250f updates

Talked to kawasaki reps today, The ignition failure problems happened to a select few, Not sure why but there saying there programing gets erased somehow, and will not allow the bike to restart,after shut down, as for our motor issue I work with a kawasaki dealer so I get the benefit of working on my own engines, so I get to see the damage first hand, the bearing in question was a quality component, {ntn} typical in all japanese dirtbikes, If there is an issue here it might be the diameter of the bearing but that would be determined by the load stress and revolution of the shaft it rides on, I'm not 100 percent sure but I beleive there was a rubber seal on the bearing closest to the case, I'm waiting for the new parts to arrive to comfirm this, Being as how the original litterally crumbled to pieces, there was a crumpled up rubber ring laying around the inside of the case, should have it up and running in the next few days, the gears and cases other wise looked great, But strangly enough the only indications we got before it happened were constant freeplay adjustment, and then nothing but freeplay, I will say this about the bike, they come with the worst stock tires We have ever encountered, We are switching to 49 tooth rear sprockets for the tracks we encounter in this area, sticking with the stock exaust sytems for now, both engines have enlarged exaust ports and then polished, with 03 kx 125 clutches and steels with kg heavy duty springs, Turn the outer fictions backward to assist in clutch drag,125 kickstarters, They are quicker and torquier than the stock bikes, we are running 1.6 radiator caps, and will be installing pro circuit water pump covers very shortly, we are running IRC VE 39 front tires and VE 33 rear tires to keep them hooked up to the ground very aggressive and tall knobbed, more to come after we had a few more races under our belts, will continue to keep you posted, These things have some extremly beefy clutch baskets on them stock.

Well got the news today, 3 items backordered, The bearing that caused the problem, the gear that it tears up next to it{2nd 14 tooth} and a seal, sound like problems to you guys measured the bearing and found an sks replacement, the only difference I see is one has 8 ball bearings in it while the stocker has 7, not sure what I want to do at this time. the fact that one has 8 balls would tell me that the Outer race is thicker which could lead one to believe it would be stronger.

called my dealer tuesday, Picked up the parts Saurday, Bike up and running again, and on the practice track sunday, I did use the aftermarket bearing on the main shaft, after I did some comparison specs between the two on line, The skf bearing was rated at 20,000 rpm while the ntn was rated at 21,000 rpm seeing as neither will ever get close to that, that was not to much of a concern, However the load force was rated higher on the skf, Bike is running great. Thanks again Rainbow Cycle, And Kawasaki.

Art you still havn't told me what you did with your exaust porting. :)

Dave Enlarge the ports and shape them more of an oval shape, Both ports are very small, and not directed out of the exaust very well, Don't try to take to much out of the top of the port there is an oil port above them, spend time blending them together as they exit, and lowering and smoothing the ports to get a straighter flow from the valve seat area, Be sure both valves are seated completly before trying this, Call me Dave If you have any questions, 417/889-2191

Thanks Art, I'll give it a try and call you if I have any questions :)

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