MZ/MuZ Riders

In the process of resurrecting my ETZ 251. The top nut on both the front forks are seized solid, any clever ideas how to release them?

I've squirted liberally with releasing fluid, and have even tried a socket with 2 foot lever to try and break the joint, but it's stuck solid and if I try any harder am in danger of rounding the nut

One problem seems to be that, given the design of the top nut, squirting releasing fluid in the top doesn't actually get to the stuck threads, as it's more of a cap onto the stanchion with the thread inside the stanchion tube. I've tried squiring up from beneath the top mounting but I don't think it's getting there either. I also wondered if there was any way to push the whole fork up a bit through the top mounting just to get to the top nut thread joint, but given that I'm pushing up from the bottom against the suspension that didn't work.

Any bright ideas much appreciated, running around with 20 year old fork fluid of unknown level doesn't seem the best idea to just leave it.

I have gotten good luck heating things to just about a red heat.
Use the best socket or wrench that can be obtained.
A six point is the rule not 12 point.
Over here we use Snap-On to save the day.
Point is use a very good tool.
M-

I would also suggest you use a loooong breaker bar - had a similar problem on another bike and made light work getting it off.

Good luck,
nik

you have taken it out of the yoke ,,hot air gun and melt wax in the seam should do it..

Cheers for the suggestion guys, I'll go buy a 6 sided socket and give it another go with some heat. Will eat 3 shredded for breakfast to give me strength to break the rust

It seems a bit of a shame with a brand new socket, but if there is a bit of a chamfer inside it, it may be worth grinding or filing the end flat, as the nut isn't very tall.

Also, I'm sure you have by now, but take the petrol tank off first!

Yup I would go for grinding the socket flat so it contacts all the nut, then I ten to use a breaker bar with an old TS fork leg for extra leverage. Never went to the expense of a 6 sider and even if you do you need to remove the chamfer, otherwise you are only gripping on the top 1mm of the nut

heat… plenty of it, get yourself a gas blowtorch (cheap sort that use gas canisters will do).. and a good six sided socket as stated. and a 3ft breaker bar. if you don't and it all goes rather pear shaped.. it will be more expensive to remedy than using the right tools will be.

Try boiling water. Worked on mine as it seems to melt whatever was used on the threads in the DDR. Struggled like hell with no luck before I tried it. Then it was an easy job.

Agreed.

Boiling water dribbled slowly over the nuts (sounds painful) and allow it to heat soak for a minute or so, then a six sided socket on a 2 foot breaker works for me every time.

Nice one guys, all sorted now. The trick as suggested was using a tight-fitting 6 point socket in combination with heat. The first six point socket I bought was just slightly loose and wouldn't do the job, but I found another one called a Sealey Walldrive socket which was nice and tight and gripped the sides of the nut really well. In combination with some heat from a plumbing blowtorch and a breaker bar all was good. One of the reasons it was stuck turned out to be that the threads were full of 20+ year old glue-like sealant, which the heat melted enough to unstick things.

Now I've only got the stuck gearbox oil drain plug to get off - can't get a socket on it at all as it's fouled by the footrest bar, and heat and stilsons don't want to budge that one. I wonder whether just to leave it and try draining the oil out of the detent hole and side drain plug, rather than rounding it completely.

again.. remove footrest bar.. easy enough… heat, a tight fitting 6 sided socket and take your time.. very easy to strip the thread from a alloy casting.. problem will be a steel sump plug into a alloy casing will have caused reactive corrosion welding.. also plus gas is worth a try.. you really need to get the sump bolt out along with the detent hole to get the oil fully drained.

It`ll obviously help your cause if the crankcases are good and hot from the engine having been run for some time.
Good luck with it.

Sometimes I don't see the obvious.... of course removing the footrest bar as you suggest Cerberus so I can get a socket on rather than messing around with a spanner was the solution. One purchased 17mm 6-point socket later and it came off easy as pie. I will have to find the money for a full set of 6-sided sockets, they seem loads better than the 12-point ones I've had for years.

ETZ251 now back on the road with a fresh MOT and only 55 quid insurance

Thanks for the assistance all.

I loved my set of 6 sided surface drive sockets.... unfortunately some little scrote nicked them from my garage. When I got some cash I will get a new set. Good tools make life so much easier.