No Cylinder Head Gasket!

[ckevg]

I'm finally forced to rebuild my top end. It lasted two season's so I'm not complaining : ) The issue is that during tear down I found out that there wasn't a cylinder gasket?! The previous owner was a fellow racer that I lost contact with. So I can't get any answers from him. Has anyone run this type of setup? I know it's a "cheater" way to bump compression and therefore HP across the whole powerband. Since late last year, she seems to have been sucking a little bit of coolant from the front passages and is burning it. Whatever liquid gasket he used has slowly but surely lost it's seal. (Hince my "smoke" issue I asked about a while back) The motor is WAY stronger than any other pre 2005 KX250 I've ridden. I thought this was due to the other mods, especially the port job. I'd like to keep the same setup, but at the same time I want a fresh reliable top end. Any suggestions? How much HP might I lose reverting back to using the OEM gasket?

Oh yeah, it's a 2003 KX250.....so I need all the HP I can get : )

[CROGG]

Originally Posted by ckevg

I'm finally forced to rebuild my top end. It lasted two season's so I'm not complaining : ) The issue is that during tear down I found out that there wasn't a cylinder gasket?! The previous owner was a fellow racer that I lost contact with. So I can't get any answers from him. Has anyone run this type of setup? I know it's a "cheater" way to bump compression and therefore HP across the whole powerband. Since late last year, she seems to have been sucking a little bit of coolant from the front passages and is burning it. Whatever liquid gasket he used has slowly but surely lost it's seal. (Hince my "smoke" issue I asked about a while back) The motor is WAY stronger than any other pre 2005 KX250 I've ridden. I thought this was due to the other mods, especially the port job. I'd like to keep the same setup, but at the same time I want a fresh reliable top end. Any suggestions? How much HP might I lose reverting back to using the OEM gasket?

Oh yeah, it's a 2003 KX250.....so I need all the HP I can get : )

By running no base gasket you bump up the compression slightly but most importantly you effectively deck the cylinder. This in turn retards the port timing for more low to mid power with a slight loss in top end power and also peak power. It will rev a bit quicker and feel like it has more h.p. but probably won't....depending on what the person did to the original port timing ect. By using a base gasket you will lose a little snap off the bottom but you will gain some top end power and over-rev. Depending on what the person did to the cylinder when porting you may or may not like it better! You can go to a after market base gasket like a Cometic and it is about half the thickness of the OEM one and may be the hot ticket. Kawi also makes a thinner head gasket to bump up compression. The Pro Circuit pipe works wonders for that bike as does a power valve govenor mod. Changing to a NALF needle in the second position will give you better throttle response and stop the pinging under a load. Drop the pilot jet to a 48 will also help! The 52 is too rich and usually fouls plugs when play riding, even at sea level. Then there is the suspension.........well that's another thread all together!

[Gunjji]

Hey Crogg, good to see you bro, I was actually beginning to think you & KXmanDan were the same person. Both from Utah and you both know ALOT about bikes, especially jetting.

[ElmerFudd]

You know I never once thought about the base gasket and how it makes more compression when it is made thinner, but it all makes sense now, thanks crogg for bringing me into the light! This forum has taught me so much, best thing I've ever signed up for! But now I have a question, how does this KIPS governer mod work? Is it good power for my buck? And will it deplete my engine life in the least? Thanks!

[CROGG]

Originally Posted by ElmerFudd

You know I never once thought about the base gasket and how it makes more compression when it is made thinner, but it all makes sense now, thanks crogg for bringing me into the light! This forum has taught me so much, best thing I've ever signed up for! But now I have a question, how does this KIPS governer mod work? Is it good power for my buck? And will it deplete my engine life in the least? Thanks!

The stock power valve govenor spring is too weak and allows the p.v. to open too soon....by removing the spring and heating it up and stretching it 3mm it stiffens the spring and not only delays the engagement but also the rate or speed in which it opens. It improves throttle response and low end torque. It has no draw backs and actually makes the bike quicker....the next step would be to toss the pile o piece stock pipe in the dumpster and get a pro circuit. This adds about 3 h.p. to the top end, increases the midrange punch and extends over-rev. Then if it isn't fast enough for you cylinder porting would be next to correct the retarded port timing on the sub exhaust ports and a few other things. When properly set up and tuned the 03 will smoke any of the stock 06's.....of course you can also tune any of the 06's as well!

[KXmanDan]

Nicely put CROGG!!!!

[ElmerFudd]

Yes very well put crogg, but just to make sure I follow the spring you say to stretch 3mm is the valve spring, that wraps around the valve shaft and lever in the top end right?

[ElmerFudd]

Hit quote instead of edit :S

[CROGG]

Originally Posted by ElmerFudd

Yes very well put crogg, but just to make sure I follow the spring you say to stretch 3mm is the valve spring, that wraps around the valve shaft and lever in the top end right?

NO! The p.v. govenor spring is located inside the right hand side cover and attaches to the actuator lever below the cylinder. Becarefull taking it apart, there are a lot of pieces that can and will fall out and it is imperitive that you get them all back in the same order or the power valve will not work!

[KXmanDan]

Originally Posted by CROGG

NO! The p.v. govenor spring is located inside the right hand side cover and attaches to the actuator lever below the cylinder. Becarefull taking it apart, there are a lot of pieces that can and will fall out and it is imperitive that you get them all back in the same order or the power valve will not work!

Hey CROGG I don't think the 03 is equipped with this type of power valve, not sure please confirm.
03 KX 250 Drawing http://www.buykawasaki.com/scripts/I...&ilIV=0&ilBR=0 or is located below in the clutch or fly wheel housing?

[ElmerFudd]

I see I see, I'm kinda rushed right now, but I'm going to look into that, my buddies YZ is beatin me, but his is geared to race, gotta get something done here, cause I can't have that