Valve clearances
 

Hi guys

I got my valve clearances checked yesterday and got a nasty fright. I estimate my bike has done no more than 9000km (5600 miles), and even the dealer agreed that the problems I was having starting the bike shouldn't be valve clearance related, but when they stripped the bike doen and checked they could not check the intake valve clearances. They had to put some other shims in before they could measure then put the correct shims in. Exhaust were fine and in spec.

Now, I will be the first to admit my bike has not had an easy life, and I cane it when I ride it. For about a year it was both my on-road and offf-road bike, and when I took it offroad it got a proper flogging. On my daily ride to work I am not gentle on the throttle either. So I was not too surprised that the valves were out of spec, but I certainly didn't expect the intakes to be THAT far out of spec.

So just a friendly reminder to forum members that although the KLX engine is pretty much rock solid, it is not indestructable. Certainly mine isn't anyway.

My concern now is what longer term damage I have done by leaving the valve clearances to get to the point where there was no clearance to measure. Presumably I am going to need a top-end rebuild sooner than most because of this. The dealer advised only 1 more re-shim before doing a rebuild, which sounds reasonable to me. Anyone else had to do a top-end rebuild this early? Any advice?

Oh, for thos wanting to know, the symptoms the bike showed leading up to be getting the clearances checked were increasing difficulty to start the bike - especially when cold. On hard deceleration the bike seemed to die as well. No noticeable decrease in power or general problems in the engine running once started, though I did think the idle was a little irratic. That's why I pulled the carb and gave it a good clean to see if that was the problem before taking the bike in for a clearance check.

Nice post and good warning. Was this the bike's very first valve check and adjustment?

Thx, interesting thread.

Can you go into a little more detail on seemed to die! I fitted some 101 Cams & when I rev my bike the hard, there is an almost dead moment (for a milli second it could die) before the engine is back at idle speed. I got away with not having to shim after fitting them (by 1/1000th) but they are a little noisier now & with your "die" comment I will seriously think about having the clearances checked again. But on the other hand my bike is EFi & not running 100% yet, so i'm hoping it's a injection MAPPING problem.

Yeah, it was. Not supposed to need it until 12000km/7500miles according to the service manual.

So, it had to be on hard decelleration - like from 8000rpm to zero throttle typre decelleration. And when I did that the engine did not want to re-fire when I gve some throttle - the engine would just die and I would need to hit the e-start again to bring it back to life.

Hope that's clearer now? I did not notice any new noises or anything - I suspect if it gets to the "noises" stage we are talking about the valve hitting the piston and that would be damned near catcastophic! :eek:

Ride it hard and things need checking / doing before an engine that is used not as hard

BS. For some reason my valves need adjusted about once a year. And usually i find out that they need adjusted because it wont start. No biggie anymore. Usually when it wont start there is no clearance on the intake side. That has happened 3 times i believe. maybe 4. rebuild!?!?! your dealer on crack?

Thanks for the reminder, keep meaning to check mine this season.

I saw other recommendations on here (old thread) to check by first 1000 miles. I had mine checked almost immediately after buying a used '06 with 3000 miles and they were in spec. Now at 7000 miles with 351 kit I had head cleaned, guide seals changed, valves lapped, and they needed to shim some of them.

Interesting. Great to hear soemone with ACTUAL experience with this. So basically I will keep reshimming it till I cannot get the right size shims any longer?

Glad to hear I am not the only one that has experienced totally closed valve clearances and that the symptom is a non-starting bike. Gives me some comfort :)