Renewing crank case seals

[bullgoose]

Hi Folks.
Can anyone tell me if any or both of my MZ motorcycles can have the crankcase seals replaced without spliting the case`s and what major workshop tools i need to buy. The bikes are a 1979 ts 150 and a 1979 ts 250-1 five speed with the horizontal head fins.
Cheers.
Bullgoose.

[arry_b]

Yes and yes.

The only special tool you'l need is a clutch puller for each type of engine (you can get away with a workaround on the 150 motor, but the 250 definately needs a proper MZ puller.)

[neddyo]

With my ES 250/2 you have to split the cases as the seals are on the inside of the crank bearings,
I have just replace my seals and if you do it by the manual there are several tools mentioned
IE clutch puller, bearing and seal drifts(punches) and plugs to heat up the bearings for refitting the crank shaft.
The factory manual has very good dimensioned drawings of the tools and a blow by blow description
of the whole process. The factory manuals are excellent and a must have if you want to do the job properly.
Haines manuals are probably better than nothing, but they can also lead you up the garden path.

[DAVID THOMPSON]

Haynes manuals are probably better than nothing, but they can also lead you up the garden path.

at the end of the path is a large pile of horse crap

get the real MZ book and then you do not SALT YOUR BEER with tear drops...

dave

[MichaelTorre]

.........at the end the garden path.......
LoL
Again LOL
M-

[bullgoose]

thanks folks.
I have the facyory manuals for both bike`s but was uncertain if my bike`s had the oil seals in metal cups outboard of the crankcase`s. Does anyone know if the factory tools are on sale in the UK anywhere. (The mz shop for example).
Cheers

[davegsm82]

The TS 250 5 speed should be the same as the ETZ. In which case, you remove the clutch and the alternator, drill a 2mm pilot hole CAREFULLY through the oil seal (it's metal coated in rubber) then screw in a couple of wood screws 180 degrees apart. Pull with a couple of pairs of pliers/mole grips and they will pop straight out (once you've removed the circlips).

Replace the crappy wire circlips with the same type that hold the bearings, they don't pop out for fun then.

Dave.

[therealche]

There is usually someone on eBay selling clutch pullers. Its worth asking them if they include the cap to fit over the nose of the crank as without this you can damage the the threaded portion.

[neddyo]

I have just split a TS 250 and on the drive side there is one seal inboard of the main bearing and on the generator
side there are two seals, one on the inside of the main bearing and one held in a removable seal holder on the outside of the
main bearing.
The reason for the seal locations is that the crank shaft bearings are lubricated by gearbox oil and not by the premix fuel.
I would be surprised if the later engine reverted to the old system where the crank bearings were lubricated by oil in the fuel

[therealche]

The TS250 ( 4 speed) was the last engine with inboard oil seals. From the TS250/1 ( 5 speed) the seals are outboard, and the bearings are lubricated by fuel/oil mist. This ensures the bearings get clean lubrication. When the bearings are lubricated by gearbox oil, the oil deteriorated from the moment it is put in.

[neddyo]

Thanks Therealche,
I must admit I am quite surprised to here that the seals are now on the
outboard side of the crank bearings, but I guess my knowledge of bike engines
stopped when I left the motorcycle industry in the sixties.
Is there anyway a 5 speed engine can by fitted to an ES250/2, I love the bike but hate the gearing.
The high first gear is a pain in traffiic even though my bike has a 20 tooth gear box sprocket instead of the
normal 21 teeth.

[bullgoose]

I have obtained the tools from ebay and will make the cap for the crank myself. The 250-1 has been started and the main bearings sound rough, so the case`s look like coming apart after all. The 150 starts and sounds great but after sitting for over 20 0dd years it`s good to know that if the seals do prove problematic i can sort them out quite quickly. The 150 has 05290 on the clock and the 250 has 31705.

[bullgoose]

Forgot to ask a couple more questions. Which gearbox oil can i use and was there a grade you had to avoid because it buggered up your clutch (type 5) or something like that.
Also on the ts 150 the clock ilumination lights go off in the ign switch No 6 position (far left as you sit on the bike) i believe this is the night riding position .ie. ign on - headlight on - tail light on

[arry_b]

Plain old EP80 GL4 is standard for both bikes. Five litres will be under £15 at a motor factors. EP90 is too thick, especially in winter.

The backlights should be on when you're in position 6.

I've recommissioned TS150s that were unused for 17 years without needing to change the seals, so just keep an eye on the oil level or petroil leaking from behind the dynamo.

[bullgoose]

Thanks arry.
The lamp problem turned out to be with me looking at the wrong thing.