MKIII Date of Manufacture-Cam Issues (2019)

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Cheesehead Commando

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Hi All-
I have recently re-purchased my MKIII after 25 years, really excited about getting it back on the road.

The first four matching frame/engine digits are 3324. Anyone able to give me month and year of manufacture date?

Will the first four digits give me an indication of soft cam lobe issues that seem to have plagued late model MKIII bikes?

The bike has only covered 10,515 miles from new. However, it’s sat unused in a dry and semi-heated environment (above freezing) for 24 years. I would rather not have to crack the cases. But I’m also concerned what 24 years of sitting will do to the bottom end, and also the issue regarding the cam. Assuming the side to side movement of the connecting rods are within spec, I’m hoping to avoid it.

Thank you for your comments and insight!

Tom
 
Cheesehead Commando said:
Hi All-
I have recently re-purchased my MKIII after 25 years, really excited about getting it back on the road.

The first four matching frame/engine digits are 3324. Anyone able to give me month and year of manufacture date?

Will the first four digits give me an indication of soft cam lobe issues that seem to have plagued late model MKIII bikes?

The bike has only covered 10,515 miles from new. However, it’s sat unused in a dry and semi-heated environment (above freezing) for 24 years. I would rather not have to crack the cases. But I’m also concerned what 24 years of sitting will do to the bottom end, and also the issue regarding the cam. Assuming the side to side movement of the connecting rods are within spec, I’m hoping to avoid it.

Thank you for your comments and insight!

Tom
Click to expand...
I've got a late production date 75 and a 76. Both cams are fine, very shiny and silver looking. Mind you , the 76 when I purchased it had been a total rebuild by Kieth Newton so he likely replaced the cam after one of those stoopid anti sump valves stuck closed and the motor threw a rod.
 
Cheesehead Commando said:
However, it’s sat unused in a dry and semi-heated environment (above freezing) for 24 years. I would rather not have to crack the cases. But I’m also concerned what 24 years of sitting will do to the bottom end....
Click to expand...

I am not trying to scare you or even suggest looking but..........

I am yet to pull any old low mile bike down that did not need new big end shells for one reason or another, my concern would be over that duration (24 years) the possibility of acidic oil at the bearing shell compromising the running surface.
There is even a danger that the mains sitting in one position can etch the race at the ball contact also and that might reveal itself once usable.

You could change the oil (a couple of times), fire it up and then hope the oil seals stay oil tight over the first month of running. (I would think an added oil pressure gauge would be wise based on the crankshaft seal) if its a straight into service with an external check only.
 
Time Warp said:
I am not trying to scare you or even suggest looking but..........

I am yet to pull any old low mile bike down that did not need new big end shells for one reason or another, my concern would be over that duration (24 years) the possibility of acidic oil at the bearing shell compromising the running surface.
There is even a danger that the mains sitting in one position can etch the race at the ball contact also and that might reveal itself once usable.

You could change the oil (a couple of times), fire it up and then hope the oil seals stay oil tight over the first month of running. (I would think an added oil pressure gauge would be wise based on the crankshaft seal) if its a straight into service with an external check only.
Click to expand...
Oh I don't think that way. Replace all seals and gaskets every tear down but also inspect big end shells. Seen many old shells that are good 2 go. Spend money yeah !
 
I brought mine back from storage after 20 years and just drained out the "new" oil, put in fresh, and started it up. All it needed was cleaning the pilot jets and de-crudding the kill switch. That was 10k miles ago and no cam or other engine problems, so far. No fuzz on the magnet.
Jaydee
 
As far as I know all the MK3 engines had cams that tested soft. They were manufactured and hardened using a different method.
I have also seen many MK3 cams that tested soft and yet lasted as long as any other cam as long as they were used with good oil.
Unfortunately that was not the oil that was specified in the owners manual when the bike was new.
 
The soft cams in the MKIII's seem to be hit or miss. A lot depends on the maintenance the bike had over the years. Mine has over 60K and the cam still looks great. I recently opened it up to take a look at the original bearings, etc. Although things were in good condition, I replaced the mains, rod bearings, and dynamically balanced it. A bike sitting so long will at least need the seals replaced.
 
Cheesehead Commando said:
Hi All-
I have recently re-purchased my MKIII after 25 years, really excited about getting it back on the road.

The first four matching frame/engine digits are 3324. Anyone able to give me month and year of manufacture date?

Will the first four digits give me an indication of soft cam lobe issues that seem to have plagued late model MKIII bikes?

The bike has only covered 10,515 miles from new. However, it’s sat unused in a dry and semi-heated environment (above freezing) for 24 years. I would rather not have to crack the cases. But I’m also concerned what 24 years of sitting will do to the bottom end, and also the issue regarding the cam. Assuming the side to side movement of the connecting rods are within spec, I’m hoping to avoid it.

Thank you for your comments and insight!

Tom
Click to expand...
Tom, Please check your private messages [aka conversations]
 
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