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Discussion Starter · #1 ·
I've put so much blood and sweat into this bike and every time I think it's about to be ready for the road I notice something else horribly wrong.

After taking the bike for a quick spin around the neighborhood everything seemed to be working fine but it seemed to be getting way too hot. Took the exhaust valve cover off and the cam lobes are extremely dry and have wear marks on them, the cam followers have pale blue and red notes (looks like they've been very hot) Did I do something wrong when reassembling the head and cylinders? the lobes and followers were in great shape when I took it apart to do the valve job, wondering if somehow I blocked an oil path with something or if they just got clogged with old oil from sitting for so long. What would the procedure be to diagnose and fix this problem? I hope there hasn't been a lot of damage done to the parts running for the short time that it did without proper oil dispersion.

Thanks in advance for your time!
 

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Sensei
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Less than 5 minutes of run time (dry) can wipe out the cams and followers....Unfortunately, the only way to check and fully ascertain the extent of damage is to disassemble and inspect each component...
 

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Only real way to check is to loosen the right front head nut, or the big tach drive back bolt, while the engine runs. Within 90 seconds of starting you should see oil come out.
Squirt oil all over the cams and tappets, close it up and start the cold engine, then check one of those two spots for oil flow. Then shut it down fast.....

Sounds like it may be too late, though - those cam lobes don't look good, and like Steve said, disaster strikes quickly on a fo-fitty.
 

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Discussion Starter · #4 ·
What's the big tach drive back bolt? Would I loosen the entire right front side cover (all the scews and follower adjuster nut)? And if I find that oils not getting through, which it seems is the case, what would the procedure be to find the block and how do I clear it out, or is it even worth it?
 

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Discussion Starter · #5 ·
OK thanks for the advice, I'll try out your suggestions and let you know what I find
 

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Same thing happened to me on my 360. Top end rebuild is in order.
 

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Discussion Starter · #7 ·
What ended up being the problem on your 360 and how did you clear it up?
 

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funk2eat said:
What ended up being the problem on your 360 and how did you clear it up?

The pick up screen was clogged with a lot of junk.
 

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I had the same thing happen once. The checkballs inside the oil pump had become stuck, so almost all the oil it tried to pump, got sucked back.


Pull the pump, clean it out with your solvent of choice, and reassemble. Make sure you use a new o-ring where the pump output meets the crankcase as well.

I bench tested mine to make sure. (with the head off and the cam chain clear of the lower sprocket) Its hard on the starter clutch....
 

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Honest Don said:
I had the same thing happen once. The checkballs inside the oil pump had become stuck....
My Scrambler had a similar issue only one of the check balls was missing. No idea where it would've gone. I'm guessing it was gone from day 1 and had poor oil circulation it's whole life. I disassembled a ball bearing and found another ball of equal Ø to fix it. Pumped like a champ after that. I also salvaged the cams even though they had been squealing and were scored. I polished the lobes on a lathe and so far they've been ok. I'll have to see if I can find the pics of what my cams looked like.
 

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I have been looking at a 450 that has apparently had similar problems at some time in the past. For those of you who have had similar problems, how involved were the repairs: time, difficulty, $$? I am trying to decide wether I will be getting in over my head. I can get the bike cheap, but there is no point if it will just sit in the garage:) I appreciate any info. Thanks.
@funk2eat. I hope you are able to clear yours up. It sounds like you have worked hard on this bike.
 

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@nigel. Great link. I am hopeful on this bike. I am going to work the owner for some more information, and give the bike a more involved inspection. If the price is right, I could use another project :roll:
It will need work to begin with, since it has been in storage for a couple of years.
 

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I just skimmed through Nigel's and Funky's cam wear stories and although there was alot of conversation back and forth, I am not certain as to exactly what caused their problems. Was something clogged? Was the oil pump worn out? Was something incorrectly assembled? Or are we saying that the pumps these guys had on their bikes were inadequate from the time they left the factory?

Can we please describe the clear cause of the problems?

Thanks!

Mike V.
 

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The honest answer is nor do I.

The symptoms only came to light when the tappet started getting noisy, after 1000miles from rebuild.

I was scrupulously clean on the rebuild. Though I was not on the forum at that time, so I can't show details of the rebuild.

What I found on the strip down and rebuild, was that there was oil getting to the RT side of the gallery but not the left side.

I checked the bore of the pipe that delivers the oil to the left cam lobe, and although there was a trace of residue
there was no blockage.

I must also point out that I had a product called Active8 (http://www.simplan.co.uk/) in the oil. I believe that this also prevented a significantly greater degree of damage being done. The oil was a 10-40 multigrade from Tesco.

I then drilled out the pipe with small increments as described in the thread.

On replacing the pump and turning over the engine on the starter that there was not much oil flow.
I started the engine with the cover off, still no great flow to the cam lobe.

It was then I remembered a thread about oil pumps by Jensen, and checked it out.

I installed the alumimium bodied pump which that was recomended, which due to the 19mm bore delivers 25% more oil per strokeThe stroke remains the same. You need to keep the con rod that comes with the 450K0 as there is a sligtly greater diameter on the later clutch baskets which would cause wear after a little while. Steve also commented on this.

I then saw good oil flow to the cam lobe.

I will add pics of the pump I removed, but there was nothing wrong with it as a pump per se, except that it did not appear to deliver enough oil.

I also remember that I had to replace the cam for the rebulld due to lobe damage.

Steve and Bill both say that there was a weakness with the K0 at the left hand exhaust cam not getting enough oil.
Both those guys know their bikes inside out, and they were spot on with the diagnosis.
 

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Thanks for the recap Nigel. It still seems mysterious to me. I ASSume that this machine had considerable mileage on it (i.e. more than a couple thousand miles) before you did the initial rebuild and in that time no abnormal valve gear (cam, etc.) wear was observed (correct?). Then, with that same oil pump that did the job fine previously, a thousand miles later the cam was ruined. Regardless, I hope whatever the cause was, you have slain the dragon.

Mike V.
 

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Yep app 39000 however she was laid up for best part of 30 years and in bits for 12 of those.
Though clearly damage had been done to the original cams, as that were badly worn when I took them out.
I will take pics of them too.

But your right it really doesn't make a lot of sence to me either.
Im just glad of the advice I got here from Steve and Bill.
 

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Steve and Bill both say that there was a weakness with the K0 at the left hand exhaust cam not getting enough oil.

Well, all 450's are the same in that context - the 4-speeds are worse because of the smaller oil pump.

There's very little oil pressure to speak of, the oil goes all the way up to the exhaust cam bearing, via the engine stud. Then it wends it way through the cam bearing, into the hollow center of the cam, through the "restrictor" tube, and finally over to the left side of the cam, where it drips through a tiny hole in the base of the cam lobe, onto the tappet........

Whew !!
Same deal for the intake side, but it's a little closer to the source than the exhaust is.

Some guys completely remove the intake cam restrictor tube - it comes out pretty easily.
Then they cut off the end of the restrictor tube in the exhaust cam - it can't be removed because it's a part of the tach drive thingie.

I don't recommend either of those things - but I've done both to my current 450, and it hasn't seized up yet.
 
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