Ironhead Starter Grind

steve-o- · #1 12th May 2010

Haven't posted in a loooong while. Picked-up a '74 last fall (mostly complete, nearly running). Forum has been invaluable this winter. Bike is still not complete but now fires and runs. If I hit the start button in short "pulses" or "bursts" , I can get it going. If I hold the start button, the engine will turn, stop and then grind. I've got the pimary open and the complete starter drive assembly removed (new starter and solenoid installed). I cannot see anything physically wrong. Any suggestions? I'm getting to the point where I need to get this bitch out for a ride to rekindle our relationship.

tracbike · #2 12th May 2010

Make sure battery is fully charged and sometimes the "Timing" being off will give you that result. Possibly to far advanced.
Check weights make sure they move and static time it.

spdtrux · #3 12th May 2010

make sure the solenoid is spaced right. i put a new solenoid on my bike with the stock spacer and had a similar issue. threw a washer on bothe screws and a homemade cork gasket and wala no grinding or other noises and no leaking.

if everything else is bolted up right. this might be worth a shot

steve-o- · #4 12th May 2010

Threw the charger on and will check voltage when fully charged (probably drained it quite a bit trying to start yesterday). Will check timing tonight. Upon initial inspection it appears to be pretty advanced. The solenoid and spacer both had a number stamped into them, 3A I think, so I assume the the throw is correct. THNX

72Iron · #5 12th May 2010

I would suggest two things. A new bendix, and a new detent spring on the solenoid plunger.

75 Iron · #6 12th May 2010

Its the bendex gear. just went through it with my 75....

steve-o- · #7 13th May 2010

I thought bendix too. Would it look chewed-up? I tore the shaft down and had a look, cleaned it all up and re-assembled. Nothing looked messed-up when I had it appart. Maybe another is in order. THNX

BLIGHT · #8 13th May 2010

Quote:

Originally Posted by steve-o-

I thought bendix too. Would it look chewed-up? I tore the shaft down and had a look, cleaned it all up and re-assembled. Nothing looked messed-up when I had it appart. Maybe another is in order. THNX

I replaced the Bendix on mine, but I made the bone-headed move of hitting the starter with the primary cover off to check the action.

The solenoid engaged, and ended up bending the jackshaft as the pinion gear tried to crawl around the ring gear. The jackshaft needs the outside-end support provided by the bushing in the primary cover. Dumb mistake that I'll never repeat!

Anyway, the Bendix was slipping and making a grinding noise and not turning the engine over.

New Bendix (and jackshaft) and she starts nicely now!

Cheers,
BLIGHT

steve-o- · #9 13th May 2010

I don't know when I'll get a chance to tear into it again (family commitments) but I will take a good look at everything and throw a new bendix at it. Hopefully that'll be the fix. Blight...bad story...but good heads-up to anyone messing with the starter. THNX again to everybody for offering up advice.

75 Iron · #10 14th May 2010

Quote:

Originally Posted by steve-o-

I thought bendix too. Would it look chewed-up? I tore the shaft down and had a look, cleaned it all up and re-assembled. Nothing looked messed-up when I had it appart. Maybe another is in order. THNX

The gear would not look chewed up. Its not the teeth on the gear its self but what make them turn like a centrifical clutch. I replaced every thing else and still had a problem, the bendix gear was the last thing and it was the problem.Good luck. Let me know what happens.