gs550t with likely dead starter - preferred replacement?

[sacruickshank]

The brushes from the Triumph fit fine in the Suzi starter, which now spins nicely.

One question for those with more experience, is there any reason to avoid a light coating of grease in the shaft that sticks into the end cap, i.e. the opposite end of the spline shaft that engages the gears in the engine. I want to keep it spinning smoothly, but not sure if grease might mess up the electricals.

Thx

[Grimly]

Not 100% sure in my recollection of these specific starters, but it's common for that bush to be made of sintered bronze which has the property of absorbing oil and providing many years of lubrication when it's sitting in its own little enclosed space.

[sacruickshank]

UPDATE#N - Brushes from the Triumph starter fit well within the Suzi starter. Starter works when tested off the bike using a clamp and jumper cables from the battery.

But ... when I install the starter in the bike and send in the juice, you can hear freely spinning gears but not the pistons being cranked. All the gears are meshing correctly, so I did one test with the LH cover off. Low and behold the starter motor is turning CW when looking at cyl1! Could the Triumph brushes have an opposite polarity and cause the motor to spin CW? It's a three gear system, so the crankshaft will turn in the same direction as the starter motor.

I didn't take off the rotor or starter clutch. Could it have snapped? Should the large gear on the starter clutch be able to freely spin CW but not CCW?

Going back to my earlier pick, the brushes and power are in different relative locations. Would that make the starter spin in the opposite direction?
PXL_20211111_222404583.jpg

[Grimly]

Yep, the way to reverse a DC motor is simply reverse the polarity, and that's what's happened there.
It should be possible to find a brush plate that duplicates the original.
Try Stockers for a replacement.

[Redman]

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Going back to my earlier pick, the brushes and power are in different relative locations. Would that make the starter spin in the opposite direction?

Yes. Good troubleshooting, and good observation.

One brush has the positive power, and other brush is grounded.

Looks like maybe can move the positive brush just by putting it in the other. To move the grounded one would need to see if can find a way to ground that wire there on the other side.

or clean up original holder and see if better brushes fit.

or get brush/holder kit from Stockers

[Redman]

	Repair Kit - Denso Type: New Replaces: Denso Stockers #: RBK-4S Retail Price: $44.95 Your Price: $29.95	Repair Kit For: 2-Brush Denso Starters
	Brush Holder - Denso Type: New Replaces: Denso Stockers #: ND-L Retail Price: $32.95 Your Price: $21.95	Brush Holder Assy. W/Brushes Used In: 2-Brush Denso Small Engine Starters Repair parts : Brushes only use B-4
	Brush Set - Denso Type: New Replaces: Denso Stockers #: B-4 Retail Price: $10.45 Your Price: $6.95	Brush Set for 2-brush Denso small-engine starters - Click More Info to view applicationsFits: Denso Repair Parts Specifications: • Lead Length: 80mm • Length: 13mm • Thickness: 5.8mm • Width: 8.9mm

[Rich82GS750TZ]

As I understand (I don’t, really), earlier Triumph models were positive ground. Maybe I misunderstand, that’s highly likely. Or maybe the model this came from has one less gear in the connection to the starter clutch.

[sacruickshank]

I ordered the repair kit from stockers, only $8 more than the brush plate alone and provides the o-rings, bearings, and oil seals to freshen up the whole starter. Plus my solenoid was shot (had to jump across the terminals with a screw driver), so I needed one of those as well.

[dorkburger]

Are you sure that the solenoid is bad? Is it getting power when the starter button is pushed?

[sacruickshank]

Are you sure that the solenoid is bad? Is it getting power when the starter button is pushed?

Didn't check that. It had been working recently, with an audible "thunk" whenever the starter button was pushed. The bike has been on the lift in my garage for far too long now, so I don't see how the starter button could suddenly fail. I'll check that, but the solenoid has already been ordered.

[Redman]

. . . . . . I don't see how the starter button could suddenly fail. . . . . . . .

Other possible problem of why the solenoid doesnt "thunk" is the clutch lever switch (called "interlock" on schematics), or the solenoid not being grounded.

[sacruickshank]

Other possible problem of why the solenoid doesnt "thunk" is the clutch lever switch (called "interlock" on schematics), or the solenoid not being grounded.

Mea culpa ... Yep, the real reason the solenoid wasn't thunking was grounding. The various ground wires were still loose from when I moved the airbox to remove the carbs. Doh!

Now I have a spare solenoid.

BTW, the starter kit listed earlier in the thread was good, but there was a gap between the positive pole bolt and the hole in the starter's housing. On the OEM unit there is a plastic sleeve that fills the gaps, but this was not part of the replacement and I couldn't re-use the black plastic plate from the OEM unit since the shape of the brush insert was different. I know that's vague, but I didn't take a sample pic and it's installed now.

With the new&correct polarity brushes installed, the starter now cranks the pistons as it should. Now to re-install the carbs and hopefully we'll get a valid test start today