750 twin starting system

Hey all!

Why is it that the 750twin starting systems suck? I understand that I am working with older bikes here, but my 550 starts so much better at the same age.

Is this a known problem? What is my fix here? I'd hate to have to change out the starter motor, but if I gotta I gotta.

Is it the Stator that is mentioned in the other thread?

I'm about ready to buy a new bike due to frustration, heavens forbid.

Is it your starter's not turning or is it the starter clutch? The clutch goes out on the 750 twins instead of the starter motor most of the time. Also some people report that the bolt that holds the clutch assembly and charging system mag can come loose especialy if it's been off before and not tourqued down to the right specs.

If the starter motor is not turning, I would check the relay first.

Just remember you've also got a kickstart if you need it.

Shaner wrote:

Is it your starter's not turning or is it the starter clutch?...

Got to be the starter clutch. It's dead on one of my 750s and dying on the other.

Repair kits are very hard to find now.

Kick!

The stator is part of the charging system, and not a common problem.. The problems I have seen with the starting system are:
(1) The three screws holding the starter clutch to the rotor broke.
(2) Starter clutch slipping
(3) teeth stripped off the starter clutch sprocket, causing the chain to come off and trash the stator.
(4) The starter itself was bad (probably bad brushes, or just dirty, but I just swapped the starter).

The 750 twins start so easily, (if they are just halfway tuned), that I really don't place much importance on the starter working, I usually kickstart them even when the starter works.

steell wrote:

The 750 twins start so easily, (if they are just halfway tuned), that I really don't place much importance on the starter working, I usually kickstart them even when the starter works.

I guess that could be it, but my LTD was in pretty good tune, and it still was a problem. Slow cranking with a fresh battery. Would do what i could with that (at the detrement of my battery in the long run, and then a few kicks and it would start.

The 79 is a different story, exhaust leaks, and front firing tune is giving it issues. just havent had time to tackle it other than displace aggression on the kick, rub my head, call it shite and walk away more frustrated, minus a couple calories.

IMHO, the best starting aid is an electronic ignition from a KZ440 bolted on the 750 twin

If the carbs are just somewhere near right, and the timing and points are set right (with a good coil and plug caps) it should start easily on two kicks cold.

When I first aquired my 80 750G twin, it would start instantly, and it was only running on one cylinder

If you have the original coil, then I'd consider replacing it, as it's getting pretty old.
I'm using an original coil from a 79 KZ650SR right now, as soon as funds permit I'll upgrade to a Accel coil.
And I really ought to get off my butt and convert it to electronic ignition

If you can limp it to Bucktown, I could take a look. If it needs an ignition we might try an HEI conversion with points. If it needs a coil, I might be able to dig one up somewhere, or we could try to scavenge one from your 550 as a test.

Post edited by: loudhvx, at: 2005/10/27 21:31

In the case of my 76 750 B it would do all the things a starter with dirty connections etc. would do. I was intermitantly chasing this problem around since I bought the bike. I did what I could to fix the problem without having to spend any money on it. I didn't really care that the starter was acting up because it started fine with the kick starter. While trying to start it using the starter one day, the starter cable burnt in half.
I changed the cable, rerouted it to what I thought was an ok place and it has worked perfect ever since.

loudhvx wrote:

If you can limp it to Bucktown, I could take a look. If it needs an ignition we might try an HEI conversion with points. If it needs a coil, I might be able to dig one up somewhere, or we could try to scavenge one from your 550 as a test.<br><br>Post edited by: loudhvx, at: 2005/10/27 21:31

I'll see what I can do about this. It's superkewl of you to offer this up. Pulling a coil off the 550 shouldn't be a problem. Infact, I have the two from the 620 motor sitting out right now.

Can't make guarantee's, life is a little hectic. Currrently torn btween moving into a cave or a monastery. Leasat in the monastery their'd be good beer (the one I'd choose), in the cave - no religion.

My Twin, had starter problems till I cleaned the Commutator( area where the brushes touch) while there I also upgraded the cable to 4 gauge w/ soldered ends, never had a problem out of it since. And for the starter rebuild kit I've saw them just yesterday at this [ul=https://www.partsnmore.com/cat_index.php?model=kz750&category=engine]Site[/ul]. just $30.00 not bad for parts that are hard to find.