Tappet spalling

[Wierpig]

My second airhead and it has suffered the same tappet spalling as the first one. 35,000 miles and all 4 are shot.
I personally suspect sporadic use and low zinc modern synthetics. Is it a common complaint? Because Ive replaced 8 of the little bastards in two years..

 

[mikeyboy]

Crikey,
More info needed.
What model bike,?
What’s the camshaft look like.?
Is the oil jet blocked?
It’s been run on synt oil?

 

[Wierpig]

The first bike, a 1995 R100R had 45,000 miles on it and a full history. I bought it 4 years ago and it had been stood for a while. Oil used had been Castrol GP10/40.
I stripped it because I found the pin of doom stuck to the magnetic drain plug and found the spalled tappets as a consequence. The cam had some wear so I replaced it.
I sold the bike i June this year and travelled to Germany to buy a R100GSPD 1995.35000 miles.
There was no history with this bike but it was in great condition, and rode well. I did a service before riding it home.
I think it had also been layed up for a while and may have had synthetic oil in the engine.
The gearbox definately had synthetic in as some of it ended up on the rear tyre in Belgium! ( I contacted you Mikey when I thought it was the final drive seal )
While waiting for my Nova certification, I pulled the sump off to have a look.
The cam is perfect. The bores are perfect. No metal filings in the oil filter or anywhere else.
Is this common or have I just been unlucky?

 

[DrFarkoff]

You have been unlucky

people think that they are doing a great thing by using fully synth in these bikes

Good old fashioned 20W50 is perfect, Zinc rich is even better

People are that anal about oil they forget that these engines have been on the go since the 70s in various iterations R60/5 R75/5

It is the same part number for Cam followers throughout that period 11321262638

Anyway "Personally" For me, if it was built back in the day with Mineral oil? That is what it gets!

I am not even fussy on brand as the "Spec" has advanced so much since the 70s its better than it was spec'd back then

a side effect that I have come across many times after new owners changed to Fully synth in these old engines was that they develop oil leaks

A few times I got a call asking If I could change seals and when asked they told me about the fully synth change I recommended that they just go drop the oil and refill with 20W50 and see what happened Every one was the same they dried up after about 50 miles

 

[Wierpig]

Just found the pin of doom is missing..the empty hole is visible with the lh cylinder off...

 

[Wierpig]

Well, the hole looked empty with a mirror. I put a £20 amazon phone endoscope in to have a closer look, and it looks like an alternative pin / staking method has been utilised. Any thoughts on this from more experienced chaps?

 

[DrFarkoff]

If it is in there ??

Job Done Walk away

 

[mikeyboy]

My two penneth.
All of that metal that’s come from the cam followers has been picked up and passed through the oil pump,,unfiltered.
Hopefully the oil filter has done its job.
I’d be removing the gearbox to inspect the pump and housing.
I’d also pop the Conrods off to look at the big end shells.
Any evidence of problems on the big ends would then move me to take the crank out