DRZ goes booooom !!!!!

[crankycraig]

I have just recently had Kibblewhite valves and spring kit installed in a 2000 model DRZ 400 after the original valves were starting to wear. Got a company in Australia to install the valves and the two inlet valves wore out after a total of 160 KM's. Sent the head back and they could not explain why but they repaired the head again with Kibblewhite valves. Got the head installed by a qualified mechanic as per before and this time after riding the bike for 61 KM total the engine went bang. End result the two exhaust valves this time both broke in two putting two holes in the top of the piston, scratching the cylinder wall, totally damaging the head and possibly putting metal shavings down the holes in the piston and into the bottom end. Called the head place that did the work and they are saying that the timing was out and this caused the valves to hit the piston. I know for sure that the timing was ok and they will not pay for the repairs.

1. My understanding is that if the timing was out the bike would have run really bad if at all, even if only 1 tooth out, and seeing as I rode it for 61 KM and the bike ran like a dream until it stopped it would indicate that the timing was ok. Is this correct.

What else could have caused the engine to do this. I have spoken with another head company and they are saying that it had to be the other shop but would like your opinion as well. I have pictures of the damage but don't know how to post them up. Thanks

[eighty6gt]

Those valves are garbage.

https://www.thumpertalk.com/forum/showthread.php?t=351872&highlight=kibblewhite

[BUBONICON]

go to http://imageshack.us/ and host the picture. Cut and paste the hotlink for forums link it provides you ?

Shitty about the moto, hope it works out for the better!

[crankycraig]

[crankycraig]

[crankycraig]

[DRZ-SWEDE]

Check your Cam Chain Tensioner The chain jump 1-2 teeth ?

The tensioner before '03 relies solely on spring tension to extend. At the end of its travel the spring lacks the oomph to put enough tension on the cam chain. I presume that as the chain stretches and the tensioner gets to the limit of it's travel you start to run the risk of it backing out, the chain jumping a tooth on a cam, and piston meeting valve.

Replacing the chain on an older bike seems sensible, but in the manual, there is no data on service limits / stretch, so I don't know if I need to do it or not. ?

[crankycraig]

I have already installed the MCCT as per Thumpertalk recommendations

[DRZ400SK4]

What did the small print in the contract with the company which performed the work say? Was there any mention of a limited warranty on the engine work?

If not, local law will apply.

I'd contact a lawyer. Sometimes just a phone call from a lawyer is enough to make a business stand up and take responsibility.

Beyond that, pay another reputable firm to diagnose the cause of the dropped valves, and put it in writing for you.

Keep us posted as to how you make out. Sorry to hear about the junked motor.

[MutualBill]

The fact that both exhaust valves sheared is suspect of timing...but not conclusive.

Look very closely at the piston. The hosted image is not close enough for me to tell.

If the piston contacted the exhaust valves and caused them to break off...then there should be a perfect half circle impression in the exhaust valve eyebrows on both sides...in perfect alignment with a properly installed valve.

Also...the bottom of the valves will typically have a polished edge that matches that half circle impression...where the rest of the valve is carbon coated.

If you don't have these indicators...then it is likely that one valve head simply dropped off and caused the destruction of the second.

This is possible as one stem is unbent...and the other valve stem is severly bent.

This would be a material flaw...and very likely not the fault of the machinist or the mechanic.

[SheBeast]

That looks ugly!! ?

[Ross Buckingham]

The shop did the work, right? ? And they put in new valves and didn't check the cam timing?! How the hell can they say this was your fault when they did the work unless you installed the head? If you installed the head checked cam timing and valve clearance then you probably got a problem...I'd burn Kibblewhite's email, phone and snail mail with everything I could throw at 'em...I was thinking of putting those valves in, too...Very glad I didn't. Sorry for your wreck and what MutualBill said... ?

[vanram]

The shop did the work, right? And they put in new valves and didn't check the cam timing?! How the hell can they say this was your fault when they did the work unless you installed the head? If you installed the head checked cam timing and valve clearance then you probably got a problem...I'd burn Kibblewhite's email, phone and snail mail with everything I could throw at 'em...I was thinking of putting those valves in, too...Very glad I didn't. Sorry for your wreck and what MutualBill said...

Your not likely to get anywhere with Kibblewhite Precision Machining, as they are an extremely ignorant company to deal with as far as customer service and quality product. They WILL lie and tell you they will get back to you. If you get really upset, maybe a class action lawsuit against Kibblewhite, I'm in. They costed me a scored piston, scored cylinder, rings, gaskets, and they wasted my time and countless others time with their ?. Who knows what happened inside my engine when one of their toilet valves started depositing metal inside my engine. One size fits all mentality and ? the warranty or customer service. I hope I'm not sounding too jaded but I think the word needs to be spread. If you own Kibblewhite valves, return them, if they are in your bike, get rid of them. I am now taking my bike apart to get rid of the Kibblewhite exhaust valves I left in there before thinking the exhausts would be OK. I'll gladly pay for gaskets to get rid of them once and for all. I think I'll send them to Kibblewhite collect. Sorry about the mill, good luck next time, Phone RHC, he uses Ferrea, for all your valve needs. You will not be disappointed. vanram

[Redrodent]

Your valve hit the piston, it didn't fail. I can add that on my 2000, when I added Kibblewhites with spring kit, the valves sat low in the retainers. The valve keepers were worn. If I didn't catch it..... BOOM! Sorry for your misfortune. It only takes one tiny mistake during assembly.

There are some upset people here concerning Kibblewhite's customer service.They have had a run of bad valves they won't own up to.. Yet mine are 2 years old and have not moved one shim size.

Edit: Make that one year. I'm getting senile ?

[crankycraig]

Hope this picture is better quality.

"Your valve hit the piston, it didn't fail. I can add that on my 2000, when I added Kibblewhites with spring kit, the valves sat low in the retainers. The valve keepers were worn. If I didn't catch it..... BOOM! Sorry for your misfortune. It only takes one tiny mistake during assembly."

When you say a tiny mistake during assembly, is that the assembly by the head shop when they did the head work or was it when the mechanic installed the head back onto the bike and checked timing, shims gap etc. Need to know who to go back to.

[crankycraig]

Also need some confirmation about how a bike would run if the timing was out. I have been told it would either run roughly or not at all. What are your thoughts. As previously stated my bike ran fine for 61 KM's. Head shop are saying that the bike would run fine and that I possibly overrevved it. I thought this bike would have a rev limiter and therefore could not be overevved.

[Neil Claydon]

The fault would lie with the person who assembled the engine.

If it ran ok for a number of miles, and then went bang, I would think the most likely cause is the cam timing moved.

Either the tensioner was not adjusted properly of the cam chain guide was not assembled properly.

It is also possible that the valve retainers, were not assembled correctly, and a valve just dropped.

The DRZ does have a rev limiter and should not over-rev.

Neil. ??

[Wayward Son]

they will run 1 tooth on timing.they will lcka power,but still run.

you can overev them even with rev limiters.cutting the spark has no effect on the down shift.

if one valve had broken i would say valve failure.both indicates piston contact.

why is unknown.

[crankycraig]

An update on this problem. I have spoken to a head shop engineer in Australia and he said that he has seen this problem before where the inlet valves wear fast and then the exhaust valves break. He is very confident that it is the valve spring pressure being too high. He explained that the valve springs are closing the valves too hard and the inlets will "mushroom" or wear fast and as the exhaust valves are heat treated they don't wear but break. I have sent an enquiry to Kibblewhite and am waiting on an answer.

The kit that I got installed on my bike included kibblewhite valves and valve springs. Can anyone please tell me what the valve spring pressure should be on the springs that are installed on my bike. With this info I will get mine checked and see if they are different.

Thanks

[harjp1959]

How awful! I hope you get the "blame" sorted out and someone steps up to fix their mistake.