Starter Motor

[Fiddler]

Guys,

Has anyone had any experience with a starter motor becoming weak?

Punsun is refusing to start and wont turn over with enough speed to fire and occaisionally hits compression and stops there.
At first I assumed a weak battery and charged it with no benefit. Then I wondered if the battery had lost some cranking current due to the big demands on it, so i replaced it and the same happened. Whilst I was trying to start it I noticed a whisp of white smoke from the starter, nothing much and assumed it to be just a touch of dust or carbon burning off.
Finally to try to eliminate a battery fault I put a large car battery on it with the same effect, no more smoke but not sufficient power to fire.

Ive only had starter motors fail totally before so Im a little confused by whats going on.
Any ideas gratefully received, Big Knock this weekend coming so Im keen to get this sorted asap.

Cheers, mark

[TimppaX]

Starter faulty. Maybe dirty/oiled or just worn out. Bearings?
Open and chek/clean/repair worn out parts.

[Stuart]

Wondering whether the springs that push the brushes onto the commutater are ok? If they weren't tempered correctly they'd slacken off causing those kind of probs I reckon. I'd get them out and stretch them a bit. That might put some life in them.

[andrewaust]

Hi Mark


I'm thinking of a few problems, one of them might be your solenoid, if they use crappy brass for the contacts you'll get high resistance across the striking plate, also if the metal plunger isn't adjusted correctly at the factory the same thing will happen over a short period. Now if the smoke came from the large starter body itself it could be a shorted commuter/stator winding, if your seeing white smoke that may be a sign of enamel from the windings burning.

Like Stuart said, it could also be a brush problem, check to see spring tension and also the brush guides are not jamming the brush holding it off the commuter.

I'm assuming the starter is fairly new and hasn't done a lot of work! So maybe checking that solenoid first might be a good idea.



Cheers mate - let us know what you find.



Andrew

[Fiddler]

Thanks Guys,

I think I mentioned in an earlier post that although pretty confident in the build quality of the actual lump, I had some concerns about cost cutting with the add ons on this engine. Its possible its just one of those things or maybe the starter is a weak point.
I'll let you know what i find as soon as i can drop the starter. England is currently caught in the middle of a 48hr monsoon Spannering weather outside it aint.

Cheers, Mark

[Fiddler]

Guys,

Got the starter stripped today. All looked OK and checked out fine with a meter. Feeling rather deflated I rang Mike from Portable Energy who steered me the right way.
The spot welds that hold the coil leads onto the casing are a bit suss, like a dry joint on an old circuit board, which is why they look fine but cant cope with current. Quick repair by drilling holes through them and the housing and putting a couple of small bolts in, then grinding some of the bolt away so everything can clear and job done.
Better than new Apart from the dodgy spot welds everything else looked well up to the job so fingers crossed it will be trouble free from now on.

Cheers, Mark

[Stuart]

Mark, dry solder joints can cause some bloody awful problems.
For anyone else interested about bad solder joints, the joint itself should appear silvery and reflective. Anything that looks like it's not smooth (like a minature moonscape almost) is suspect. Solder joints like this occur if the wrong temp soldering iron is used, the assembly is moved before the solder has set or it is cooled quickly (by blowing on). These joints appear to work fine first off but will stop conducting at anytime without warning. Some take considerably longer than others depending on use and current drawn.
Best thing is to use a braid to 'wick' the bad solder away and appliy some new stuff.
I've fixed doorbell, kids toys, you name it, all with dull looking joints.