Narrowcase kickstart

[ranton_rambler]

Here's my chewed-up kickstart shaft. The bike is a 175TS 4-speed. Having started looking for a replacement, it seems they are quite hard to find. But there are a few similar ones on eBay, but with 8 teeth on the quadrant rather than 10. Is this a later version? Can I adapt to fit mine, presumably with some other parts?
From photos it looks like the inboard trunnion is bigger on the 8 tooth version.
I've read about converting from the leaf spring arrangement to a coil spring. Is that a worthwhile modification?
I think the ratchet and corresponding gear teeth look OK.

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[KarstenH]

have you seen this?

https://www.ebay.de/itm/Ducati-250-350- ... 0005.m1851

http://www.ebay.de/itm/Ducati-Bevel-Sin ... SwmFpZtxKV

Karsten

[ranton_rambler]

I have seen those, but mine is a different type. Similar but inboard trunnion is smaller and with 10 teeth on the quadrant gear. I will look at some parts book to understand more....

[double diamond]

The ratchet teeth on your kickstart gear look good but how are the teeth that engage the kickstart shaft? By the looks of your kickstart shaft gear, I would expect the ratchet gear would also be damaged. It may have been replaced though and the kickstart shaft not.

The ramp on the retracting plate is worn. It shouldn’t have that step in it.

I have a number of odd dimension kickstart shafts that I do not know what Ducati they fit. None are tagged with part numbers. If you would provide dimensions or detailed pictures of the shaft you are in need of, I would be glad to check my inventory.

Matt

[ranton_rambler]

The mating gear teeth are OK, and ratchet teeth look good on both halves. The bush that supports the kickstart shaft in the right-hand case has migrated out of position and got chewed up by the first gear on the other side, so I don't know if that has led to the damage to the teeth on the quadrant or vice-versa. Apologies for bad photo but you can see that the bush has moved.
Is the bush retention a known issue? With a known cure?
I have started to look for a replacement shaft, but it seems that the 4-speed type are hard to find. I have a possible one in USA which the guy is going to dig out for me and measure. I think my part number is 0600.07.110 and his is 0603.07.110 he thinks.
If you have one it would be great. Mine is 138mm overall length. The inboard trunnion is 12mm diameter, 18mm long. The shaft outboard of the quadrant is approx 18mm diameter with a smooth section about 32mm long after the spline, and then a rough-turned section. 10 teeth.
I was trying to find some parts book information today to work out if I could fit the 5-speed type. These seem easier to find so far. I think I would need to change the gear too, and bore the case to take a bush to suit the bigger trunnion (14mm?), but not sure if the ratchet teeth are compatible with my first gear.

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[double diamond]

The kickstart shaft bushing can become loose in the case. It appears that yours may have been pushed in by improper installation of the kickstart shaft. The trunnion is not a long as the bushing in the case. It looks like the bushing was pushed in the length of the trunnion. Or, the bushing may have shrunk due to action of the kickstarter, become loose in the case and migrated inward. Actually, the condition of your kickstart bushing is fortunate. The case is often broken in the area that supports the bushing. This is common on 250 and 350 NC engines. Perhaps 175’s are not afflicted in this way as they don’t kick back with the force a 350/350 can generate. You’ll probably need a new bushing with proper interference fitted. There isn’t a “cure” as such; all you can do is bring the interference fit of the bushing in the case back to specification. This will require splitting the cases. Looks like your engine needs a good internal cleaning anyway, so splitting the cases would be beneficial.

I’ll have a look this weekend and see if I have a kickstarter shaft that matches the dimensions you have provided.

[ranton_rambler]

Cases are already split, although I've not completely removed the gearbox internals. Trip to work next week for a dunk in the parts washer and then we'll decide whether to get them aqua-blasted.
I thought about making a new bush with a little lip, and adding a matching counterbore to the case.
May have found a shaft on US eBay but will wait to hear from you. Plenty else to keep me busy!

[double diamond]

Check your PM for the kickstart shafts I've come up with.

Matt

[EMZEDDER]

I had same issue with my 5 speed Mototrans, the shafts and meshing gear differ (as I found out) and can be very hard to find the correct item. I do have a shaft, if you PM me all dimensions I will check this out. My engine has an extra large bush with top hat section which spread the load maybe. I fitted a decompressor to avoid kick back which seems to be the culprit.

[ranton_rambler]

I have one on the way soon from Matt on this forum, but thanks for the offer.

Ian