# Tecumseh starter motor questions



## dualTrace (Dec 6, 2015)

Hi all, I have a starter motor from a tecumseh HMSK105 engine. 
The engine would not start with the starter, starts fine with the pull cord, so I removed it. The starter runs but doesn't seem to turn the engine over. Running it on the bench the small gear on the starter which engages the flywheel moves into the extended position when the button is pushed but does not remain extended as the motor spins. Is it supposed to remain extended as long as the motor is spinning? I haven't taken it apart yet but I can't smell anything burnt and it seems to spin ok. I've no experience with these starters.

charlie


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## UNDERTAKER (Dec 30, 2013)

the started gear flys out to the flywheel when the switch is engaged. post a vid of this problem.


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## motorhead64 (Dec 15, 2013)

Hi dualTrace
The starter should remain extended during cranking, and retract when the switch is released. MH


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## bad69cat (Nov 30, 2015)

It should stay out as long as you are on the button. You might pull it out and take a look at the gear and make sure things are in good shape. It might have a bad brush or contact point also.... look on youtube for starter videos. Lots of good info on there....


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## dualTrace (Dec 6, 2015)

Thanks for the quick replies guys. Ok the gear extends when the button is pushed but retracts almost right away even if the button is still pushed. If I release the button and push it again the same thing happens. I took the gear off and everything looks good with no wear that I can see. I lubed everything with some light oil and reassembled with no success, the same behavior. Is the rotational speed of the starter tied into this extension and retraction action? Thinking maybe the thing is not rotating fast enough.
charlie


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## UNDERTAKER (Dec 30, 2013)

then there is something wrong going on there. just tossing this out there. get a new gear. I am sure some one here has more ideas on that 1.k:k:k:k:k:


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## bwright1818 (Dec 2, 2014)

The gear needs resistance from a load (the cranking of the flywheel) so STAY out. It will not stay out during a bench test. That's normal. Now, what would not be normal is if you held the gear with LARGE pair of water pump pliers and it stayed still while the starter turned. MAKE SURE YOU UNDERSTAND THAT EVERYTHING HAS TO BE HELD VERY TIGHT FOR THIS TEST. THE BEST WAY TO DO IT WOULD BE TO PUT IT BACK ON THE ENGINE AND LOCK THE FLYWHEEL SOMEHOW. DON'T HURT YOURSELF. The "Bendix," as some refer to it, can go bad, and slip under a load. You might just need to replace the gear assembly anyway; but no-load, they are NOT going to stay out while turning.


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## dualTrace (Dec 6, 2015)

bwright1818 .... Thanks for this information, just what I needed to know. I'll stick it back on the machine and see what happens. Maybe with a little cleaning and lube the thing will work. Gonna have a closer look at the ring gear on the flywheel too.


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## YSHSfan (Jun 25, 2014)

bwright1818 said:


> The gear needs resistance from a load (the cranking of the flywheel) so STAY out. It will not stay out during a bench test. That's normal. Now, what would not be normal is if you held the gear with LARGE pair of water pump pliers and it stayed still while the starter turned. MAKE SURE YOU UNDERSTAND THAT EVERYTHING HAS TO BE HELD VERY TIGHT FOR THIS TEST. THE BEST WAY TO DO IT WOULD BE TO PUT IT BACK ON THE ENGINE AND LOCK THE FLYWHEEL SOMEHOW. DON'T HURT YOURSELF. The "Bendix," as some refer to it, can go bad, and slip under a load. You might just need to replace the gear assembly anyway; but no-load, they are NOT going to stay out while turning.


I've never dealt with a small engine starter, but on an automotive starter when you bench test it, the gear of the bendix comes out and stays out during testing (unless my memory is failing on me :facepalm_zpsdj194qh), the stripped gear scenario sounds possible but it should be making funny noises I would think. If no visibily, He could always remove the pull cord assy and shrhouding and take a look at what is happening.

Is it possible that the engine does not have a flywheel with ring gear?


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## dualTrace (Dec 6, 2015)

hsblowersfan.... the engine does have a gear on the flywheel, the starter worked before. My 85 year old uncle, who lives across the street from me, owned the machine from new and gave it to me last week. He bought a new Honda, $4000.00, man is that thing quiet when running. I might just remove the recoil assembly and have a look, it's not retracting the cord all the way so it'll give me a chance to check that out too. So now we have 1 for and 2 against the gear staying extended during testing on the bench. Anyone else care to weigh in?
charlie


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## ELaw (Feb 4, 2015)

I'm with bwright1818... I don't think the gear will stay out unless there's a load put on it. When the starter is first energized, the gear's inertia provides the "load" and it moves out to contact the ring gear. But if the load is not maintained (by having the starter gear drive the engine) the spring in the mechanism will return the gear to its resting position. That doesn't happen on (modern) car starters because they have a solenoid that moves the gear to the engagement position and holds it there.

I got a snowblower last spring that had seemingly the same problem you're having. The starter seemed to function just fine, but it didn't drive the engine. I looked everything over and the starter gear was extending properly, and there was a ring gear on the flywheel, but the starter gear didn't make contact with the ring gear. It was as if the ring gear was too small a diameter.

I tried bolting on another starter from a similar engine and the problem went away. So in my case, I concluded the starter was not the right one for the engine. It was obvious from a few other things that the engine was a "mix-and-match special" and I think the person who built it mixed-and-matched the wrong starter.


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## bwright1818 (Dec 2, 2014)

ELaw said:


> I'm with bwright1818... I don't think the gear will stay out unless there's a load put on it. When the starter is first energized, the gear's inertia provides the "load" and it moves out to contact the ring gear. But if the load is not maintained (by having the starter gear drive the engine) the spring in the mechanism will return the gear to its resting position. That doesn't happen on (modern) car starters because they have a solenoid that moves the gear to the engagement position and holds it there.
> 
> I got a snowblower last spring that had seemingly the same problem you're having. The starter seemed to function just fine, but it didn't drive the engine. I looked everything over and the starter gear was extending properly, and there was a ring gear on the flywheel, but the starter gear didn't make contact with the ring gear. It was as if the ring gear was too small a diameter.
> 
> I tried bolting on another starter from a similar engine and the problem went away. So in my case, I concluded the starter was not the right one for the engine. It was obvious from a few other things that the engine was a "mix-and-match special" and I think the person who built it mixed-and-matched the wrong starter.


That's exactly right and better explained than I did. These Tecumseh starters are very similar to outboard motor starters, which I am very familiar with.


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## bad69cat (Nov 30, 2015)

Correct as far as my experience goes - the load needs to be maintained while cranking. If it drops back you either have 1.) bad engagement with the flywheel gear
2.) Not enough inertia to mate 3.) bad teeth 4) bad current in the starter itself - which can be a lot of things, like a brush tata is not contacting, or a bad winding. You can usually see if the brushes or windings are burned up or badly worn.

A word of caution that the starter can be a bear to put back together if you remove the brush assembly or the stator! You have to have a way to hold al the brushes back while slipping the things back together......assuming it's a rebuildable one. Some are just replace only in newer machines


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## dualTrace (Dec 6, 2015)

Hey guys... I put the starter back on the machine and have the same problem, however, if I pull the cord just a bit and try again it works ok. I'm guessing the teeth on the flywheel are probably bad. Winter is here now so I'll live with it until the spring and then have a look before I bed the machine down for the summer. Thanks for all the help, really appreciated.


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## bwright1818 (Dec 2, 2014)

Does the starter bind and not turn, or does the starter just spin freely and the engine doesn't turn? If it spins freely, does the drive gear engage the flywheel but not turn and only the starter shaft itself, spins? Tell us this and we can go from there. One way or another, this shouldn't be too bad to solve....


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## dualTrace (Dec 6, 2015)

bwright1818.... The starter spins freely but the engine doesn't turn. It's possible that the starter shaft is turning and not the drive gear but I can't see that when installed unless I remove the recoil starter to open up a view. The drive gear spins no problem when I bench tested it but maybe not under load. When I pull out the cord a little and release it the starter motor works sometimes and starts the engine. That's what got me thinking maybe some teeth on the flywheel are bad. Tangled up with Christmas here now so won't really have any spare time to go at it again for a while. Nice to have some more things to look for and I'll get back here when I get a chance to have a further look. Thanks for your assistance.


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## Shryp (Jan 1, 2011)

Those Tecumseh starters can have other issues too. The top bolts are normally shoulder bolts instead of threaded all the way. Over time they wear and the starter fits loose in there. This allows the starter to push away from the engine block. The more slop it has the worse it gets. Also, with all the pushing from the slop it starts to bend the tabs down and then the starter sits further out. Eventually it will push so far out the gears won't meet.

You could try removing the fuel tank and switching to normal bolts to get a tighter fit if it feels loose. You might need some washers too if the spades on the starter are spreading apart or breaking.


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## Bolens93 (Nov 24, 2015)

This is not a starter motor question but didn't think it warranted a new thread. I now know I have 84watts but on the sticker "This engine has provisions...." what does this symbol mean that follows "84"


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## YSHSfan (Jun 25, 2014)

It has provisions means it has a flywheel with a ring gear already installed, all you need is the starter installed.


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## Bolens93 (Nov 24, 2015)

hsblowersfan said:


> It has provisions means it has a flywheel with a ring gear already installed, all you need is the starter installed.


yes yes that I know, but if you look at the bottom right corner of the sticker in the pic (magnify) what does the circle arrow that follows 84 mean? It doesn't matter much to me but was curious. At first glance I thought rotation but rotation is clockwise but the symbol is counterclockwise


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## Grunt (Nov 11, 2013)

Just a guess. Looking at the rear of the motor, pulling the recoil turns the engine clockwise. If a electric starter WAS installed, it would turn counter clockwise to make the engine spin clockwise. :smiley-confused009:


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## bwright1818 (Dec 2, 2014)

Yeah, you should take the recoil housing off and see what's going on. If the engine is NOT turning and the drive gear is not turning but the starter shaft itself IS turning, you'd just need a new gear assembly, often called the "Bendix.." They have a little clutch deal in them that can fail. You don't have to disassemble the starter to remove the retaining nut. Just use a small impact wrench and it will spin right off.


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