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Discussion Starter · #1 · (Edited)
Hi, I am new member of this forum and I'm building an -73 CB350 K4 that has been sleeping in an barn for 35 years. Lots of problems already solved and some issues are still available. One problem I need help is how to fix the flywheel and starter clutch?

I took off the flywheel to found out the three screws that are holding the starter clutch were separate and the screw holes in the flywheel are worn. Issue shown in the attached image. Image shows all the parts I found from the starter clutch assembly, I think I am missing some springs at least? Does anyone have an image how it should look when it is assembled or an exploded view from the assembly?

How can I fix the worn screw holes in the flywheel, can I add longer screws all the way through flywheel and attach them with an nut? Or one idea I got was to use chemical metal and drill new hole and make new threads for the screws.

Sorry my English can be a bit worse I do not talk English as my mothers language and I am from Finland.

Image from the flywheel / clutch assembly: https://imgur.com/a/sD4bKMC
 

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You know of cmsnl for the exploded views which can only help.

The flywheel is the alternator rotor, which contains the magnets for the rotating magnetic field.

The starter clutch appears to be "pegged" which you don't show in your picture.

The starter clutch/free wheel/drive unit has 3 rollers, 3 small tubes ( from memory ) that have springs in them, again which you don't show in your picture.

The alternator rotor may be salvageable with enlarged holes to accept inserts that the counter sunk screws screw into, but cost may be high. 243 euro plus taxes and carriage etc...?? just for a new rotor.......

The bike has a kick starter which works, so all is not lost and some weight saving could be done which would be easier on your pocket also.

https://www.cmsnl.com/honda-cb350k4-european-direct-sales_model16401/partslist/E11.html#.XD8I7tX7Tcs

Find your exact bike on here and have a look.

Is the starter clutch body cracked?? and how is the "gear and face" that the rollers jam onto ( sometimes called a sprag clutch incorrectly ) and transmit the drive from the starter, is it "wavy" ?
 

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mh82 welcome to the forum. This is posted in the wrong forum so perhaps a moderator can move it.

You need to find a better part, that one is non repairable if you want to use the electric starter. I would also suspect the magnets are weak from the pounding it has taken.

You also need this part, SPROCKET,STARTING
product number: 28110286010 and I would suggest a replacement starter chain.

Check the replacement parts carefully. A worn starting sprocket will have flats on it from the rollers. You can replace the rollers, caps and springs without taking the rotor assembly apart, just takes a bit of patience.
 

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The rotor damage may ( may as in possibly ) salvageable but needs machine shop operations to make good the holes for the countersunk screws and peg, so oe screws and peg can be used. It all depends on having the rotor in your hand to look and see if enough "meat" is left. The holes will be well mangled and oval, but have a look and see. If you have no access to a machine shop and lots of money, get new parts, else e bay.

Poverty in the real mother of invention, i was once told.
 

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Discussion Starter · #5 ·
The rotor damage may ( may as in possibly ) salvageable but needs machine shop operations to make good the holes for the countersunk screws and peg, so oe screws and peg can be used. It all depends on having the rotor in your hand to look and see if enough "meat" is left. The holes will be well mangled and oval, but have a look and see. If you have no access to a machine shop and lots of money, get new parts, else e bay.

Poverty in the real mother of invention, i was once told.
I think I can fix the rotor with fairly cheap money by using "screw sleeves". I just need to drill bigger hole and insert an screw sleeve with M6 inner thread diameter. Just bought the sleeves and waiting them to arrive. Otherwise I cannot see any other damage in the rotor, the magnet field seems quite strong.


Screw sleeves I ordered: Tapsert kierreholkki M6
 

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As long as you are accurate drilling and tapping and there is enough "meat" left, then this should work. Dont forget the locating pins plays a good part in transmitting drive as well as the counter sunk screws, think flywheel key.
 

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Discussion Starter · #9 ·
any pictures??

Its so much more rewarding fixing thinks thru your own efforts rather than mere cheque book engineering
Sorry, didn't took pictures after the fix. Anyhow I trilled 9mm holes and installed the thread inserts and they filled the largened holes perfectly. My starter works now perfectly.
 
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