Forum

[OldBoy67]

Dave

Looking at your pictures has refreshed my memory and I misled you in an earlier answer I gave. There is no threaded boss on the gear change side, just the hole in the frame lug as pictured.

The images also reminded me that there is very little clearance between the reasets gear lever arm and the frame, and on both of mine I had to shim the lever outwards to prevent fouling. No biggee - cheapo stainless shims from ebay fixed it, and I think you have a little more work to do before you reach that stage!

It would have been quicker for me to go out to the garage and actually look, but unfortunately my hip and knee joints are crocked so I'm laid up at present.

[Dave the Bass]

Dave

Looking at your pictures has refreshed my memory and I misled you in an earlier answer I gave. There is no threaded boss on the gear change side, just the hole in the frame lug as pictured.

Aaaah, thanks for that info Mr OldBoy.

Sorry to hear you're going through the wars at the moment with your limbs.

From experience, if you just buy a few things at a time, it doesn't look like you simply emptied 2 month wages into Mr Hitchcocks bank account. You can further add to the denial by not adding it all up at a later date.

Heheheh! I like that thinking Mr stinkwheel.

More news from the shed...buoyed by the semi-successful hole drilling (I'm easily pleased...) over the weekend I thought I'd have a look at starting to clean off the crankcases. They're very dirty but are cleaning up OK, unfortunately its only when you start looking closer you notice things you don't really want to see...



Dirty dried on oil and road gunge from the 80's probably, I've soaked it, hence the wet look...


Now the nasties...

Cracked...


Cracked sump plug drain...


Nasty gouges...


Snapped orf...


Badly scratched but I don't think it has an impact on anything...


I've got the circlip out nice and cleanly though on the inside of the LH crankcase with a view to drifting out this 6207 Bearing. I'll heat the casework 1st before attempting to drift the bearing out. Then perhaps I should decide on what to do and perhaps who to see about saving this side of the crankcase?

[stinkwheel]

If you stick it in the oven, the bearing will probably just fall out if ylou have it facing down. Does really stink the kitchen out with oil fumes though. i'm fortunate enough to have aquires a garage oven for just such eventualities. i drag it out into the garden and hook it up to the cooker socket with a long extension.

I'd get it all de-yacked first though. A paintbrush and paraffin followed by a bucket of hot-soapy water is a good tool for this.

This one looks like it already has an insert in:


Looks like you need the services of a skilled TIG welder though. That or getting really good at aluminium soldering.

[OldBoy67]

As Stinkwheel has said clean up both cases. I'm a bit suspicious about your first image - it looks as if oil has been leaking copiously from the breather union on top of the engine. If so, why?

Check that the outside race of the main roller bearing in the opposite case can be removed and has not spun in its seating. The case may have been peended to keep the race in place so beware.

A good clean should enable you to spot the major problems more easily. But I see that the yellow chromate is still present. Keep that when cleaning (or if somebody offers to blast the cases).

From your photos I can't see anything that is beyond repair but you will need a good ally welder and engineering workshop to help out. Remember that genuine GT cases are not in plentiful supply!

[stinkwheel]

Paintbrush, paraffin and patience.

[Dave the Bass]

Nice cleaning up work there Mr Stinkwheel, well done. I went through that exact same process when I rebuilt my lovely 1960 Redditch 350cc Bullet only I used white spirit and a lot of different shaped brushes to shift the grease n gunge.

@Mr OldFella, yeah, the whole top of the crankcases were covered in that mess, here's another before and after picture, guess which side I've cleaned?!


I've found more damage in a really annoying place too, deep inside the 'oil tank' compartment at the very bottom of the crankcase, its breached open. Looks like someone has either fitted too long a case screw or drilled too deep if they were trying to helicoil/rethread the fixing position on the otherside of the primary side casing...

Erks...




Its definitely breached, I can squirt WD40 down the threaded hole where the fixing would screw into on the other side and see it seeping into the oil compartment. Bum.

[Adrian]

Your 350 Bullet seems to have been almost cossetted in comparison with this one. I can see how its previous owner might have suspected that this could be an uphill slog and prioritized his other bikes!

A.

[Dave the Bass]

Yup, I agree Adrian.

Every so often I think, "bah, I'll just sell it on as a box of bits" but then I'd never get to own and ride a GT250 that I'd have hard on to get it back on the road.

And............, if Steve the CC was still around, he'd deduct a million points and I'd never achieve guru-dom on MBR!

[Dave the Bass]

From your photos I can't see anything that is beyond repair but you will need a good ally welder and engineering workshop to help out. Remember that genuine GT cases are not in plentiful supply!

A good welder may have been located, comes recommended by a chum.

RE-genuine GT Crankcases, am I right in thinking that only the GT had that small breather pipework that fits across the front halves of the 2 crankcases in addition to the huge great breather that exits just behind the oil filter housing too?

[Dave the Bass]

More pics, more news.

I've removed every stud and seal and 'things' from the LH crankcase in preparation for getting some repair work done on it. A talented/sympathetic welder may have been found, huzah. Whilst it was clean and nicer to 'play' with, I thought I'd try and see how some of the bits fit together with other random bits I've got in the box. The further I get into this project, the more I realise there are parts missing but its quite an inspiration working out how the whole thing WILL go back together one day...


Its very different from a Bullet, look at this bolt-in internal oil piping...


...and its got an internal oil filter located here...


This is the breather connector for the big bore hose that runs to the rear of the bike, it looks like its been tightened with a cold chisel or suchlike...


For some reason I have 2 oil pump housing covers, one has a hole drilled in it, the other doesn't. I have no idea why. Anyone else?