Getting the old lady back on the road at the moment, she is starting fine, running sweet, but after picking up some new gear oil I drained the old oil out this weekend. It looked a little like custard to be honest, cloudly light brown. At first I thought 'sh@# waters been sitting in it' but the M20 has been under cover out of the rain, in a bag most of the winter and not ridden for 7 months, so I guess its just old oil.

Is it wise to use an gearbox flush or even pour a bit of petrol in?

Without taking the gear box out, are there any suggestions to wash this stuff out? or is it just a case of putting new in and changing it after a few runs? any pointers be great thanks. Hopefully by the winter the M20 is going to get it's own luxury appartment in the garden when I put my workshop in prep for Normandy and after I've put a few miles on.

(Also after a new drain plug with fiber washer and some fuel corks right now if anyone can help)

Thanks..

email (option): kit247@hotmail.com

Hi, I definately wouldn't use petrol just fill with the recommended lube
run it for a few miles and change again. I would suspect (as you have ruled out water) that someone has used grease in the gearbox in the past, maybe to cut down on leaks, and its just that. Can't think what else it could be.

Yes, change the oil a few times. but bear in mind that its often condensation issues (inside the box) & the positive stop mechanism will likely be rusty & other areas also that may induce rapid wear.
Its common for old bikes to have lots of money & time spent on them but no attention to the gearbox internals so its worth considering stripping if if its not been done recently & doing a proper refurb/cleanout job on the box if you can.

I agree with Fred..Limited and irregular use, even if the gearbox has been rebuilt, doesn't really get the gearbox very warm and can result in condensation (and rust) problems..Emulsified oil is a sure sign it is happening. The smaller of the two gearchange return springs is particularly vulnerable if the ratchet assembly in the outer cover becomes rusted...Ian...

email (option): ian@wright52.plus.com

Of course!! condensation, why didn't I think of that? Obviously because it never happens with the Norton Patent Oil Replacement Eco System PORES (it leaks out I replace it!)

Kit, put paraffin in there and run the engine for a minute or so, just long enough for it to splash around and degrease it, then fill it up with the correct oil

email (option): davmax@ntlworld.com

If you do that you're not going to get all the paraffin out and I would think as a result you'd dilute your gearbox oil.
Accepting that I'd be inclined to replace the first lot of oil pretty quickly as well...
Once the initial problem is solved, to avoid a repetition you may have to think about changing the oil more often or riding the bike more frequently and for longer runs...Ian

email (option): ian@wright52.plus.com

Thanks Gents, got to be condensation. Gearbox last rebuilt 4 years ago, time to build that shed then hey...

email (option): Kit247@hotmail.com

In the meantime kit, ride it !!!

I'll meet up with you no probs - might get our Nigel fired up too

:-)

Job

email (option): Jonnyob1@googlemail.com

sounds like a plan to me John ,we need to get round a few of those old airfields Kit keeps talking about

I need fuel corks right now, go-go juice is leaking like the Mohne Dam on May 17 1943...

Kit, have you used my synthetic corks? They are more resistant than 'cork'-corks
Just need your address, they are free..

email (option): viaconsu [at] planet'dot'nl