1972 Honda CB350 - Starter clutch slipping

[flracer3]

So, my 1972 Honda CB 350's starter clutch is slipping.
The bike won't start at all. I've tried kickstarting; tried push starting; obviously tried through the starter switch; and even tried the "tap a hammer on the engine while trying to start" trick and nothing is working. I would love to hear any recommendations or advice of what to do.

While I'm still somewhat of an amateur on repairing bikes, I'm not afraid to get my hands dirty.
Just recently I reinstalled my right carb as it was coming out of the intake boot; replaced my spark plugs; adjusted my cam chain cause the timing was off; had help adjusting my values; etc.

Thanks in advance.

 

[SONICJK]

I have the parts for the starter clutch id let go of. It's an easy fix.
Send me a pm

 

[Rude Boy]

Hey flracer3, welcome to DDT.
So basic questions first;
Did the bike run before you replaced those parts?
Did you gap the new spark plugs properly before installing them?
Have you checked: 1) Spark 2)Fuel Supply 3)Compression 4) Timing [ya sure its correct?]


What makes you think its the starter clutch? You definitely want to make sure the above ^ is in order before breaking into the starter clutch.

 

[flracer3]

Thanks for the quick replies so far.

@Sonicjk. Awesome. I might take you up on that if it turns out that's what needs to be done.

@Rude. No. The bike wasn't running before I replaced those parts. Once I replaced everything it was running great. Then I let it sit for about 2 weeks (I was outta town on vacation) and now it simply sounds like the starter clutch is slipping. Also, yes, I definitely gapped the new spark plugs. Lastly, yeah, right before my 2 week vacation, I brought it up to a local shop for them to check/review my work. I know for sure they checked the spark plugs; fuel supply; and timing. Not sure about the compression though.

I should say that it sounds like it wants to turn over sooo badly (as though everything else is functioning perfectly). It simply makes this horrible noise when it sounds like the starter clutch is slipping.

Thanks again!

 

[SONICJK]

So it's like a squealing noise and the starter is turning?

My last bike did that too and needed the starter clutch repaired.

 

[Rude Boy]

haha ok good.
Compression isn't that big of a deal, if the bike was running that shouldn't be the problem (You should check it soon if you get a chance, its good to know + check every few thousand miles or so, preventative maintenance)


How would you describe the sound, high pitch squeal? Do you hear a sort of honk?
I cant understand why a starter clutch would go bad from sitting for two weeks , but I don't know much about that part.


This thread has started me think that a cb350 of mine may have the same problem...

 

[flracer3]

Its definitely a squealing noise with a honk. I called the shop where I had them check it out and it turns out that they thought that the starter clutch might need replacing (thanks for the heads up!). Anyway, does anyone have any advice on how to do accomplish this repair (being a novice and all)?

 

[SONICJK]

It's really simple.

Pull the side cover.
Remove the starter.
Remove the starter chain.
Get the correct size bolt (I dont remember M12 fine thread maybe?) and screw it into the stator rotor until the rotor pops off.
Once the rotor is off you can get to the springs and caps. Most likely your caps are worn out. They will need replacing. I have a good set if you need them.

 

[wibblee]

Hi,

I was wondering if you'd had any success with this problem. People always say "fuel, compression and spark" and I seem to have all three, (compression was just with the "thumb over the hole" test) but it still won't go. (it never has while I've owned it)

New points, condenser, coils and plugs and the spark looks good. I did the timing and got everything to spec.

If the starter clutch was the answer, I'd like to hear more about the "honk". All the starters squeal, don't they?

Thanks,
John

 

[Frankmowthelawn]

There's an over-running clutch between the crankshaft and the alternator rotor where the starter gear is located. There are three springs with little buttons over the springs holding rollers in tapered slots between the crank and alternator. When the starter is engaged, the alternator is being driven by the starter by a chain and the rollers lock the alternator and the crankshaft together turning the engine over. Once the engine starts the engine is running faster than the starter will drive it and the rollers release and just roll on the shaft.

A squeal could be the starter shaft vibrating in it's bearings, the chain slipping on either of the chainrings or the rollers slipping between the alternator and crankshaft. Remove the cover and try starting the engine while you watch and listen. Make sure your battery is fully charged. Expect a little oil to drain out when you remove the cover, that's OK.

My CB350K4 did the same thing when I got it. I pulled the alternator rotor and replaced the springs and never have had another problem with the electric starter. I generally use the kickstart but have full faith in my starter.

Regardless of all of this, push-starting your bike should get it runing. Concentrate on getting the five required things for an engine to run correct before you worry about the starter. They are fuel, air, compression, spark and getting them all at the proper times.

First things first; do you have a maintenance manual? They are available electronically here on the forum. Get one and read it closely in the areas of tuning, timing, valve adjustment and fuel systems. Start with your valve settings. Get them perfect or everything else is wasted effort. They can affect your compression too so be sure!! Next is your spark timing. Get that right. Not close, get it right! It's really easy to time your engine 180 degrees out of timing. Make sure your sparkplugs are firing too because the coils, condensers or wires could be defunct. Make sure you are getting fuel to the carbs.

If none of that fixes the push start problem come back and bitch about it and we'll get you through it. Everybody here that has one has had problems with their 40 year old bike and as simple as they are, it's amazing how tough they can be to keep running!!!

Endeavour to persevere!

FMTL