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Metal shavings in crankcase oil

Posted: November 13th, 2009, 10:02 pm
by 99 kittys
I just pickedup a 99 kitty for my 3 year old son and was going through it and upon draining the crankcase the oil was full of fine metal filings. It looked like metallic gray paint. The motor runs great and there doesn't appear to be any play in the shaft. Does this mean the crank bearing is going or could it be something in the governer. What makes me nervous is the governer was bypassed. Thanks

Posted: November 13th, 2009, 11:42 pm
by THX_138
Tear it down and rebuild it NOW.....

.... before you end up snapping the connecting rod or worse and having an engine that is either unrepairable or cost prohibitive to rebuild.

just my $.02 of course

Posted: November 14th, 2009, 1:50 pm
by 99 kittys
Well I just tore it apart and it was the crank bearings. They are still intact but they are on their way out. I would highly recommend against bypassing the governer without richening up the fuel mix or increasing the jet size. Had I saw the loose bolt and zip tie on the spring when I picked it up I probably would have passed on this machine or at least offered the guy less. But for $600 I guess I still did ok. Oh well time to order some parts.

Posted: November 15th, 2009, 5:46 pm
by 72
If it was one of the crank bearings, wouldnt the metal have to get past the crank seal to enter the oil in the gear case? Because you have it apart, you might want to look at some other threads about connecting rod mods or replacement. Kids grow up fast.

Posted: November 15th, 2009, 6:24 pm
by 99 kittys
That's what I thought at first. I didn't find anything wrong at all in the gear case. All of the governer pieces looked like new. I almost didn't tear it down the rest of the way. Glad I did because both crank bearings are rusty colored and feel gritty when you spin them. Also the exhaust side of the piston was scuffed up. The bearings must of been worn just enough for the filings to get past the seals. Going to look into the rod update. Thanks.

Posted: November 15th, 2009, 8:27 pm
by kidsperformance
is the lower rod discolored??

Posted: November 15th, 2009, 10:06 pm
by 99 kittys
No luckily I think I caught it just in time. The rod isn't discoloredand the bearing feels good. If I didn't decide to change the crankcase oil it would have been a disaster.

Posted: November 15th, 2009, 10:09 pm
by kidsperformance
the crank might be out of index. which could have the wobble affect going on the small gear inside the box. I've seen that happen before.

Posted: November 15th, 2009, 11:12 pm
by 99 kittys
could that cause the metal shavings in the gearbox and my crank bearings and piston problem is just a coincidence? The gears looked like they were meshing evenly.

Posted: November 16th, 2009, 1:56 pm
by 72
Look at the drive gear ( the one connected to the crank, smaller one) and see if you can notice an area of 4-8 teeth that has a wider or offset wear pattern. It might be subtle, this is what kidsperformance is talking about and yes this could cause what you found in the oil. Crank bearings being tan color is more common than not (its a fuel and oil related) , I say have the crank alignment checked and change the bearings and seals because you dont know the history of the machine (its ten years old) but mostly because you have it apart. 2-cycles tearing up the area around the exaust port is the result of their design, garbage ends up being pushed back and forth and sometimes it sticks.

Posted: November 16th, 2009, 5:20 pm
by 99 kittys
Thanks for all the help. I took a good look at the small gear and sure enough about 1/3 of the gear is only worn 20% of the way across the rest is worn 90% of the way across. I would of just contributed everything to the bearings and put it back together.

Next question is where is the best place to get the crank trued and maybe get the updated rod while its apart. I think I remember where I had my Yamaha Banshee crank done years ago when I was racing but not sure about these little guys.

Thanks,
Bill

Posted: November 17th, 2009, 3:12 pm
by kidsperformance
I do them...pm me