new one then put the bearings and crank in the freezer for a minimum of 4 hours. Get the cases cleaned up and ready in the mean time. Install the cranks seals into the cases if they go under the bearings. Then when the crank and bearings are ready pull a bearing out one at a time and install them into the cases. Use a hand held propane torch and heat the bearing race in the case and the bearing will go in easy if it's square in the race. If it starts to bind stop and pop it right back out without damaging the seal and start over. Once the bearings are in make sure they are fully seated into the races and spin freely. Then using a brass slug or fitting set it into the bearings inner race and heat the slug with the torch. When the race starts to sweat it's ready for the crank. The crank should drop right into the bearing with little effort. Once it's in there get the transmission into the right side case and lubed up make sure all the shim's, washer's or what ever comes out goes back into the correct spot. It's very important to get the trans in right the first time. Then heat the left side inner bearing race with the same slug and either install the case gasket or yamabond onto the mating surface of the left side case. Then slip the magneto end of the crank through the bearing race and with even hand pressure push it down as far as you can with body weight. It should go on far enough to start all the case halve bolts. Then one at a time tighten them around the crank area pulling the cases together and then the rest of them pulling the case halves together evenly. Once they are together put the shift shaft into the motor and then put the shifter on and make sure the trans shifts through all the gears and you can find neutral. Also make sure the crank rotates freely. If any of it is tight and won't spin freely the cases need to come back apart.


Okay I'm done typing as it's easier for me to do it than explain it in further detail. I have a link on my laptop that I can post later that explains it in more detail. Plus for a 24 pack of Stone beer it's alot cheaper than any shop and I have done 10 smoker motors with a full rebuild and they are all still running like raped ape's. Let me know man.