Greetings, I am prepping a 2012 Kawasaki KX65 for sale. It has a major non starting issue. I have checked, replaced and cleaned all the usual suspects. I have just done a pressure check on it and it is well down, she still leaks past the rings after oil has been dumped in the cylinder and re-tested, so my fianl conclusion is barrel off and a new piston and or rings. So...the question de jour is: can I get away with just a new ring set or do I need a cylinder as well. The top end rebuild was done about 5 years ago and the engine has about 100 hrs since then on it so I reckon it is overdue; I'm just trying to keep me costs low so I am sure you can guess what option I would prefer! Cheers in advance folks. BTD
Have the crank seals been replaced? Poor starting is often caused by worn crankshaft seals which are easily overlooked.
Sons 2 stroke was similar but ran rough, pressure below optimum. Check condition and you measuring the cylinder first, I put just a new piston, rings and gasket. Then a squish test on my lads Rotax 122 runs much better. I had to go up a piston size but the barrel was in very good condition, rebuild then just a few heat cycles through the engine to check for leaks. I didn't find any leaks but mine ran all be it badly, just sprayed carb cleaner on the stator side and checked the gearbox oil hadn't been burnt away.
Cheers lads. I've just ordered up a new piston, ring and seal kit. I pulled the barrel off earlier and the piston looks a bit worse for wear, may as well do it all since I took the thing apart. I don't even wat to consider main crank bearings!
If you are replacing the seals, so the primary gear and ignition has to come off, why not do the mains and have a big end / rod kit put on at the same time? Then the engine should be good for a long time for the new owner unless they do something silly.
