I have just bought a very used 02 TB. I have done a lot of repair on this bike. It is hard to start, it will not idle, and when it?s hot it is very hard to start. Throttle response is slow and compared to my 01 TB, and a little low on power. I have a small amount of gas dripping from the carburetor vent lines. Probably a bad float needle and seat. It also idles high or erratically. With the air box off I hold a ribbon of paper in front of the carburetor at low rpm?s the paper is sucked in then blown back out repeatedly, slightly higher rpm?s the paper is pushed away! Defying logic. At high rpm?s the paper is sucked in as expected. I thought the timing might be off, pulled the plug from the hole to see the timing marks and air is moving in and out just like the carburetor. Going from a low rpm to full throttle a cloud of gas comes out the air inlet of the carburetor and then sucked in. I have dissemble and cleaned the carburetor, inspected the rubber collar that goes from the carburetor to the head. New spark plug. The manual said it should have 115psi of compression. Did a compression test, it has 115 psi. Called two Polaris dealers. They both said ?bring it in we?ll have a look? (for $80 an hour). I thought it might be a bent intake valve, but this style 2 cycle has no valves. I am going to replace the crank shaft seals. The one under the flywheel must be bad. I have never broken down a two cycle and don?t know if I am on the right track? Is there a crank case vent I have missed? Cylinder wall Bad? Any thing I should look at first? Any advice would be a big help.

 

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I HAVE A 99 TB AND IT GETS RUND GREAT COLD,BUT IT GETS HOT AND STARTS PINGING AND IDLES VERY HI.I HVE CALLED LOCAL DEALER AND ALL SAY THE CRANK SEALS ARE BAD.IF I TEAR IT DOWN THEY WILL INSTALL THE SEALS FOR 1 HR LABOR 76.00 PLUSE 16.00 FOR THE SEALS

 

I bet you need a topend job.Just because you had 115psi cold doesnt mean it doesnt drop when hot.I had one act the same way and after tearing it down I found it was time for a bore out,piston and rings.Now it runs right.

 

the running eratic w/ high idle almost sounds like air is sucking in. maybe thru the crankseal. how about a leak down test to see if its leaking air, its the only safe way of doing it. i've seen it done w/ a can of either and running but dangous it can be.

 

With the flywheel and the carburetor off piston in extended. Using my air compressor set at 15 psi. I wrapped a rag around the airline and put it in the air inlet. The air came out the crank seal, as it wasn?t even there. Broke down the motor seal is shot. Lower main bearings are rough looking for a way to pull bearings off with out killing oil pump gear.

 

i bought my tb in boxes.the eng was taken apart,the head,jug and carb were off and the block was fiiled w/acorns and other nuts.i cleaned out as much as i could and had the jug boerd .40 over and put a weisco piston and ring set in it / new gaskets and intake .cleaned carb and in runs. i did not inspect the lower end,but it does not seam to make anynoise,just gets hot and starts pinging and idles real high w/ warm after about 15 minutes or 3-4 miles at about 40mph. could it be anything other than the crank seals ,oil injection works fine

 

Mine made noise when it was hot too. Pulled the engine apart, crank seal under flywheel was shot, main bearings shot, cylinder 0.007? clearance. Limit is 0.006?. a quick test for that seal is remove the timing inspection bolt. (on top of pull starter housing next to pull handle). Start bike, if the crank seal is good you will not feel any air pulsating through this hole. Will let you know if this fixes my bike. Good luck

 

hey florida,thanks for you help ..i got bored and took mine apart at work today(i am a dodge tech at a dealer) and found the seal under the fly wheel was toast(lip was torn/gone).so i replaced that side and replaced the primary side also (was not bad).had to borrow the clutch tool from a local polaris dealer.they said the clutch side is the one that always goes, but anywho it seemed to run better as soon as i started it. will have to ride about 20 minutes hard to see but i think i got it(what else could it be). i could not see the the bearing on the stater side but the one on the pto side looked visualy fine (did not take out) squirted sone 2-joke oil on it and re-assembled w/ new seal..if one had the correct fly wheel puller(stearing wheel puller works) and the clutch puller w/ air tools i was done in about a 1/2 hr maybe 45 minutes.i should have done this a year ago,but now i guess the wife gets to take her quad out too on the runs-- . maybe i sould have let it sit