MZ Gearshift return spring.

[nice2day]

After waiting a month for an order to turn up I find the gear-shift spring (Item: 29-47.006-DDR) is much bigger in diameter. The original (which has done only 9000miles) has a coil diameter of 23mm whereas the new one is 27mm. This results in the spring moving around on the gearshift shaft and also causes the 2x legs to be further away from the locating peg and consequently they nearly miss it.

mz shift spring.JPG (10.08 KiB) Viewed 2886 times

Does anyone now if the diameter was changed in later years or have I been sent the wrong one?

Many thanks...I am desperate to get my engine together so might use the old one. My fear is that if the old one breaks I will need to strip the entire engine down again..... :
Les

[Guesi]

the one you got is for TS 150.

It seems you got a real competitive supplier

[nice2day]

Many Thanks Guesi for that information. The seller has not even bothered to get back to me following my message to tell them the spring is too big. I kick myself for forgetting about your shop as I would have bought everything from you. I feel I should apologise for overlooking it

In your shop I see you have an original quality one and an improved one. Are the dimensions the same as regards the coil diameter and wire gauge (thickness)?
I certainly want to fit a spring that will hopefully last a long time. Once again many thanks for your help.


Les

[Guesi]

Hello

The sizes are the same on the origial ones and theimporoved ones.
So both fit on your engine

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[Blurredman]

Agree with Puffs. Mine has 46k on it. I had the change to change certain springs when I had the engine apart but I actually decided not to change them on purpose.. I want to see if they will ever break.

I must say, that although my 251 has 46k, I got it at the 29k mark, so who knows what had been done in that time- some bad things I know that much!

[nice2day]

Thanks Puffs and Blurredman for that info. I was under the impression that this was an Achilles Heel with the 250 engine and they had a reputation of breaking with little usage. My Saxon 301 spring snapped with very little mileage from new and I am quite delicate with how I change gears. I'm now in a dilemma ...if only I had remembered Guesi's shop I would have had the engine back together several weeks ago. I suppose now I will use the original spring and keep my fingers crossed. I'm appalled that the seller STILL has not got back to me after attempting to contact them twice...I have spent hundreds of pounds with them over the last year....

Les

[nice2day]

I thought you would like to see the difference. It is hard to believe that such a large well known MZ spares dealer could get these mixed up and then not bother to reply to my 2x emails
The correct original is on the left. As you can see, the big spring moves around on the selector shaft and it has shorter legs which don't reach the locating peg if the position moves away due to the large clearance of the hole.

Les

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[Guesi]

The problem with the original springs is that they have a notch due to the production method. On the picture the area where this notch is is marked with a white circle.
You can feel this notch when you go over this area with your finger nail.

This is the weakest point of the spring (a breaking point).
And if it breaks you have to dismantle the whole engine for this little and cheap spring...

MZ gearshift spring.JPG (41.76 KiB) Viewed 2827 times

[nice2day]

Thanks Puffs and Guesi ...Well I looked over the spring which looked OK but obviously I don't know how much it has "work hardened" or if there are microscopic cracks at the notch but I have had enough of the engine sitting around in pieces so I refitted the old spring and put the 2x crankcases together which went together easily without any problems. With my luck the spring will snap in a few days of completing the whole bike.. But if it does, the bike will have to stay like that for a year or more as I have other bikes to restore and other non-motorcycle projects I need to carry on with...like loudspeaker building, house rebuilding and gardening and learning bass guitar etc. There just is not enough time everyday to wait for a new spring but I have to say I am disappointed I did not buy my parts at Guesi's shop: http://www.guesi-motorradteile.de/.

By the way I think I will install the engine without the barrel and head because it will be so much lighter and it looks like I can fit them afterwards....Any views on this please.

Thanks to all you kind MZ fans

Les

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[nice2day]

Just thought I'd show the complete engine before fitting it which I have now done as a single unit as per Puffs recommendation. It was quite easy but as usual, if I were to do it again tomorrow it would be ten times easier...Photos of the engine in frame to follow soon.
And YES....it IS on the kitchen worktop. but I have to to modernise the kitchen later this year

Les

[DAVID THOMPSON]

other members of the family may take your food away frome you

[Puffs]

Well, that looks spotless!