new top end question

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jbowens2401
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new top end question

Post by jbowens2401 »

I just put a new piston in my friends 2004 kx125. Before putting in the piston I had to put the idle screw in almost all the way so it would idle and it only had 130lb of compression. When I started it the 1st time after doing the top end. The idle was really high. I was wondering if this is normal. It also seemed like the engine warmed up quickly. Maybe due to the lack of coolant in the water jackets on the initial start up. Am I worrying over nothing or should I check something to make sure everything is ok. I didnt ride the bike...just warmed it up and shut it down for the first heat cycle.

Thanks

John
KarlP
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Post by KarlP »

First starts are always a little scary.

Bleed air out of the coolant as best you can and turn the idle down.

Check everything twice- reed block, carb boot, coolant level.....hope all is well.
'08 KTM200xc
'99 CR/KDX Hybrid with that RB stuff done to it
KX100 for the boy
jbowens2401
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Post by jbowens2401 »

Thanks karlp, I double checked everything. I'm going to run it through another heat cycle when I get home. I turned the idle screw out 1/2 turn. This bike has a mikuni carb and the idle screw has a 8mm lock nut so it's hard to change on the fly. I'm hoping the increased compression is causing me to have to lower the idle and not an air leak. When you run your bike through a heat cycle, do u let it warm up until the cylinder is hot or until the rad cap is hot?
KarlP
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Post by KarlP »

Radiator cap.

There are a lot of threads on here on the subject of break in.

Have some confidence in your work, Man!

If everything is O.K. it'll be fine. If it is not it is going to have problems no matter how nicely you treat it.
'08 KTM200xc
'99 CR/KDX Hybrid with that RB stuff done to it
KX100 for the boy
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