km 130 melting gear and valves not lubricating

daveinluray

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Hi
First post so thanks for having me.
I am a homeowner that trys to do myself what I can, unfortunately my 4 mix is giving a fit. I was unsure which repair forum to use so have started here. I hope that is OK.
After sitting for a few years I have decide to try and salvage my Kombi syatem.
I have replaced the piston, bearings and seals. I used valve compound on valves(first time so unsure of success). Everything appears straight and in order and engine runs fine at first but the cam and valves are not lubricating which melts the gear.
My carb does need to be rebuilt but i wanted to wait until I resolve my lubrication issue.
I use opti 2 but even tried conventional oil at 50:1.
The muffler and spark arrestor are clear.
I cant help but think Ive made some sort of goof on reinstall but have tried to use good resources as an aid.
My thoughts are that maybe a valve is not sealing causing the flow of fuel to not go through crankcase? im just not sure, but sure could use some advice.

Thanks
David
 
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Rivets

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When you used valve grinding compound on the valves, did you make extra,extra, extra sure that you clean the valves, valve seats and all other surfaces very well? Valve grinding compound is an abrasive and any left over will cause wear and clogging problems. Any time it is used you must make sure everything is very clean, with NO residue. Also; a lean mixture will cause overheating, which may look like lack of lubrication.
 

daveinluray

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yes very clean. mixture is good and i changed up from Opti 2 to a conventional 50:1. Its been a while but the initial problem was a melted gear. That is the metal appears to get so hot it melts the lobe to more of a circle. So are you saying possibly the carbs setup/poor condition could cause?
wish i would have bought the smaller real 2 stroke
 

Rivets

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Yes, a lean mixture will cause over heating. Also, what did you set the valve clearance at? The still tech manual says 0.1 mm or 0.004 of an inch. If the intake clearance in set more than that, it could also result in overheating.
 

daveinluray

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yes. bought a gauge and cut it to fit at .004. recon I am going to learn how to rebuild one of these carbs. thanks for your help.
 
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