Smelly old forkin' oil!

[Laava]

Stripped 2 prs of forks today for my 85 GSXR750 rebuild and the first pr had the blackest, stinkiest oil I have ever come across! I am not a novice with this job, I have done it on various bikes prob a dozen times before but I have never seen such putrid oil, in fact I couldn't stand having on my hands longer than I could possibly avoid! All the fork internals are stained black, and I mean black as a bats arse, and it may take some removing on the bits I am re-using. Is this unusual or has it just been rolled, bowled and arseholed? I had to do it outside to mitigate the stench levels!
The 2nd pair although externally rough I had put aside but ended up stripping them too as I wanted to start with a better option.

[James Deuce]

The Katana 400 I rescued was the same. Brake cleaner gets the black off. Fresh fork oil is also good for cleaning up the mess, at least for loosening it.

[Kickaha]

Stripped 2 prs of forks today for my 85 GSXR750 rebuild and the first pr had the blackest, stinkiest oil I have ever come across! I am not a novice with this job, I have done it on various bikes prob a dozen times before but I have never seen such putrid oil,

I've struck that once on a set of dirt bike forks, I was dry retching from the smell when I drained it

[dogsnbikes]

Likewise I had that on a Set of XT forks smelt like a chinamans fat trap don't think the oil had been changed ever

[jonbuoy]

Rancid fish oil?

[nzspokes]

Suspensio fluid is the work of the devil. I used to service shocks all the time. I mainly did Marzzochis. I had special "working on suspension" overalls. My Ex would not let them in the house.

[Pussy]

It's quite normal for old fork oil to smell that bad.
I reckon the shithouse door from a Russian trawler would smell better....

[Maha]

..just dont deep fry ya chips in it Al....

[Laava]

..just dont deep fry ya chips in it Al....

Nah sweet, I have managed to track down a russian fishing boat toilet for that!

[Robert Taylor]

Suspension oil should be changed just about as regularly as engine oil. Its there to provide damping, its there to lubricate and to minimise wear, it also performs other functions including additives that are corrosion inhibitors. A rear shock in some instances may hold as little as 150mls of oil. Thats very little oil being asked to do a lot of work for a very long period!
With mx bikes being ridden on a typical track the suspension undergoes approximately 17,000 compression cycles, EVERY SINGLE LAP .
When you purchase a used bike ask how often the suspension has been serviced, if it hasnt or has only been done spasmodically then theres a bargaining chip for a lower price given irregular servicing and therefore accelerated wear. Especially so for MX bikes. Top dollar shouldnt reasonably be expected at trade in or sale time if the suspension service history is poor.
Suspension fluids should not be mixed. If you are changing to a different brand and type of oil and believe you have drained all of the oil out of your forks then think again. There is still a very significant amount of oil trapped in the forks, especially between the cavity inbetween the inner and outer tubes. Cartridges also retain a significant amount of oil. Full stripdown is required, harsh but true.

[Pussy]

You just like sniffing that old fork oil, RT!....

[Laava]

So these 1985 forks are prob overdue for a service then? When the seals start leaking then, is it safe to continue with a total loss type system, topping up with fresh oil?

[nzspokes]

My 86 Honda forks take ATF. So when I drain a tranny the bike gets some new/used fluid.

[Robert Taylor]

So these 1985 forks are prob overdue for a service then? When the seals start leaking then, is it safe to continue with a total loss type system, topping up with fresh oil?

If you want to lubricate your brakes yes.

[James Deuce]

My 86 Honda forks take ATF. So when I drain a tranny the bike gets some new/used fluid.

So many responses. So little time.