gear oil

[big mac]

just collected a 301 and as I don't have a manual yet just wondered what gear box oil to use and how much.
also the forks feel very boggy so wondered if this is common was thinking of putting spacers to compress the springs
one more thing how much oil in the forks .
this is my first mz so getting to know the bike feels a bit different to my normal ride bmw gs 1100
must say nice to ride a bike that weights less than a tonne
cheers dean

[therealche]

Gearbox takes 1l of oil when totally drained. Lots of different ideas on the best oil, but a lot of people go for Silkolene Light gear oil-When draining the gearbox Do not remove the wrong plug! The one you need to remove is the one nearest the exhaust, not the one nearest the gear lever. You also want to remove the lower clutch cover fastening screw.

Forks take 250ml of oil each, 10W fork oil ( or whatever you have available!) . Draining the oil is a bit of a bind as MZ didn't bother with a drain screw. So you need to take the legs out and turn them upside down. The top nut may be very very tight. A close fitting socket, breaker bar and possibly an old fork stanchion to give extra leverage may be required. If you are luckily someone has already done this once before and broken the sealing material MZ used.

Easiest way to stiffen up the forks is to get a pile of 2p's. Start with 4p a leg and work up, depending on weight!

[big mac]

Many thanks for that
can't wait to get it on the road
cheers dean

[arry_b]

4p a leg? Pfft, lightweight!
I use 12p a side, but I do like a firm front end, and I'm not light.

Gear oil is 900 ml. Usual way is to put a full litre in, then take out the level screw and allow the excess to drain overnight. Silkonene LGO is liked by some, I like straight EP80. Don't use EP90, it ruins the quality of the change.

Therealche has the right idea for getting the top nuts off. One thing that helps massively if they've not been off before is to slowly dribble a kettle of boiling water over each nut, wait a couple of minutes, then set to it with your (six sided) socket and breaker bar. The heat breaks the sealant's hold on the nut turning it from a bollock busting task, into one that's merely a back breaking one.

[big mac]

whats the plug next to the gear lever !
got the nuts out the forks now my nuts are in my socks

[arry_b]

Which one? The one on the clutch side casing at gear lever height is the level plug.

Under the engine, leave the plug nearest the gear lever alone. That holds the dedent plunger in place. The bigger of the two plugs (22mm - ish head) is the one for the gearbox drain.

Note - that only gets around 1/3 of the oil out, the rest is in the clutch housing. That drains by removing the lower mid case screw.

[therealche]

Have to admit to being a 20p a leg man, but then I am a fat git!

[Tony the Skin]

Recently used on a ETZ251 Spectro Primary Chaincase oil which a lot of Harley Sportster owners use. Gear change was much smoother. Engagement of 1st gear even when cold was smooth and quiet. The improvement was very marked. Used 900cc..

[arry_b]

I'm not sure I'd use primary chaincase lube in the gearbox. It'll give good clutch operation, but isn't all that good as a gearbox lube.

It would be fine on something with a separate gearbox and primary drive (such as a Harley or old Brit), which can have dedicated oils for each system, but an MZ isn't like that.

[mr_luke]

The cheapest 20/50 I can find in Wilko's, for me. I started using it last winter as the gear oil was becoming contaminated with water so quickly that I ended up changing it as often as I refilled the 2T tank! It's not been a problem since I rebuilt the engine (not sure why, really!), but it seems to do the job fine, so I've stuck with it. It's also what I use for the primary chaincase on my Panther, due to the rate it all comes back out again!

[Tony the Skin]

I'm not sure I'd use primary chaincase lube in the gearbox. It'll give good clutch operation, but isn't all that good as a gearbox lube.

It would be fine on something with a separate gearbox and primary drive (such as a Harley or old Brit), which can have dedicated oils for each system, but an MZ isn't like that.

Gearbox on a Sportster shares its oil with the primary. The product has been developed for that purpose ie. a joint gearbox/primary use.

[arry_b]

That's interesting to know. Is it just the Spectro one that's suitable for both the primary and the 'box?

[Tony the Skin]

That's interesting to know. Is it just the Spectro one that's suitable for both the primary and the 'box?

H-D do one themselves but the Spectro Primary Oil seems better. A mate of mine has used it for 50,000 miles on one of his Sportsters. I have used it for a few years on Sportsters and have used it on the MZ. No problems so far.