Topic: 75 550 electric motor gear catch

[Tews19]

I got to working on the electric start motor. I pulled it and the gear spins. It moves forward and backwards.the gear I'm talking about is in the engine itself. The electric motors teeth catch it and spin this gear to start the bike.  I then pulled my other 550 motor out and that only spins in one direction inside the engine itself. Now to fix this will I have to split the cases?  If so I'm going to leave it as is and not mess with it.

[Tews19]

Pic of this gear in the engine.

[Tews19]

The metal shaving are from the screws. The impact gun tore up the cover screws. Not the engine itself

[Stev-o]

Dont think it should spin both directions. Is it #44?

http://www.westernhonda.com/fiche_section_detail.asp?section=2450209&category=Motorcycles&make=Honda&year=1975&fveh=131064

[Tews19]

I'm not sure.

[Bodi]

That's #46. It should turn only one way, driving the primary primary shaft #3 through the one-way starter clutch #48, 49, 50, & 77.
I don't know if you can service this through the sump hole but it would be a bunch easier with the cases apart.

[Tews19]

I'm pretty sure that might be the wheezing noise. I thought it was the cam tensioner but I adjusted that when doing the 3k tune up. I think this will be my 650 engine swap. Bummer as she idles awesome , shifts super smooth. Hmm. Maybe save it for the paulages build.

[dave500]

it can be done,ive done it and so has xsmooth here.
http://forums.sohc4.net/index.php?topic=121832.0
he then did a good write up with great photos so you can see if you want to tackle it?
http://forums.sohc4.net/index.php?topic=122084.0#lastPost

[MiGhost]

The wonderful PITA starter clutch. It is a sprag clutch that turns free one way, but locks in the opposite direction. They ususally get damaged by the engine firing, but not catching fully. Then the starter clutch reengages with a sharp impact.

If the starter cranks. Then spins free. That would be the indication that the springs, caps, and rollers need to be replaced. Otherwise I would not mess with it until you need to split the cases.

If you do pull it. Check the clutch outer to make sure that there are no cracks around the spring bores, and that the springs do not push through the outer wall.

Alternate spring number: CB650
28125-426-000 SPRING, STARTER CLUTCH ROLLER

[dave500]

it can be damaged by attempting a start then releasing the button before the engine fully fires,then pressing the button again before the spinning engine has come to a complete halt if it didn't start or half started,as the engine stops it may roll backwards a little on the next compression cycle just when you thumb the button again?

[MiGhost]

it can be damaged by attempting a start then releasing the button before the engine fully fires,then pressing the button again before the spinning engine has come to a complete halt if it didn't start or half started,as the engine stops it may roll backwards a little on the next compression cycle just when you thumb the button again?

True!
The impact of it reengaging is what causes the damage.
Same thing. Just worded differently.

[dave500]

just out of interest its not really a spragg but got nicknamed,its a pinion and plunger type.

[Bodi]

No. This is emphatically not a pinion and plunger drive. That system of starter drive moves the driving gear axially to engage/disengage the driven gear - common on cars where normally either a Bendix or pinion & plunger drive are used: both retract the starter motor gear from the flywheel ring gear after startring.
Although calling it a sprag clutch is incorrect, many mechanics use this term for them.
Technically the Honda SOHC4 starter clutches use a "trapped roller" design, with the starter gear train always engaged.
Damage to the clutch can be caused by re-engaging the starter before the engine stops. The three rollers retract against their springs by centrifugal force due to the primary shaft rotation. If the starter motor is spinning while the primary shaft slows down, one roller will always come out of its pocket first: engaging only one roller produces an extreme radial load on the clutch outer housing. This also happens if one or two rollers are gummed up and don't engage properly on a normal start.
Depending on the clearances and wear, the radial force can misalign the housing and gear enough for a roller to pop out or a spring cap to jam or pop out. Once one roller is gone the clutch will soon fail completely. Cracked outer housings are common in this situation.

[Tews19]

So the consensus is to stop riding it as it stands to stop further damage??Well I will check out your thread and xsmooths. Thanks to all for chiming in.


EDIT: Do I stop riding it or will it be fine for the time being?