125 SM water pump

[MZ125SMey]

Hello Folks!

Sometime ago I noticed that engine oil was dripping from beneath the engine case, preciously from a hole that is venting into the water pump. To cut a long story short, the seal sealing the oil-water interface ripped off and I've had to buy a second hand pump (They come as a whole unit, no chance to order a seal in its own) from ebay.

Now I've noticed that the gear driving the water pump fits somewhat differently from the one I've already owned. Basically, the latter has a wider shaft diameter and it seems that is fits differently too, no parallel pin for example. Everything else, included the interior pump unit, screw dimensions seem to be identical. The only problem is that the one I've bought had the gear missing and as such I cannot re-fit my old gear onto the new pump.

I've contacted the seller and in very broken form of English he confirmed that in principle there are two pump variants for the MZ 125 but they should be equivalent. Anyone can shed more light on this ? I'd like to buy a new pump this time, with the right drive gear, but I am not so sure which variant to buy since in the MZ part pictogram, the gear displayed is somewhat different from mine http://www.grahamsmotorcycles.com/web/125_Water_pump.htm Is it for real that there are different pumps and would it make any difference on switching from one type to another ?

Thank you all!!

[DAVID THOMPSON]

you have not said what country you are located
and you should ask grahams or muz.de the question about the pump and give engine serial number

site has had almost no posts on 125 water pumps
i have 23,000 miles on an rt125 with no pump problems

Dave

[MZ125SMey]

Oh apologies!

The bike is located in Malta with over 50,000 Km on the clock. The bike was garaged for the past 2 years and the cooling system was all sludgy inside. I did purge the lines until fluid came out clear but eventually after some time I started spotting oil droplets. Could have been a consequence of the purge, don't know.

I was of the idea that the muz.de website was inactive or something. I'll look into that.

Thank you Dave!

[malteser]

Hi,

Ironically I had the exact same problem. I am also located in Malta. I bought an MZ as a project and it had a faulty water pump. The pump was really badly wedged in and I had to drill it out. I'm not sure if the engine casing was damaged prior or if I did it to be honest but when I removed the water pump there was some bad damage marks. Anyway I bought another water pump and the one that arrived also came with a fixed pin and was different. Anyway I got the bike running well but then I had that drip also. I opened up the case and the replacement pump had the impeller completely destroyed so unfortunately I gave up spending money on this lovely bike and I have just stripped it down and I am selling it for parts now. It's a real shame though.

Anyhow I'm not 100% sure if I kept it however I think I still have the replacement water pump and it has the cog and seals intact I believe. You can have it if I have it if it helps at all. I am in Zejtun.

[malteser]

Yep. I found it this morning. Feel free to contact me if it's of any use to you.