Squish & Compression & Head gasket thickness

[quincyman]

Are you using a later model kicker? I managed to bust one on the 92 once. then replaced it with the later model one with thicker base. No worries at all. You must be doing something wrong to bust one of them..

I may be doing something wrong but don't know what it is. When your coming down with all your force from tdc and the kicker has some wear in it they just break. I have met with guys on the trail riding KX500's and when we started comparing notes quite often they ask me if I have the same problem with the kickers breaking. I tell them I used to until I lowered the compression. I would be thrilled to know how to get the kicker to last longer. Once they start getting sloppy it's only a matter of time till the kicker breaks. And they always break in the same place (right above the knuckle). I heard that if you buy a new kicker they automaticly give you one of the beefier ones. So I should have the latest and greatest kicker available.

Anyways I have decided to go back to just one of the thicker gaskets. Even though at trail speeds I have never even come close to frying a piston. The only time I fried a piston was my own stupid fault. I forgot to tighten the carb down to the air box and intake manifold. The bike ran better than it ever had until the piston ceased. Live and learn. Always double check everything you work on.

[Timbowe]

The new kickers are noticeably beefier around the knuckle. If you spot a late model kx5 check to see the diference. Do yours break when shes hot or at first strart? I rarely have to throw full weight behind mine to start it. Mostly technique. Or luck maybe.

[quincyman]

The new kickers are noticeably beefier around the knuckle. If you spot a late model kx5 check to see the diference. Do yours break when shes hot or at first strart? I rarely have to throw full weight behind mine to start it. Mostly technique. Or luck maybe.

They usually break when stone cold and with the thin metal head gasket. Since I have gone to the thick head gasket I have not broken one. I don't believe I ever broke one with just one of the thick head gaskets which I did try for a while until I read that book that so many recommend, then I went to 2 head gaskets.

[darrinu]

I used to break kickstarters also got tired of the <$70 a pop so I built a steel arm and put it on one of the stock knuckles I had, end of problem! This was on a 93 overbored .080 and replated way too much comp. with a stock head gasket. I would only get two or three starts out of a stock kick arm after I had installed a thicker head gasket.

DARRIN

[2001KX5]

I ran the 0.4mm HG and got detonation at trail speed. This was running a 50 pilot, 165 main, middle clip position and two turns on the air screw. I found the bike also did not have as much over rev and it liked to be short shifted.

I'm now running the 1mm HG and I have no detonation, power comes on just as strong but it has a nice over rev. I'm running a gnarly pipe and reed spacer and Eric Gorr ported the cylinder.

Perhaps I could of did more jetting with the 0.4mm HG on, but I do like the 1mm HG better.

I'm 230lbs and in 3rd gear with 14/51 gearing this thing can chuck me with a little throttle blip if I'm off guard and lazy and I'm sure it can do it in 4th too.