Starter or bendix drive squeeling???

[garyS-NJ]

In the meantime working on an '86 and with the starter button I hear a screech under left cover and it occasionally turns the motor a bit. Starter was out and seemed ok. So we took off left cover and idler looked ok as did bendix and starter gear. .. we rotated the flywheel and it turned the crank pretty much ruling out the flywheel slipping on the shaft. Then we checked #1 @ TDC and the timing marks came to window confirming. So it's either the starter ( but the squeel is under the cover ). Or the bendix drive.. both are a pita so would like to tackle one... bike has a two brush starter and no 4 brush immediately available... bendix gear only turns one way by hand but perhaps under load it's slipping.. does a bendix drive fail like this??

[mmaleney]

Was the motor hard to turn by hand with spark plugs out.

 

Did you turn the motor CCW.

 

Did you add any oil down the spark plug holes.

[garyS-NJ]

Motor turns ok. Held the idler gears and cranked the starter watching the bendix gear and it wasn't obviously spinning wrong. Pulled the starter and found one brush hanging up bc the spring holder tab was bent. Ahah! Reinstalled starter and still no dice. Same screech At this point starter was pulling down the voltage even with a jump box paralleled.. measured voltages and jumped out the solinoid to rule other stuff out. He's ordering a Chinese 4 brush starter..

[Flyinfool]

Did you pull the flywheel to check out the start clutch?

It is common for the ring that holds it all together to have cracks in it.

look close at the surface of the start gear that the rollers in the flywheel run on, if there are any lines in that surface it is toast.

 

I never heard of a starter clutch that squealed, It usually sounds like there is a small person stuck inside of the engine with a hammer trying to get out.

Is this a bike that has not run in a long while? If so it could be possible that the oil has drained off the grip surface causing it to slip.

[garyS-NJ]

Didn't pull the flywheel yet as the 2 brush starter was loading down a new battery with jumpbox. Do they all just suck that bad?? Well i watched my bud get the brush loose but didnt look close at it or ohm it out or assemble it myself so i suspect the starter is coming in and out so fast its just rattling the start idler gear train.. odd because my 2 brush starter in my '84 didn't make that noise.. and I've never heard that noise. I i've heard that big clunking in my bike occasionally. This one didn't clunk. But what about oil on a slip surface?? Where??

[Flyinfool]

It is common for a stock starting system to feel like it is loading the battery down. The 2 brush starter is weak, its ground path is very poor, and all of the big wires on the bike are too small for the current needed.

 

A 4 brush starter will fix the weak starter issue and the bad ground path issue, or there is a simple ground path mod for the 2 brush starter that @dingy came up with. Upgrading all of the big wires to #4 welding cables will fix the undersized wire issue.

 

That did sound rather counter intuitive that you need oil of a grip surface. But then so does the clutch need to be in oil to grip properly.

 

The grip surface is part of the 72 tooth gear behind the flywheel, the only way to see it is to remove the flywheel. These bikes do not have a Bendix in them at all. The gears on the starter are always engaged with the mating gear, there is a weak one way bearing in the flywheel that grabs the 72 tooth gear for cranking and then allows the connection to slip as the engine starts. The stock setup has only 3 rollers to provide that grip, it is common for the mounting screws to come loose, the mounting ring to crack and the 3 rollers to leave marks (Brinell marks) in the mating surface of the 72 tooth gear. once you get a bunch of Brinell marks in that mating surface, it will no longer work correctly. If all of the oil has drained off of all of these parts due to being parked for years, it is possible that it is not working correctly.

 

Member @Dano makes a replacement with an 18 roller one way bearing that is pretty much bullet proof.

 

ps

Pulling the flywheel for the first time is always fun. There of some great stories around of the experiences.

[garyS-NJ]

Good stuff thanks on the one way gear. That starter with a new agm batt was pulling the voltage down enough to warrant replacing as i cant see the dingy ground mod doing enough or worth the effort. & bought heavy cable and lugs to redo my starter cabling but after the 4 brush went in, she starts too easy... &so with that we might still be pulling the flywheel. That is a normal right hand bolt thread correct??