[Graham B]

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Thestory so farin this sorry tale.

The problem is that when hot, the starter motor won't turn the engine. It tries but just hasn't got the umph! So (and some of this was for other reasons) I've;

• Bought a new battery.
• Serviced the existing starter motor.
• Changed the starter clutch.
• Changed the lead from the solenoid to the starter.
• Checked the earth lead and cleaned up the contacts.
• Bought a GL1000 starter motor and serviced it.
• Tried a spare solenoid.
• Started to drink heavily.

The motor cranks the engine like there's no tomorrow when the engines cold.

So, before I turn into a drunk, where to now?

 

[Graham B]

imported post

PatinIdaho wrote:

Timing to advanced?

Pat

It's an idea but as I understand it, the timing is fixed and can't be adjusted.

Tickover is fine as is the pickup when I open the throttle. There's no odd noises when I snap the throttle shut either.

Spark plugs look a good colour.

 

[Graham B]

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PatinIdaho and exavid, you might be on to something :clapper:

This morning I cranked her up from cold - no problem. Warmed her up until the fan cut in. Let the fan do it's stuff and then switched off.

Switched back on again, pushed the button and "clunk". Turned off the kill switch, pushed the button and she spun. Turn the kill switch on again while the starter is still spinning and she fires up fine. :baffled:

Tried it a number of times and different ways. Now sometimes the motor turns without killing the ignition. Could be the new brushes bedding in but I don't understand how it could be ignition. I did change the timing belts a while ago but was very careful to make sure everything lined up properly and I've done this a few times over the years. Spark plugs are standard.

So, if it is ignition, where to now? :baffled:

Twisty, thanks for the link.

 

[Graham B]

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Exavid,

Combustion chambers are fine. I know that because I've recently had the heads off to change the head gaskets that weren't blown (Water pump gone instead).

Spark plugs are NGK DR8ES-L. Took them out after a run and they looked perfect.

I have to admit I've not timed how long before things work again but I'd guess around half an hour.

Need to check the advance/retard unit but not too keen on taking the engine out (again) to do it umpkin:

 

[Graham B]

imported post

What bothers me is that this is the second starter motor to exhibit the exact same problems. The latest starter motor is a GL1000 one which, I'm told, has a bit more power - it's certainly bigger! I have to remove the exhaust and he nearest stud to get it in (Of course, the nearest stud had to be the one that didn't want to come out). I've also tried another (known good) solenoid to no avail.

Just checked the vacuum advance unit by simply taking the vacuum pipe off the carb and sucking. There is a reassuring "plop" from the unit as I suck and let go. No idea of a simple way to check the manual advance. Guess I'll have to borrow a strobe and see if it all works as it should.

It might just be the brushes need bedding in and I'm paranoid :gunhead:

 

[Graham B]

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I've been chatting with a local friend. It's looking more and more like the manual advance being stuck in the advanced position.

Thanks for everyone's suggestions. I'll give them a try as they will help prove/disprove the manual advance theory and I'd like to be 99.99% certain before I start pulling things apart (again). :clapper:

 

[Graham B]

imported post

I can say that the cause of the problem has been identified as the manual advance - I just can't get to it at the moment.

The way I get around it is to turn the engine kill switch off. Even when hot the engine will spin with no trouble at all. When it's spinning simply click the kill switch on and the engine bursts into life.

Works 100% of the time - just not sure how long the kill switch will last :?

Good luck.

 

[Graham B]

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exavid wrote:

Not a manual advance, I think you're referring to the vacuum advance not dropping back, stuck in the advanced position. That sure would do it.

Sorry, I mean the manual advance. There are two elements to the unit. Haynes manual ATU section page 111, section 5 point 2 refers.

I didn't know about it until Iwas shownit on a dud engine out of it's frame.

 

[Graham B]

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That's the one. It's a right b(*&^r to get at with the engine in the frame. Dead easy when it's out :?