Wanted for experiments: Kokusan Starter and LH casing, etc.

Wanted for experiments: Kokusan Starter and LH casing, etc.

Postby julianharty » 18 May 2017 20:11

I'm investigating how to fit the modern starter motor such as those on the New York models with Kokusan electrics. I don't know who actually made the starter, so I'm calling the kokusan one - I'm happy to correct the description when I know better.

Anyway, I'm investigating how to fit the starter motor into a 3 1/2 K1 frame which already has my old New York 501cc engine and exhaust system (which was a challenge to fit too). I'm toying with several ideas, including offsetting and/or relocating the starter motor. I've currently got one complete set of Left Hand casing, all the gears, etc. and the starter motor. I'd love to obtain at least one more casing and perhaps another starter motor to allow me to experiment more boldly. Also I don't have any lathes or milling facilities, or aluminium welding so I'd appreciate recommendations for people who might be able and willing to do the necessary mods once I've come up with what seems like it might work.

If you're interested in following along, please let me know either by PM or simply by responding here.

BTW: I do have a copy of the article (in German) from La Strega issue 114 which details how someone else fitted the starter motor in the pre K frame (which just about has space for the unmodified casing). I've also seen a photo of a machine that was at the French Morini rally this Easter (2017) again a pre K frame was used.
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Re: Wanted for experiments: Kokusan Starter and LH casing, e

Postby hombre » 18 May 2017 23:48

I have one of those leftside covers, but no other Kokusan-parts. pm me if you're interested!

Regards, Hans
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Re: Wanted for experiments: Kokusan Starter and LH casing, e

Postby MickeyMoto » 19 May 2017 06:06

Hi Julian,

I was informed that all that is needed is to modify the nearside mounting. The cut is to the bolt hole not the frame itself. A modified plate is then used.

Your starter for 10?

Mike.
-------------------------------------------------------

Mike.
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Re: Wanted for experiments: Kokusan Starter and LH casing, e

Postby julianharty » 19 May 2017 12:22

Mike,
the K frames have a kink in them that brings the downtubes much much closer to the front of the engine, so the starter motor can't fit 'as-is' even without an engine plate on the left (to be clear people make a custom plate, as per the article in the German magazine which goes into lots of detail). I've toyed with replacing the downtubes which would allow plenty of space but risks weakening the chassis and also the bike would need to be checked formally to make sure it's still roadworthy according to UK law. The check is known as MVSA
https://www.nidirect.gov.uk/articles/mo ... sva-scheme and there is/was a points scheme where 5 points were for the unmodified frame http://www.mankymonkeymotors.co.uk/foru ... ic=13282.0

So I could take my engine and fit it to an older frame (pre K frame) where it'd fit with modified engine plate(s) and perhaps more fettling, however I'm trying to avoid doing so. From taking the starter motor off my LH casing I'm pretty sure there are other ways to make everything fit in a K frame, and thankfully the starter motor is trivial to remove and refit so could be fitted once the engine is in the frame with whatever other mods are needed e.g.
    * extending the starter motor shaft (it ends in an integral 9-tooth gear
    * using a pair of gears directly, or a toothed belt, to relocate the starter motor - perhaps a bit higher than the original
    * modifying the LH casing to rotate the location of the mount to another location where the 9-tooth gear can still mesh and drive the larger intermediate gear that's in the gear train leading to the primary drive.

It's for the last of these ideas that I'd like a spare LH case, since it'll need cutting and rewelding. I'll also need to remove any chrome plating from the casing (the New York's have them chrome plated). 30 years ago I could have wandered to one of many small machine and welding shops and asked them to help. Sadly these people are hard to find, at least near High Wycombe where I live.
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Re: Wanted for experiments: Kokusan Starter and LH casing, e

Postby MickeyMoto » 19 May 2017 13:08

Hi Julian,

Teach me to read properly. The advice was, of course, for the early frame.

Another option could be to mount the motor under the engine. Need looking at but would not affect cornering clearance.
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Re: Wanted for experiments: Kokusan Starter and LH casing, e

Postby julianharty » 19 May 2017 20:16

No worries, I've also learned to repeat key points in my communications as many of us don't read the entire text so you're not alone. I'm fairly convinced the motor can be relocated in front of the engine rotated around the intermediate gear it drives. Apart from the fairly obvious "working out where it should go" the main challenge for me is the fairly precise work that'd be required to cut the current casing to preserve the relevant mounting points (which consists of three 6mm allen bolt holes) and it's relative position to the centre of the gear it engages with, and then welding that in the new location. Anyhow, I'm hoping that between us (and the assistance of someone who can make the modifications) we'll come up with an elegant solution. I'll write it up as best I can so anyone else can make a similar mod.

Thanks again for contributing ideas.
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