MRC Forum- brought to you by www.morini-riders-club.com

Hello from NZ!

I’ve recently rebuilt an '81 350 Kanguro engine and just fitted into the bike. Everything seems to work beautifully as it should EXCEPT for the gearbox.

Whilst it shifts up through the gears nicely, when chopping down, it becomes incredibly vague and often requires several prods to get it to change with lots of false neutrals in between.

The linkages are all adjusted up correctly and the clutch is behaving as it should.

Having to pull the engine out and apart again is such a pain, but before I do, I thought I’d put it to the forum. Ideally, I’d order any parts needed before I start disassembly, since ethane I can hopefully do it all in one go!

I suspect it might be a weak return spring? But any thoughts would be hugely appreciated!

Thanks!

Hi, I would double check that the linkage/lever isn't the problem because of play/adjustment; touching footrest, frame etc or even the rose joint twisting and limiting movement when changing down

Good luck

Was the 'stop' removed from the gearbox? This needs to be setup.

As mentioned above, linkage adjustment can cause these sort of symptoms, but assuming all is ok here, as Mike says, the stop plate in the gearbox needs setting when the cases are apart, as described in the blue book.

The spring can jump out of its groove when mating the crankcases too so sometimes it is just unfortunately a case of splitting the cases and putting it back again.

Finally, you don’t say whether this issue is when riding or statically on the bench. I once had issues checking for good gear engagement after a rebuild and pulled the engine from the frame only to find no assembly issue and the same happening once I’d put it back together again. Eventually I decided just to see how bad it would be when ridden and it was a lovely gearbox with never a missed gear. I think the dogs were hitting eachother face on and without the engine turning just didn’t want to go home. Now when I check gear selection on the bench I rotate the input shaft whilst providing some drag on the output shaft- but it’s a bit of a 3 handed job!

morini_tom wrote: ↑23 Jan 2023 18:09 Finally, you don’t say whether this issue is when riding or statically on the bench. I once had issues checking for good gear engagement after a rebuild and pulled the engine from the frame only to find no assembly issue and the same happening once I’d put it back together again. Eventually I decided just to see how bad it would be when ridden and it was a lovely gearbox with never a missed gear. I think the dogs were hitting eachother face on and without the engine turning just didn’t want to go home. Now when I check gear selection on the bench I rotate the input shaft whilst providing some drag on the output shaft- but it’s a bit of a 3 handed job!

THIS.

The rebuilt Forgotten Error 350 engine was so hard to change gear 'on the bench', on a trial assembly, that I wondered if the stop plate was not positioned correctly. Decided to go for it and it was fine.

If you put a 350 in to a 2C 250 with standard 250 exhaust system one gotcha can be the linkage hitting a pipe.

I had a touch of gear selection issues once but after living with it for a short while discovered my linkage was just contacting the cover. Rectified by adjustment. I should have known better.
John