More Problems

[Duccout]

I have discovered a possible major problem with the Mototrans 250...... Fitting the clutch cover this morning I noticed that when the cover is half-way on and the crank end is in the bearing and the dowels are engaged, the gap between the cases and the front of the cover is double that as it is at the back. Everything lines up smoothly and does not have to be forced, but the cover is at an angle to the gasket face.

I can see two possible reasons for this: either the kick start shaft is misaligned, or the kick start bush housing in the cover is bored at an angle to the gasket surface. I am not sure that I have the means to discover what is wrong - I could turn up two mandrels which fit inside the kick start bush and bearing and take measurements close to the housings and then further out to see if there is any discrepancy in the cover, but I don't know about checking the angle of the kick start shaft - maybe a square across the gasket face? I suppose the obvious first step is to try the clutch cover from the 350 on the 250, which would eliminate the cover as the source of the problem.

Has anyone else come across this? Any ideas?


Cheers,

Colin

[Jordan]

To me, it seems your thinking is good.
Good luck.

[Duccout]

Problem solved (sort of). The 350 cover fits properly, so it is the clutch cover that is at fault, so I think that I need another clutch cover. I doubt if the error could be reliably fixed - what do others think?

I could get my local engineers to mill a new kick start bore at right angles to the gasket face, but how to be sure that it is accurately distanced from the crankshaft? I think that the inside of the bore is probably in the right place, so my guy could use the bottom of the bore as the starting point and mill out until the housing is true, then make a new bush, but what if there is an error? It would be an expensive experiment.

I will be hoping to find an Italian clutch cover, as I don't trust Mototrans machining - are all their covers machined wrong, or did the employee not locate my cover in the jig correctly?


Cheers,

Colin

[George]

Hi Colin, could you not provide the 350 cover as a template for machinist to measure before working on faulty cover.Not difficult for man with right equipment. Good luck

[Duccout]

Hi George, I hope that you are doing ok.

Good thinking! I would still be wary, as there are potential pitfalls and I would think that it would be expensive to do - possibly more expensive than finding another cover, so I will see if I can find another cover first.

Cheers,

Colin

[Jordan]

You could be right about the expense of machining.
Skilled labour seems soberingly expensive now.

[Duccout]

Hi Jordan,

Yes, there are hardly any small engineering shops left, and skilled people are hard to find commercially, although there are thousands of very skilled amateurs out there. I am a member of the Model Engineer forum, and whenever I have a workshop problem I ask the guys and loads of people have the answer, they have been really helpful to me. I think that the problem in Britain is the overheads in running a small (or large) engineering business - business rates and the cost of energy, which is driving all of Europe's manufacturing overseas; I believe that we are paying four times the cost of electricity than the USA for instance, and that makes manufacturing here untenable. It was reported in the news yesterday that Britain is no longer in the ten biggest industrial nations.

The small engineering shop that does odd jobs for me is a one-man band, and the guy will attempt anything, and he does not charge a lot, but the biggest expense is the set-up time which can run into hours on a particularly awkward, accurate job. If I could tell him exactly what the measurements are to modify my clutch cover then the job would not take long, but he would still have to turn up a new bush.

Thinking about my cover, it is about 5mm out at the front, so the error at the kick start bush is probably hardly anything, but by the time it gets to the front of the engine it is magnified.

Cheers,

Colin

[Jordan]

I wonder what happened to the factory drawings for making widecases?
In theory there could be a stash in Italy and another in Spain.
It's conceivable they were destroyed.

I have an interest in British brand Panther, who closed their doors in 1966.
All drawings went into skips for disposal, but happily quite a few were rescued by a worker who thought they could be useful.
The Panther OC has had new cylinder heads made as a result, and much more besides.

[Duccout]

I know that new engine covers are available for the bevel vee twins, and even Newton Equipment in the UK managed to get some cast and machined correctly, but I don't know if Singles covers are available. I'll have a look at the Old Racing Spare Parts web site and see if they have made any.

Update: no new covers available.

Colin

[ecurbruce]

Hi Colin,
Is your clutch cover like a narrow case or a wide case ?

Bruce