KL C Head gasket

[The Stroker]

Hi Guys
 Just pulled the head off the 81 klx to find the head gasket has collapsed and gotten caught between piston and bore and completely stuffed the piston. I have 2 questions. 1 is this a common problem if so how is it to be avoided and 2 I am thinking of doing the 270 cc mod do I use a standard head gasket or is there a different ie bigger one. Also who can supply said head gasket.  Cheers Bretto

[grouty]

I bored mine out an extra 2mm and used a 10.5:1 MTC piston (from a KZ1000 big bore kit 72mm). The std head gasket works just fine.
It has run for many years now at 270 (actually 262cc). No issues what so ever.
Since then I have upgraded to a 1"1/2 exhaust and a needle roller Megacycle cam. Again, 1000 miles later, totally reliable. The only down side if any is the fact the compession is higher and so eats kick start knuckles. Partially solved by fitting a genuine TS185 complete lever assembly. They last a lot longer.
Just make sure that every time you remove the head you replace the head gasket (ring) and the O-rings. I always replace the head bolts too as they are designed to stretch.

[shelpi]

if you stand on the kick lever on the compression stroke gently but firm enough to feel the engine roll over to the end of compression, the next stroke is the firing stroke and is the best one to be kick starting on, 1) there is no comp rebound, 2) the engine starts easier
This is how to start big bore bastards and feels easy
and if you have a decomp lever its the same deal but you let out the compression as you find the G spot

[grouty]

I think I might know about kick starting a four stroke. I race a '73 520 CCM. My legs and ankles are still attached to the rest of me. 

[shelpi]

I think I might know about kick starting a four stroke. I race a '73 520 CCM. My legs and ankles are still attached to the rest of me. 

not having a go just trying to help, sorry if I have hurt your feelings

[grouty]

[/quote]
not having a go just trying to help, sorry if I have hurt your feelings
[/quote]

No feelings hurt 
I think the main issue with mine is that the kick lever swings down and contacts the back of the footrest bracket. It has done it since new. Not sure whether they all do it ? But I reckon this is why the knuckle is short lived.

[Tim754]

They do all do it !  Sold a lot of kickstarts for them earlier on

Cannot recall the gasket gobbling thing though Take that as just bad luck friend and now fit KZ1000 piston of whatever oversize

[cloggy]

 I only replace the O rings if they've flattened. The cam chain one is expensive. I also check the stretch on the head bolts but I only change them if they've stretched a lot. So far all that has worked for me but I'm running standard roller cam and compression. I had a race cam in but it was down everywhere except the top end. If my bike was running the same piston as Grouty's I'd do as he does re the head bolts at least.
 Funny thing about the exhaust. I have two exhausts both Kawasaki. One is bigger diameter. I assumed this would be better, but an engineer friend who designs and builds exhausts to boost power on microlights said that, given the size of the exhaust port and valve, the engine actually needed a narrow diameter pipe to improve torque, and narrower than the smaller one too. The Honda two valvers all seem to run very narrow diameter pipes and they generally make better power than the KLX. Looking at Grouty's non standard exhaust that looks on the narrow side.

[Bikeaholic]

I think the main issue with mine is that the kick lever swings down and contacts the back of the footrest bracket. It has done it since new. Not sure whether they all do it ? But I reckon this is why the knuckle is short lived.
[/quote]

That is a common problem. KX's & KDX's of the same era all do it. Since I wrapped a piece of inner tube around the kick starter in the spot where it connects with the foot peg bracket I have never had a problem. It softens the blow. Had some mates breaking the knuckles too until they used this trick.

[grouty]

I will try the rubber buffer on mine when I get a chance. No idea why I didn't think of that before .... thanks 
I still have a stock of NOS TS185 Suzuki levers complete, probably why I am a little complacent.