First MZ...Help!

[alembic1989]

Hi,I just receved my 250 trophy 2 days ago..not only my first mz..but my first 2 stroke...I have a few questions..
!)...I don't know how to pick a 2 a stroke oil for it...not sure about mixing ratios either.
2) The manual says that I should use 79 octane fuel...but here in the UK it is 95...what do I do?
3) the gearbox oil sae 40?
please excuse my lack of knowledge..any help would be gratefully recieved.
thanks
'Raj (UK)

[Old Dog]

Any motor factor will sell motorcycle 2t oil, get at least a semi-syth.
Ratio 50 parts petrol to 1 part oil so 500mls of oil would 10mls of oil therefore 1L would be 20mls of oil then multiply it up by number of litres.
Gearbox I would use Fuchs silkolene light gear oil.
MZs will run on any unleaded so don't be sweating that.

Welcome aboard and happy riding - they are great little bikes!!

[alembic1989]

Nice one...
Now heres the thin g , I don't understand about synthgetic olis, semi synthetic etc..
I live in the UK too..in berkshire..where would I get that gearbox oil?
thanks again...any info about all this oil mularkey would be welcome.

[Old Dog]

If you want to understand the difference then google it. Generally a semi-synth will be fine for an MZ.

Opie oils online do it or a bike or Agricultural suppliers or the like.

[Skorpion]

Now I don't want to throw a spanner in the works, but shouldn't the 250 Trophy have 2T oil mixed at 33-1
I think this was the recommended ratio at the time.

I know modern oils are far superior to oils back in the day, but I don't know if 50-1 is correct?.

[Old Dog]

Happy to stand corrected. I checked the manual and it is 33:1 NOT 50:1, what ever happened to the old premix pumps on forecourts?

My current Zed runs a pump so I only have to watch the cable and the tank.

[stogadog]

I run my Trophy (and have done for two years) at 40:1 using semi synthetic husqvarna chainsaw two stroke. 125 ml to 5 litres of petrol. It runs great on this. I reckon that an oil designed to keep an 18000 RPM chainsaw spinning will happily keep my 40 yr old MZ going!

[Skorpion]

I run my Trophy (and have done for two years) at 40:1 using semi synthetic husqvarna chainsaw two stroke. 125 ml to 5 litres of petrol. It runs great on this. I reckon that an oil designed to keep an 18000 RPM chainsaw spinning will happily keep my 40 yr old MZ going!

Yes that's the answer we needed to know.

I run my Yamaha RD350R on OREGON semi synthetic chainsaw oil and it runs fine with clean exhausts.

[alembic1989]

I run my Trophy (and have done for two years) at 40:1 using semi synthetic husqvarna chainsaw two stroke. 125 ml to 5 litres of petrol. It runs great on this. I reckon that an oil designed to keep an 18000 RPM chainsaw spinning will happily keep my 40 yr old MZ going!

Isn't 125ml to 5L petrol a 25:1 ratio???
I thought you said 40:1

This is the prblem with owning your first 2 stroke...some people say 33:1. some say 50, and now your turn with 40 Aaaaaargh..what do I do?
Will any semi synthetic be ok?

help.

[Old Dog]

It is a case of what works I suppose, despite some people's apparent pedantry.

With a decent oil chances are that 40:1 or even 50:1 will work and I have heard (though I am not recommending it) 100:1.

The manual recommends 33:1 so you are best using that for peace of mind.

Use a good oil, make sure the carburation is right, and enjoy, For now follow the manual and be happy.

PS Something decent, (ie I wouldn't use some generic stuff out of the pound shop.) I prefer a brand label, although I have some semi and fully Synth French Supermarket stuff I picked up on hols which I will be trying later on. Sometimes you can get vast amounts on ebay cheap. I got 25L of Silkolene which is only now coming to an end.

[stogadog]

So my maths be a little off but I worked out that 40:1 was 125 ml by deciding that 10:1 is 500ml for 5litres ,therefore 20:1 is 250 ml and 40:1 is 125ml.
If I'm wrong then the previous point is highlighted that it's not that critical but as people have said if you are concerned use 33:1.
Not trying to be a pedant, just trying to be helpful!!

[Old Dog]

Never suggested othewise, you are right of course, absolute precision is not the issue.

All the best

[Mike G]

Be aware that by varying the ratio you are also varying the petrol to air ratio. Less oil means more petrol so the mixture will be richer. If the variation is too great then the carburetor will need to be re-jetted. This is why people have been caught in the past adding extra oil for safety and weakening the mixture which causes the engine to overheat.

Mike

[alembic1989]

I must admit I never thought of that.
Thanks.