My T250 has stumped me and two bike shops. I am getting spark, fuel, compression (140 psi left 150 psi right) and a leak down test shows no blown seals. My timing is spot on with the marks yest she still won't run. The shop currently working on the bike thinks the flywheel might be out of phase, but that is difficult considering that it has a key way and can only be installed one way. Please, please, please come and rescue me.
It is very common on dirt bikes to shear the key and f up the timming. They should be checking with a "Buzzer Box" and a dial indicator screwed in to the plug hole so.....
I think that is what he is doing on Monday. What needs to be replaced if that is the case? Can the key itself be replaced?
This doesn't have reed valves does it?
Nope, stock piston port.
Moparman wrote: I think that is what he is doing on Monday. What needs to be replaced if that is the case? Can the key itself be replaced?
Yes easy to do. Remove the old key and install a new one if all looks okay. If the fly wheel spun more then a few deg i'll normaly lap the flywheel to the crank to make sure the taper is good. clean crank and flywheel add a dab of valve lapping compound and work the fly wheel on the crank ~45 deg pull it off wipe clean look for high spots. Repeat as needed untill suface looks good. When done clean all the parts heat the flywheel with a 500watt halogen light. I use the light as it works slower and less damage to any magnetts ect then put new key in crack and get the hot flywheel on tight. The heat will help the taper seat tighter.
OK. The shop had another mechanic (ostensibly a two-stroke specialist) look at the bike. He ran a leak test and says that the crank seals are shot. He also said that the wrist pins came out of the right piston and the piston scored the cylinder. The bike is in otherwise good shape and I can fix the top end easily enough. The crank seals have me worried. I suppose no one here has a running T250/GT250/T350 engine for sales.
The bike has new tires, new shocks, rebuilt forks, new turn signals and a new headlight. All is done except for the engine.
Seal on that bike require you split the cases. A pain in the ass but doable and he has to remove the cyl anyway....
Never did before. Have no way to press the crank apart. No shop in the area wants to do it.
just do the two end seals leave the lab seal in the middle be unless the crank bearings are worn. the center seals are not real seals there a labirinth type basicly a wide block with groves to form chambers.
try posting on http://www.caferacer.net/index.php somone over thee will likely know who to send it too.
In reply to 44Dwarf:
OK, just got the engine back from the machine shop. I don't have a good TDC gauge so I want to set the basic timing using a test light, but I cannot remember how. I think I need to adjust the points so the light goes out just as the timing marks line up. Am I correct?
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