OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Two Stroke Trimmers & Brushcutters Kawasaki TG20

My nans next door neighbour gave me this Kawasaki TG20 straight shaft that he couldn't get to work, which is good for me because i have always wanted a straight shaft. I pulled it down and found the crank stuck solid, i have got some small movements out of it but i think its been sitting for that long its decided to call it quits.

The internals are still in good clean condition apart from this problem and was just wondering if the bearings are servicable or throw away items?

Cheers

Josh

hi josh,
being a kawasaki it is likely to have replaceable bearings.if the bearings have rusted or seised due to heat related malfunctions then its best to replace them, but if they have just became tight over time then i normally fill the sump up with diesel and let it soak. the diesel works good when it come to un-seizing things. if you let it soak for a few days, and slowly tap it free with a hammer it should be right to go. this method works good on most engines that have seised due to sitting a long time. if they do become free make sure they have the right tolerances and are not loose before starting the engine as this can cause damage.
regards jay

Jay, I would do a bit of filtering before I tried to rescusitate seized ballraces that have to run at engine speed. If they are just stuck with hardened goo (oxidised oil) I agree with your plan. If they show any signs of brown rust on the track sections of the inner or outer rings, I think it's best to put them straight in the skip. Any roughness on the track at high speed will cause chipping and track erosion - and if there is rust, there is roughness.
It is often a different story with bearings that will only run at low speed and light load, of course.

It now spins freely but i accidentally damaged the piston skirt so i will need to get another

hi josh,
how did you free the bearings and what do you think seized them in the first place?
regards jay

I think it was lack of use, i could see the bearings and they wern't rusty at all maybe just a build up of gunk, i tried to spin the crank and it started to spin freely now, just need to get another piston as i dont think using a piston with a damaged skirt would be a good idea somehow!

Depends how much damage and where it is. On a 4 stroke you could deal with a minor dent or nick by smoothing it across with a file. On a 2 stroke like yours it depends on whether the missing material would affect the port timing.

The skirt is buggered both sides, i've taken the exhaust off and can see that with the piston all the way at the top the underside ( where the skirt should be ) is exposed

I'm not clear on what you mean here. There is one section of the bottom edge of the piston that runs past the intake port when it is at the top of the stroke. If that section has been damaged, it won't open and close the port cleanly and the engine may not run as well as usual due to having the wrong port timing. For the other three quarters of the piston's circumference, it is only important to have a good fit so that the piston can't wobble, or scratch against the bore. Are you saying that when the piston is at the top of the stroke, the bottom of the piston is going past the exhaust port? You'd have pretty serious damage for that to happen. The engine can't run properly, and may not run at all, if the exhaust port is partly open to the crankcase at the top of the stroke.

Yeah the Skirt of the piston broke off

You definitely need a replacement piston. I thought you might have just nicked the bottom edge, and needed to debur it with a file.