Honda Spree and Elite 50 Forums

My first Gyro came with a bad starter, and even 12+ years ago they were somewhat rare and expensive vs Spree/Aero/Elite starters.

Of the scooters folks are interested here, only the 84-85 Spree, the 1984 NN50, and 1985-86 TG50's had no kick start. For the Spree,
many swap in the kick-start from a later model. But for us Gyro fans, a working e-start is a must.

There's much which can be done with existing starters in the Honda family, as well as parts from outside the Honda line.

The starters we are interested in were built by Mitsuba with the series name SM-10. That family of starters has parts interchange within, as well as expected difference which made them unique to each Honda Model.

-- SM-10 starter Visual Guide and basic info --
The picture below shows the range of starters I looked at for parts interchange. Only the top row are viable candidates for parts. The lower row with Elite SB50 and 94-2001 Elite SA50 use a different armature brushes and brush holder.

Edit: 04/25/2020 - updated pic. Change: TG50 starter was 10 teeth, now shows 11 teeth. Input from harleyracer59 - thanks, much appreciated!

-- Photo comparison --

-- Building a Gyro Starter --
Below is what I'd do to repair or replace a Gyro starter:
Standard disclaimer: I am not a Gyro starter seller or rebuilder and have no contact with any of them.

Issue: Bad brushes/springs/front bearing
1) Use parts from Suzuki LT-80 starter rebuild or brush kit. This starter uses identical brushes/springs and brush housing. Also same ball bearing and oil seal for the starter shaft

Issue: Bad or no existing armature but have rest of a Gyro stater core:
1984 Gyro model NN50: Use a 1984-1985 Spree 10 tooth. Slow cranking and binding results from 11T armature in this model.
1985-85 Gyro model TG50: An 11 tooth Spree or 11 tooth 1985-87 Aero or 88-93 armature

Issue: No starter at all
1) Take your pick of 1985-87 NB50 Aero starter or 1988-93 SA50
2) Rotate the can on re-assembly by 180 degrees to reverse the CCW rotation to CW for the Gyro
3) Probably best to add the oil seal to output shaft. Only NN50 and TG50 starters had shaft oil seals.
4) NN50 only: Change the armature to a 10 tooth from an early Spree
5) Minor change: The +v tab of the Gyro starter is narrow than the replacement starter.
Replace the Flag terminal on the Harness with a ring terminal, or file to fit. I recall the file to fit method did not leave much
material left around the hole of the tab. So changing the harness to a ring terminal is a better idea.

--- Edit history
04/25/2020 - Detail starter tooth differences between 1984 NN50 and 1985-86 TG50.
Changed version: NN50 Gyro is 10T, TG50 is 11T

-- Reversing starter rotation --
As previously posted, the 1985-87 Aero/88-93 Elite SA50 starter have a counter clockwise rotation. This is reversed from the clockwise rotation of a Gyro starter.

You can rewire the starter internally to swap the +12v and ground leads. However it's easier to rotate the starter can by 180 degrees.
Take off the can, a few seconds on the grinder and put it back together.

The pic below shows the alignment tab which needs to be ground:

Starter Rebuild parts
These are the parts contained in the LT-80 starter rebuild kit I have. Some rebuild kits may omit the brush holder or other parts.
In between the kits are OEM Gyro starter mount plate, brush holder, brushes and springs.
Brush comparison Gyro vs LT-80 Brush kit

great thread Mr Mouse!!! this should help out lots of people. you just need to correct the 84, 85-86 10 tooth 11 tooth difference. everything else looks colrrect.

great thread Mr Mouse!!! this should help out lots of people. you just need to correct the 84, 85-86 10 tooth 11 tooth difference. everything else looks colrrect.

Thank you harleyracer59 for finding the 11T issue. I made changes to the thread per your input

-- Rebuild component dimensions
Builders may be able to source replaements easier/cheaper/with Name Brand Quality, rather than the aftermarket rebuild kit parts. Here's dimensions:

-- Brushes --
Brushes dimensions for the Aftermarket part were used to get the 'new' length.
Length: 6mm
Width: 7.5mm
Height: 4.5mm


-- Ball Bearing
The ball bearing is labeled as a 698Z and manufacture as NTN. NTN specs show a 698Z is a single sided shielded bearing. But upon flipping the bearing over it is double shielded. Thus the part matching what was in my starter may be listed as a 698ZZ.

698Z Bearing:
OD: 19mm
ID: 8mm Shaft
Thickness: 6mm

-- Shaft Seal --
The seal was unlabeled. Measurements:
OD: 17mm (0.670" measurement)
ID: 8mm (part destroyed, used shaft dia of 8mm)
Thickness: 5mm (0.196" measurement)

-- Supporting photos --

mousewheels wrote: ↑Sat Apr 18, 2020 7:56 pm Issue: No starter at all
1) Take your pick of 1985-87 NB50 Aero starter or 1988-93 SA50
2) Rotate the can on re-assembly by 180 degrees to reverse the CCW rotation to CW for the Gyro
3) Probably best to add the oil seal to output shaft. Only NN50 and TG50 starters had shaft oil seals.
4) NN50 only: Change the armature to a 10 tooth from an early Spree
5) Minor change: The +v tab of the Gyro starter is narrow than the replacement starter.
Replace the Flag terminal on the Harness with a ring terminal, or file to fit. I recall the file to fit method did not leave much
material left around the hole of the tab. So changing the harness to a ring terminal is a better idea.

OMG!!!

I just ordered a cheap SA50 starter for $35 since the highly messed up Gyro that I'm rebuilding needs a starter. The thing was left in the woods for who know many years on a rural lot. I almost had the starter working (the bearing was seized up tight from rust) but then a magnet came loose in the can and I couldn't get it back in right. So basically, it's trash now. I tried gluing it back but then the armature wouldn't fit in, and I butchered the magnets with a dremel trying to fix it.

If I could get those rusted internal screws to turn without destroying the plastic base, then maybe I could swap out some parts and use the new can, but I don't see the point in doing that if turning the can around on the new starter is all I have to do. I tried to undo one of of the screws and it was stripping, so I don't think that's gonna happen.

mousewheels wrote: ↑Sat Apr 25, 2020 4:33 pm -- Shaft Seal --
The seal was unlabeled. Measurements:
OD: 17mm (0.670" measurement)
ID: 8mm (part destroyed, used shaft dia of 8mm)
Thickness: 5mm (0.196" measurement)

Where does the seal go? I can't seem to find any pics of how these come apart/go together.

Maybe I need to worry about my rusted up pinion gear before I start messing with starters... it was loose in the case by the starter. Not sure why, bad bushing maybe.

Where does the seal go? I can't seem to find any pics of how these come apart/go together.

The mounting plate of the Gyro starter is machined to seat both the bearing and the oil seal. You can see the distinct steps in the plate for each component.
The oil seal is installed such that the garter spring side is towards the crankcase.

mousewheels wrote: ↑Sat Jun 06, 2020 9:06 am

Where does the seal go? I can't seem to find any pics of how these come apart/go together.

The mounting plate of the Gyro starter is machined to seat both the bearing and the oil seal. You can see the distinct steps in the plate for each component.
The oil seal is installed such that the garter spring side is towards the crankcase.

Bearing_and_Seal_b.jpg

Thank you. I guess I have nothing much to lose to try to get the rusted old screws out. Not sure I will be able to though. I am probably going to have to replace the second gear assembly and all from rust too. I got 2 of the shoes off and the third is so stuck that the mounting stud it is supposed to move on is turning with the shoe, so I can't remove the shoe. Half or more of this engine/trans needs replacing from rust. At this rate, I just need a whole donor engine/trans. I'm trying to reach someone who has one for sale that needs rebuilding (missing the starter, stator, LH crankcase cover, carb, etc) but no response yet.

Hmm, how do you get the armature out? I might have further ruined the old starter, if that's even possible given it's condition to begin with. I couldn't get the internal screws to turn for anything so i cut off the heads thinking it would give me a shaft to grab with vise grips... nope. I'll have to try to drill out the screw. I doubt that is gonna go well. But first, I can't get the armature out. The plastic ring part wont come out without the armature coming out first.

I'm guessing the shaft is stuck to the bearing from rust. I can't seem to knock it out with neither a dead blow hammer, nor a small sledgehammer. So.... short of buying a used Gyro starter to get parts from, I will have to run an SA50 starter with no seal.

3) Probably best to add the oil seal to output shaft. Only NN50 and TG50 starters had shaft oil seals.

gyro starters.jpg (48.96 KiB) Viewed 12107 times

Ok, so based on that snipped of your pics above and what said, you CAN add the seal, right? Unless cheap aftermarket motors don't have the space.

Hmm, how do you get the armature out? I might have further ruined the old starter, if that's even possible given it's condition to begin with. I couldn't get the internal screws to turn for anything so i cut off the heads thinking it would give me a shaft to grab with vise grips... nope. I'll have to try to drill out the screw.

On a typical starter the armature is just a light friction fit on the bearing id, and the bearing od is not very tight either. It's probably just the corrosion holding up disassembly.

Ok, so based on that snipped of your pics above and what said, you CAN add the seal, right? Unless cheap aftermarket motors don't have the space.

The seal fits the SA50 starter in the photo. What I do not know is that for all years SA50 starters were machined to fit a seal.

On the aftermarket side, I have bought them a few times (but its now many years in the past), and none of them were machined to fit a seal

SA-50 starter with seal added Aftermarket SA-50 starter without machining for oil seal

Interesting. The cheap SA50 starter I bought appears to have the area for the seal. There is a space between the bearing and further out lip..

mousewheels wrote: ↑Tue Jun 09, 2020 12:17 pm

Ok, so based on that snipped of your pics above and what said, you CAN add the seal, right? Unless cheap aftermarket motors don't have the space.

The seal fits the SA50 starter in the photo. What I do not know is that for all years SA50 starters were machined to fit a seal.

On the aftermarket side, I have bought them a few times (but its now many years in the past), and none of them were machined to fit a seal

SA-50 starter with seal added
OEM_SA50_Starter_with_oil_seal_installed.JPG
OEM_SA50_Starter_with_oil_seal_installed_2.JPG

Aftermarket SA-50 starter without machining for oil seal
Clone_SA50_no_seal_provision.JPG

So some of this makes sense to me but some does not. I have an sb50p and pulled the starter off and took it to a starter alternator shop and he said it was fried. Now trying to find a starter for it is difficult.

What I have gathered is if I pick up an sa50 starter, rotate the case 180 degrees then it will start to spin clockwise and I can use that, even though the mounting plate has 2 holes instead of the 3 on a SB50P?

Any help is appreciated