head damage klx300
 

took my bike to the shop to get the valves checked and a few other things fixed.
When i went to pick it up they told me my head was toast. they "shimmed the ****" out of my valves.
02 klx300r... Cheapest replacement i can find is 530$. Is it really to the point where im just destroying my engine by riding it? i get its a wear item but if i cant fix it for a month or so should i just leave it in the garage?
If the head is bad.. i wonder what the piston and rings look like..

What causes this kind of damage? lack of oil?
sent me these pictures-

Wow. I can't think of anything but lack of oil or poor initial installation (no assembly lube)

Did you buy the bike new?
Looks like it was run without oil or has a bad oil pump.

Could be a clogged oil passage. That cam cap has small passages that bring oil to the cams and chain. The manual recommends blowing air through the passages, to make sure they are open, any time you have the cap off, like during a valve adjustment.
Sorry to see that. Illking just posted some similar damage on his 09 KLX.
Best of luck.
Dan

Well its a shame, no i bought it a few months ago very cheap (get what you pay for) street titled 2002 klx300. I really love this bike so far its the perfect scooter now that i re-geared it 15/47 cruises at 55 easy!, i got a great deal ($1100) and i dont mind putting the money back into it. unfortunately i'm going to have to sell my RM250 to do it but i live 45 minutes from all riding spots anyway.. and i'm kind of looking into getting an atv.

The oil passages are the silver tubes correct?
Can i run alittle extra oil in the bike until i sell the RM to fix it?

Now i also have to ask.. is a head a part that wears like this over time and its common? or is it lack of maintenance?

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That's a failure issue, not a wear issue. Best guess is that oil starvation due to low oil, a blocked oil passage, or a pump failure is the root cause. Honestly, low oil is by far the most likely culprit as the other two issues aren't that common.

Adding more oil to the engine won't help that problem.

May be able to save the head if it's not too bad. Friend did his klx650 spinning the assembled cam with fine polishing compound, on the bench with a drill motor rigged to turn it. When done (good enough anyway) it was just at the clearance spec. Bike still runs good today. It was oil starvation that got him, not uncommon with the 650 when run low on oil. ANY bike that runs oil film lube on the cast journals needs clean oil supply also. Even if the oil is topped off, if the filter is dirty enough to bypass you'll see accelerated wear here.

have you looked on ebay for a replacement?, a 300 cylinder will fit a 250 so a 250 head should fit the 300.
If the oil filter is put in the wrong way around it can course lubing problems,
don't put a new head on and run it with out checking the oil pressure.

"Best guess is that oil starvation due to low oil, a blocked oil passage, or a pump failure is the root cause."

Well the owner had let it sit 2 years, then got it started a month or so before i bought it i guess the passages could have gotten gunked up? once again they are the silver tubes outside of the engine right? is the pump behind the filter and how would i know it has failed?

" a 300 cylinder will fit a 250 so a 250 head should fit the 300."
Thought about that too- is it a sure thing the 250 head will fit?

Really appreciate the answers guys.

I know for sure any later model KLX250 heads...'06 to present...will interchange with any production 300 engines. I think even the heads on earlier KLX250's interchange too, as it was only the cases that were slightly different.

I would still bet that a blocked oil passage is the problem. Other than low oil level, an improperly installed oil filter or junk left in the motor after major engine teardown, could be a possibility, but even that is rare. The oil bypass valve will kick in with an improperly installed filter, but it may not be up to the task for the engine to constantly operate in that condition over time. You can usually just take it to the bank that this damage was caused by low oil level...usually. You can use compressed air to blow out all oil passages in the oil lines and engine components while you have the engine apart. Even though you don't generally have to open up any of the bottom end to replace a head, I'd pull the right/clutch cover off and look at the oil screen located there...see if it's gunked up with more than the normal amount of sealant and other assembly bits from the factory. And while you're in there, access as much of the main oil passage there to pump compressed air through it for peace of mine.