How many miles on the bike? I will tell you odds are simply replacing the cam chain tensioner with a manual one will take care of your issues. It takes a fair number of miles with a junk OEM tensioner to wear out the chain. I think a number of people here will tell you the manual unit will take care of cam drive issues. My own 250 had 15,000 miles with a bad tensioner, replaced it with a manual tensioner and the cam alignment marks were fine.

As for the cam journals, odds are the scoring was caused by someone trying to short cut the "adjustment" of the cam chain by either sticking something in the tensioner and hitting it to make it advance a click or loosening the bolts until it clicked - both of which will put excess tension on the chain and likely pulled the cams into contact with the journals. Unless the dealer did some heavy sanding they probably didn't take off enough material to affect the oil pressure, otherwise you'd know it by now. If you're running it the set up is doing fine. The bottom end is low pressure for the roller and ball bearing bottom end, which survives using far less oil pressure than the cams. The pressure on the old Z1 at the bottom end was around 10-15 psi! Low pressure high volume.

Your running it upward of 10,000 rpm is proof the head is apparently working fine. Those are pretty much the only bearing surfaces that need the higher pressure feed and must be getting it.

The only fix I am aware of at the moment for bad cam journals would be a new head unless you found a shop that can build up the journals and re-machine them.

 

The bike has 11600km on it now, and i already have the Krieger manual tensioner but not installed it yet. Will do this when the chain is replaced in August.
As for the scoring, i was thinking the same.. Or the previous owner forced it some more clicks or they replaced the tensioner with a new one but did not installed it the right way.. This would explain why the damage/scoring is only on the intake side. I've seen the tensioner and it really looks like new, all teeth are perfect, no signs of wear.
But the tensioner was almost on the end of its adjusting range when they took it out..
The dealer has a good reputation in Portugal and told me he has done this kind of rework/sanding on many motorcross bikes with good results, so i should believe him that its okay. I've driven about 250km after the rework/sanding and it still runs! He was abit sceptic about the MCM when i tried to explain it. But because of the stretched chain i'll do this in August aswell when i have a new chain. Will change to a full synthetic 10w60 oil aswell ,because it can get very hot in the summer.(38+ degrees)
Thanks for explaining the concerns about the oil pressure.
Because the bike in in Portugal and i live in The Netherlands, i try to gather all information and bring my own parts when i go there for vacation. Ordering parts is a slow process there, they only get a shipment once a week, and ordering after wednesday>2weeks!
They also did the recall thing on the bike which only was a couple of rubbers for the gastank and a new bracket for the ECU and some contact grease on ECU/wiring loom connector. The bike still stalled at the traffic lights So i took every electric connection apart on the bike and cleaned it with contact clean and installed a new irridium sparkplug and now its okay! I also read a good post about the charging voltage drop caused by the wiring from the rectifier to the battery. Will do this modification aswell in August!
Thanks

 

I wouldn't bother replacing the chain. With the equivalent of around 7000 miles it isn't worn out. If they claim it is tell them to prove it. There is a specific measurement over I think 20 links. I doubt it has worn to that point. The problem is a tensioner that cannot hold adjustment. Replacing the chain doesn't fix the tensioner. In addition it is possible the second tensioner may fail too, as mine did on my KLX650, same style as the KLX250. The first one lasted 5000 miles, the second was junk by 14,000 miles. The manual one is still in there at 49,000+ miles with 4 minor adjustments running the chains (2 used in the 650) that were put in at 14,000 mile rebuild of the top end.

As I said, I wouldn't bother doing what you plan to do with the cam chain if you can run that bike at 10,000 rpm now. If it is rideable now the head is working fine. Put in the tensioner NOW. If you are going to ride the bike do not wait. All waiting will do is cause wear on the cam drive. It certainly will not hurt anything to put in the manual tensioner now. Plus you got a second gasket in the event you needed it for a rebuild. If the stock tensioner is not working right and gets bad enough you will possibly have the cam chain skip teeth and damage your engine.

Is there any good reason to wait?

If your mechanic is skeptical about the cam chain tensioner consider finding another mechanic. Any mechanic that has an understanding of the cam drive would understand how mechanical tensioners work - that it is a fixed adjustment just like drive chain adjustment.

The Yamaha SR400/500 has used a mechanical tensioner since 1978, virtually the exact same concept as mine. Kawasaki did a complicated double ramp set up that was manual, but the design allowed wear that inhibited holding adjustment. The older RM450s had manual set ups that used a plunger with a locking bolt that wouldn't tighten enough to hold. The simple set up made by myself and others is proven to hold consistently and be simple in design and adjustment. Adjust it in to take up the slack and lock it down tight with the locking nut.

Fact is most racing engines use mechanical tensioners. It takes one possible failure of an automatic tensioner to lose a race or blow an engine if the cam chain slips a few teeh.

 

The bike is in storage now and will not be used until August, then I'll be there for my summer vacation.
Then the cam chain will be replaced as they said it is stretched for sure, and causing the noise.(only 30euros for the chain) Will put the manual tensioner then as well. They know the manual tensioner and also install them on the motorcross bikes!
Good tip to check the second tensioner! This could explain that the first/automatic tensioner is almost at the end of it's adjusting range, trying to take all the slack of the chain if the second tensioner is broken/not working properly!
Ps> The dealer didn't fully understand the Marcelino Cam Mod not the manual tensioner!
Thanks

 

Still, very difficult for me to believe the chain is worn out at 7000 miles. I'd want to see that. I'd definitely want to see the worn out part when it comes out of the bike to KNOW it is worn out.

The chain length standard is 127.0-127.4mm over a 20 pin span. The wear limit is up to 128.9. That is nearly 1-2 millimeter possible wear and as much bearing surface (pin on plate) as that silent chain style has to wear it a full millimeter in 7000 miles is just hard to believe. If the cam chain wore that easily why don't they wear out over twenty-thirty thousand miles with a tensioner that is acutally working properly? They don't.

Think about it... riders here have as much as five times the run time on their chains and they are not worn out. My bike ran with probably at least 7000 miles with a bad tensioner and the chain is not worn out. My biggest concern with cam chain tensioners going bad is if they allow enough slack to skip a tooth, slider damage is second, then cam chain wear and then if run several thousand miles with a bad tensioner, not a couple thousand.

The Kawasaki Vulcan 1500 uses the same designation chain 92RH2010 so I don't think it is particularly under engineered by any chance. I would say a whole lot of Kawasaki's over the years have used that same pitch/width chain for their cam drives.

 

I fully agree with your thoughts about the stretched chain. I also have my doubts. The difficult thing for me is that i don't have the bike at home where i live, it's 2800km away on my vacation adres. I also don't have a lot of tools there, and can't take the risk to wait 2 weeks if some parts have to be ordered during a 3 week holiday. If I'm there i just want ride it!
Thanks for the dimensions of the chain, i will definitely check if it's out of spec.!
Thanks

 

Don't blame you, vacation time is limited time. I just want you well informed.

 

Thanks! I really learn alot on this forum about my bike>from all of you guys!
For example how to remove the KACR which is a good improvement on hot starting! Something that really irritated me when the bike stalled.(which is also cured now Also nice to discuss the problems i have with the bike, to make a plan for the next (work on the bike) vacation! Cheers!

 

Generally, cam chains rarely wear out. I have never heard of one wearing out. Definitely would not happen in 20K, unless the motor was totally abused without oil, for a long time. Auto's with 200K have the same cam chain.

If it was wore out, inspect the cam gears, the teeth would be all pointy and show heavy wear inside where the cam chain runs.

 

Good point! Will check the sprockets to be sure!
(seeing my cam journals, the bike has seen some abuse!)