MZ ES 250/1 shifting issues

[grimstone]

i will get those isolators. In the mean time i get the b8hs ngk which is equivalent.
Regarding the rattle
Took the head off, piston is perfect, no play, nothing. cylinder walls also perfect. Now i found a loose screw in between the fins.... and I think I know where the rattle comes from (used a medical stethoscope) It seems to come from the carb and I suspect the needle is rattling in there because it is adjusted too high. That can explain the huge amounts of smoke the bike produces and the fouling of the plug. I will see tommorow. Keep you updated.

As for the rubber stop of the starting pedal , the original is long gone and will need replacement

[Blurredman]

Yes it 'could' be the slide.. My brother has a cheapo carburettor replacement and gets a similar sound from his bike sometimes..

[grimstone]

It is something in there definitively. I repositioned that needle lowering it and now on idle the sound is gone but when pulling the accelerator it starts again but not so loud (ps I now remember that when I adjusted the clutch i also looked in the carb, cleaned everything there on the slide part -so it can be that there is no more dirt there and the slide is loose and rattling now or that needle is rattling (it is a pain to readjust since it has a stupid system and when you insert it back it gets out of adjustment very very easy)). I can live with that as soon as it's not something inside the engine, because the carb will get changed anyway to a original BVF, Bing or Mikuni.

Now about the gear change.
With the wheels down it will not get out of 1st and will rattle when try to engage second. with the chain off or the wheel not touching the ground it shifts almost perfect. The person who assembled the engine for sure did not use a hot plate to set the bearings so my theory is that one bearing could be placed crooked and.... gear changing issues. I read this in manual and they say there to be very careful about this. They even have a picture with what might go wrong. During riding gears are changed normally ... So maybe I should ride it and see if the problem persists until I have the time and nerves to completely strip the engine and redo everything?

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[grimstone]

It was small screw between the cooling fins on the head )

I will apply your grease trick and see in the rattle dissapears... good advice , thx. I'll check taht later since now at office.

I tried riding and it shifts as close as normal ... not as my bmw 2001 but for a 60 year old bike.... it's good.

Now I am contemplating to buy a replacemnt carb (see my other post) and I am more and more settled to buy a BING or even Mikuni even if I have to mod a little to fit the mikuni.

What info I found it seems like the BING 84/30/110 is a direct replacement with minimal mods and a lot more stable. I do not know if jetting from BING 84/30/110 will do but i see a lot of jets available for this one.

[grimstone]

Here is a tuff one:

Bought yesterday the b8hs but they do not seem to have tge good reach into the conbustion chamber, neither do my other plug. the b8hs serms short and the other seems long. See pics attached with plugs mounted in my reserver cylinder head (175/1 but they are the same as 250/1).

Any thoughts? Bike starts with the b8hs and idles ok, engine a lityle quiter I think... but still. The electrodo should just protrude with the tip where tge spark is generated inside the chamber...right?

Should I create a new toppic on this?

[grimstone]

Coming back to the plug: yes it should be a short shaft model, and yours is odd. I count 10 windings on it, vs. 8 on the one Guesi showed. I see the ring is off, and there also is the small hex size. Anyway, an NGK B8HS (or B7HS, is what I used most in my ETZ) should be fine.

Please see 1 reply above ... Need a new thread for this?

I'd be surprised if a needle would be that loud, but a rattling slide would make sense. And I read you also did some work there, including cleaning. It might be that there was some oil on that slide before, so that the rattle was inaudible? To test: take the slide out & put a little bit of grease on it. If then it's gone, you've found it, and then it's not something to worry about. If it still rattles it's not that.

The test with the lube worked. I can sleep good at night . Rattling is gone.

Bearings will not be 'crooked', but they may be not fully inserted, thus give axial load. Yet that mainly pertains to the big main bearings, so the ones on the crankshaft, which have little to do with the gearbox. But yes, shifting issues may be caused by the engine assembly, or bent shifting forks/shifting shaft, or another mechanical issue. But if it shifts fine without load, that's a good sign.

If it sounds OK (so if you tamed the rattle), I would indeed try to do a little riding and see how it works in real life. As said, many bikes shift poorly standing still with some clutch drag. And sometimes you need to rock the bike front <--> back to get it shifting.

I think I will have to settle down until I will do full rehab on the engine.
I will ride (as much as I will do since it makes no sense of riding the old 60 year bike every day - because of parts wear and overheating in the city traffic) and only put on neutral when the wheels are ok or stop the engine..... The clutch is adjusten now properly and GL80 oil is in and is no difference. I will try the sae40 from a manufacturere to see if it changes anything.

Next things to do on the bike until I get it MOT are:
- electrical for the front headlight horn (someoane torn the cables on switch side)
- see why the engine is stopping when I switch to full lights
- figure out if my spark plug reach in the combustion chaber is ok
- clean brakes to restore braking power
> MOT

In the mean time fit new carb.
Guys from tkm-racing recommended this:
https://www.tkm-racing.com/artikel-12671.htm
But I have to se how I fit it. Does someoane know if the intake manifold from ES250/2 clamp on intake manifold side will fir the ES250/1 or I will have to cut the clanp side from the ES 250/2 and weld it on the ES250/1 ?

After ful strip down and:
- chrome wheels and new stainless spikes (bouht 2 sets fro e-spokes.eu)
- full paint job and figure out how I am going to paint the stripes ..(sandblasting, zinc coating, painting >does anyoane know the color codes that were originally on the bike?)
- all rubers put to white/beige
- chrome all others parts that need chromming
- get new stainless bolts
- eliminate all engine leaks (the ones that I can)
- polish engine
- 12V conversion
- eliminate the lateral fron and back flashers and put handlebar flashers as original
- full led on every light to minimize consumption
-

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[grimstone]

Yep ,
I open a new spark plug thread as I am going deeper into this. I will also compare with oscilloscope the burn quality and wll post in the other thread.

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[grimstone]

pls see the spark thread. posting there