kx125 compression? lord knows. - Kawasaki Forum :: KawasakiWorld.com
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post #1 of 3 Old 02-15-2013, 08:24 AM Thread Starter
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kx125 compression? lord knows.

so, 2 weeks ago i was out riding my beautiful kx125, shifted up into 5th and there she blows...antifreeze right out the tailpipe and all that good stuff. now, she still started just a tad but would die..of course, because theres water in the engine. but i replaced the headgasket and now it WONT run. usually, when i kick it..when its running, itll turn over a few times (not starting up of course) but now, it turns over only ONCE with a little too easy of a kick. each time with the engine turning over only ONCE. and when i kick it over a few times it gets hard to kick. and back to easy again. can somebody please help? i miss my bike..badly. im thinkin maybe its the rings?
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post #2 of 3 Old 02-15-2013, 09:12 AM
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My son bought one of those bad ass bikes new in 04 and still has it.The service manual says to rebuild the top end like every 100 hours or something crazy like that.It`s not hard.Put a piston and rings in that bitch............

2000 zx12r 65,500 mile( Now 6000 miles on 2003 brand new engine} street bike 9.6`s in the 1/4 a few times.My 2012 14r stole me away.8.9 swb stock engine Brocks bolt ons so far..Now my H2 piss`s on everything. H2 now Brocked out and I can`t control it. Oh well I tried.
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post #3 of 3 Old 02-16-2013, 08:11 AM
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Rings are usually fairly consistent, they didn't ought to change much between kicks.
Get the head back off, turn the engine over slowly and see if the piston runs up and down properly. If you're gasket went bad enough to get coolant through the engine it may well have hydraulic'd the piston and damaged, big end, little end, con rod.
I recon you could be looking at bearings, con rod. Change piston and rings while they are out. If your piston has flapped about a bit and the rings have scored the barrel, you may need a replate it too.
That all sounds like a nightmare, but the beauty of 2 stokes is that it's really not a big deal.
I've seized 250 2stroke pistons. Apart from the wait to get the head back from nicoseal plating, its was 2 or 3 hundred dollars for bearings, vertex piston and rings. New plug and reeds and you have a virtual new engine!
If you do a rebuild, run in properly with atleast half a dozen heat cycles before you ask too much of it.

When you say you replaced the head gasket, I assume you mean you had the cylinder head off so you just exposed the piston top? Most of my bikes had rubber O rings up there.
If you haven't taken the barrel off, definitely look down on the piston top and turn the thing over slowly.
When you remove the head, you are likely to get coolant into the barrel. Are you sure this hasn't made you think that there was coolant going through the engine?
What were your symtoms? A bang? Did it just stop? Just a burbling lack of power 'til it stopped?
With 2 strokes there really isn't that much in there. Check your reeds, I have had them break and go through and out. Once you have a bit of reed missing the bike wont go.
Also if you don't get the bike hot enough it is easy to foul the plug, this will bring it to a stop. If the plug is dark and sooty, get a cooler plug. ie look at the part number it may say 8 in its number, try a 7.
I never rode my last race bike hard enough, 9's fouled up, 8's were fine. Just maybe you haven't been thrashing it hard enough. lol.

If at first you don't succeed....take a longer run up!!

Last edited by SHEP; 02-16-2013 at 09:15 AM.
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