i was going to ask that, but he was able to measure the exhaust valve clearance, so i assumed he was....or...other guess was that he didn't have a valve tappet feeler gauge that didn't go that that thin...but, to ol'klx-er's point...that should be something you need to be sure of...

 

I´ve dropped one inside the case. Easily retrieved it with a magnet. IMO, people un-necessarily make it a really BIG deal if you drop something in the engine. Or maybe I just don´t have enough experience to agree with it.

 

urgh...i dropped things that took me forever to retrieve or find...sometimes, i drop things that i can easily get...better to know that this is something to look out for...and, as a precaution...i cover all holes or open areas with clean rags...a near empty gas tank is much easier to work with too..

 

Yeah i tried it several time. rerotated the motor several times. Exhaust always measures the same. Intake way to tight to measure. The exhaust i can spin the buckets at top dead center. intake will not.

 

This isn't uncommon for a bike with 3-4 thousand miles that never had a valve clearance service, and hard starting is often the first clue.

 

Got the exhaust valves back to spec. One is at .009 and the other at .008.

Ran out of time on the intake. but currently at .0085 for both. So just a hair too loose.

Will get it finished tonight.

 

Sorry to jack this thread but I have the same issue on my 04 KLX300, both exhaust valve clearances are at spec per my feeler gauge but both intakes are too tight for any size feeler gauge I have. Wouldn’t the valve clearance increase over time due to wear instead of decrease? I bought this bike without any knowledge of its history so I’m just assuming valve adjustments have never been done or are overdue. Can anyone recommend which size shim kit I should get?

Thanks, Chris

 

I was lucky and a friends lent me his shim set. Has about 30 different thicknesses to work with.

For the tight intake valves, I measured the shim that I pulled out. They were 3.5mm thick shims, swapped them out with some 2.70mm shims. Then checked clearance to get a base number to work with. Now I need to bring the thickness back up until they are within spec.

 

On bucket/shim and some other valve train designs the valves moving up into the head due to normal wear is where the decreasing clearance is faster than the wear of the other valve train parts. On many rocker arm, pushrod, and other systems, the valvetrain components can wear faster thereby increasing clearance faster than the valves wearing into the valve seats. There are all kinds of variables here, but in the case of our KLX and many other engines, the valves wearing into the head decrease clearance, and the adjustment is to increase clearance with smaller shims. When the valve clearance becomes too small, the stroke of the engine doesn't produce enough vaccum to draw enough fuel and the compression stroke can be diminished enough to lower combustion threshold. At least in my pea brain that's the overall gist of it.

 

OK, I just had mine done...wish I did them with someone that knew what they were doing...but I thought if something were really wrong, better for the shop to see it first...shop said the intake was on the tight side but well within spec...the exhaust was at the max...tried to get more details but the guy seems to be a drunk and couldn't remember...arg.
So how long do I wait for the next check? When it's hard to start?
And what happens once the minimum clearance is reached? Do you then replace the whole top end? Just curious, not really worried.
My only problems with this bike have been clogged jets...and repeatedly...time for an in-line fuel filter(already did the t-vent mod, which helped the off-road water uptake issues I had).