# Starter motor gets loose - HMSK80



## flymo (Feb 9, 2018)

I can't figure out how to keep the starter motor bolts from loosening on my 90s vintage Ariens 824. The threads in the block, admittedly, are not in perfect shape, although I did clean them up with a tap.

I've tried two types of Loctite, lock washers, and both Loctite and lock washers together. My next step, out of desperation, is to JB Weld the bolts in there, but I thought I'd see if anyone had any ideas before going to that extreme.

Thanks!


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## JLawrence08648 (Jan 15, 2017)

Monster glue? A drop of Super Glue? Toothed washers


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## jsup (Nov 19, 2017)

flymo said:


> I can't figure out how to keep the starter motor bolts from loosening on my 90s vintage Ariens 824. The threads in the block, admittedly, are not in perfect shape, although I did clean them up with a tap.
> 
> I've tried two types of Loctite, lock washers, and both Loctite and lock washers together. My next step, out of desperation, is to JB Weld the bolts in there, but I thought I'd see if anyone had any ideas before going to that extreme.
> 
> Thanks!



Helicoil. Problem solved, and a much better/stronger way to thread in. 



The bolts were probably a little loose and beat the snot out of the threads, causing this problem.


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## flymo (Feb 9, 2018)

Thanks - at this point it will probably be spring before I tackle it. Fortunately the unit starts easily, usually on the first pull. I'm thinking either helicoil, or if there is room I may glue a stud in there and then use a nylock nut.


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## vinnycom (Nov 6, 2017)

for my 30+yr old 10hp blower it was easier to just do the one pull on the rope to get it started than find my extension cord, unwind said cord, plug it into outlet and then plug it into machine.
then rewind what i just did to put the cord away.
odd that my lawn mower is harder to pull start it


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## RedOctobyr (Mar 2, 2014)

flymo said:


> I'm thinking either helicoil, or if there is room I may glue a stud in there and then use a nylock nut.


Helicoil is probably the most robust solution, but its riskier. If drilling goes wrong, if it blows through the side of a boss, etc, you might create a different/bigger problem. 

Red Loctite or JB Weld, and putting in a stud is an interesting idea. I don't know what's near it, but red Loctite requires a torch, if it ever had to be removed. 

If you went that route, maybe put in the adhesive/Loctite, thread in the stud, then snug a nut against the engine. The nut will keep the stud pulled away from the engine, and tight against the threads, as the adhesive dries. That way the stud will already be "in position", the way the stud will be pulled during use, once the starter is reinstalled. Rather than sitting one way in the loose threads, hardening, then be pulled differently once you mount the starter.


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## JLawrence08648 (Jan 15, 2017)

By using a stud you may not be able to slide the starter out, you may be able to flip it outward.


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## Kiss4aFrog (Nov 3, 2013)

I was thinking clearance with the tank above the starter but using studs you might have to pull the recoil/shroud to get the starter in and out if as mentioned above you can't angle it in there. Not that it would be that often you'd be replacing it.

.


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## Toro-8-2-4 (Dec 28, 2013)

Blue removable Loctite should work. I would suggest getting a new tube. I have had Loctite go bad on the shelf. It never fully dries. Make sure the threads on the bolt and hole are clean. Spray some break cleaner or alcohol in there to clean out any oil and blow it out with compressed air to dry it. You can even use a hair drier to help speed the curing as it is pretty cold out now.


But, if the threads in the alum block are really worn you best go with a Helicoil or similar. If you are only catching 10% of the thread or something ridiculous like that it is a problem. 

You want it removable unless you go with the stud concept. Other have well explained the down side of that approach. But it will work.
Good Luck.


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## gibbs296 (Jun 22, 2014)

Or carefully see if you could use slightly longer bolts if there are any unused threads in each bolt hole. Make sure they don't bottom out before the starter is tight. An extra washer or two could fill up the gap, if this is the case.


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## tpenfield (Feb 24, 2015)

I've had the same issue with a starter coming loose. The thread depth into the engine block is not much . . . maybe 3/8". I would imagine that the bolts come loose because of previously being over tightened and threads stripping out. JB weld would be an extreme, maybe Gorilla Glue would be better.


I think the helix coil as a thread repair is the best approach.


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## jsup (Nov 19, 2017)

3/8 isn't a lot of depth. OP, if you take the Helicoil approach, make sure you mark the drill depth with tape not to go too deep .


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## flymo (Feb 9, 2018)

Yes, I think much of the problem is that the threads had been damaged before I got the machine, and 3/8" depth is not a lot to work with. Fortunately the setup does not seem to require perfect alignment. I will see what I can cook up in the spring.


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## 132619 (Nov 20, 2018)

only one good fix, helicoil it,


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## JLawrence08648 (Jan 15, 2017)

Possibly you can rig, make, a metal bracket to hold it upright and in place attached to engine bolts.


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## Toro-8-2-4 (Dec 28, 2013)

With only 3/8 depth of thread and the condition in question I agree with Woodie. Helicoil it and be done.
When I worked in custom machinery the rule of thumb with thread depth in Aluminum is 2 x the bolt diameter. With a stainless steel helicoil you can really improve on the strength and tighten them down so much better with out worrying about stripping the alum.


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## RedOctobyr (Mar 2, 2014)

Do the Helicoil kits include bottoming taps? With only 3/8" of depth available, and being a blind hole, a normal tapered tap might only cut full threads into, say, half of that.


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## vmax29 (Oct 19, 2017)

Try a time sert. I fixed a starter that would not stay on with these inserts. The kits are a bit pricey but they work great for stripped out threads in aluminum.


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## Toro-8-2-4 (Dec 28, 2013)

RedOctobyr said:


> Do the Helicoil kits include bottoming taps? With only 3/8" of depth available, and being a blind hole, a normal tapered tap might only cut full threads into, say, half of that.



I believe they are available but don't generally come with a bottoming tap. You could always grind down a standard tap to make it a bottoming tap.


Timeserts are stronger but I am not sure you will know the difference on this application. I would not buy the kit just for this repair but if you have other projects in mind for its application it may be worth it.


Let us know how you make out.


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## flymo (Feb 9, 2018)

The kit I got came with a standard (non-bottoming) tap. I will see how it goes. The tap is marked 1/4-20 but obviously it is larger than that, as it fits the outside of the helicoil. Does anyone happen to know the size? The drill bit is 17/64. I use 1/4-20 all the time so having a full repair setup is worth the investment. Thanks.

As mentioned, unless we get a thaw it's unlikely I will get to this repair until spring, but I will keep folks posted.


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## RedOctobyr (Mar 2, 2014)

I don't know the size, but I don't think it's a standard tap size. They are often designated as "STI" taps, like 1/4-20 STI, which means it's for a Helicoil. 

So the exact tap size may be a bit of a mystery, but I think the question is somewhat academic, since you simply need a 1/4-20 STI tap. The pitch still needs to match your screw size, so even if we assumed the outside of the Helicoil happened to be 3/8", it would be a 3/8-20 tap, which wouldn't be standard. 

You can find a Helicoil catalog here: 
http://www.helicoil.in/pdf/HeliCoil Catalogue.pdf


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## flymo (Feb 9, 2018)

I did not know about the STI marking, which is what the tap I got shows. For reference, I found a bottoming tap here: https://www.threadtoolsupply.com/14-20-hss-sti-bottoming-tap.html

Thanks!


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## JLawrence08648 (Jan 15, 2017)

flymo said:


> For reference, I found a bottoming tap here: https://www.threadtoolsupply.com/14-20-hss-sti-bottoming-tap.html


Thanks. This is a great site. I'm glad you posted the link. It's both interesting and a learning experience to just peruse it.


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## Lottstodo (Feb 16, 2018)

I see you mentioned that you cleaned up the threads with a tap. I have seen many times where a tap was not quite the size its supposed to be especially on those that are low dollar sets. They are close but not perfect, and when used in a hole that has had damage it can make it worse, not saying that yours is not good quality just stating it happens.

Depending on your bolts if oem is Metric or SAE I have in the past taken a bad hole that was SAE and switch to a metric bolt that was just a little bigger and rechased the threads for that size bolt and it works well going either way .
Also a machinist friend told me that for a blind hole to use a end tap when cleaning up threads as it will size the hole clean to the bottom.

Also you mentioned JB Weld and studs, and received very good feedback on that, and as well the Helicoil.

One other option not mentioned is using JB Weld original or Pig epoxy and since both are suited to be milled, clean threads with brake clean flush it a few times, and paste the threads with the weld compound using tooth pick etc. but not filling the entire cavity. let it set the time and temp required per the instructions, (very important!!) and use the exact drill# for the tap required clean up the center (I have done this many times just by hand / no drill motor) and using a known good quality tap chase the threads, very slowly and backing it up every 1/4 to 1/2 turn to clean the cutter so it does not gall the threads. 

This had worked more times that I can remember and saved a lot of equipment.


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## cranman (Jan 23, 2016)

I'm going to keep that tip in my mental toolbox, Lotstodo!


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## cpchriste (Jan 19, 2014)

I've re-drilled and re-tapped these to 5/16 thread many times without problems. You then may have to slightly open the starter through holes too.
The above stated cautions about hole depth and tap incomplete threads apply. Trim bolt length as needed to get maximum thread engagement.


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## HCBPH (Mar 8, 2011)

Here's the obvious question which unless I missed it has not been answered. When the bolts are put in, do they tighten properly and hold the starter then loosen later or not?

If they tighten and you want to KISS it, here's a simple solution. Take a look at how the exhaust bolts are locked on a 10 HP Tecumseh (probably on the 8 also). A simple metal strip that goes between the bolts, when they are tightened then the corners are bent up to hold the bolts from turning. Another would be to drill small holes through the heads of the bolts and safety wire them.

If the holes are damaged, there's a helicoil insert or something I've used which is a version of JB Weld for high temp areas. I used it on an engine where the holes for the exhaust were messed up, opened it up and JB Welded a helicoil in there. Don't have much time on the engine but so far it's looking good.


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## HCBPH (Mar 8, 2011)

Here's a picture of what I was referring to


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## Toro-8-2-4 (Dec 28, 2013)

flymo said:


> I did not know about the STI marking, which is what the tap I got shows. For reference, I found a bottoming tap here: https://www.threadtoolsupply.com/14-20-hss-sti-bottoming-tap.html
> 
> Thanks!



Yes the STI means the tap it is for a Helicoil application.


Helicoils and similar inserts are usually "Free Running" inserts. This means the fastener can easily be run in and out many times.
You can also get a "Screw Locking" Helicoil which creates an interference with the fastener and prevents backing out. They are not common but it is an option that you can get on line or at an industrial supply. I doubt any auto parts or hardware stores would have them.



I don't think you need it if you have a properly sized and good condition Grade 5 or higher 1/4-20.


But, if you really want to make sure it will not back out, it is an option.


Years ago I remember using them on machines with high vibration. They have changed the design slightly as I recalled them. They were a reddish color so you don't confuse them with a free running style insert because they look almost identical.



Read about them here.


https://www.thorintl.com/HeliCoil-Screw-Thread-Inserts-Emhart-Bollhoff.shtml


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## flymo (Feb 9, 2018)

HCBPH said:


> Here's the obvious question which unless I missed it has not been answered. When the bolts are put in, do they tighten properly and hold the starter then loosen later or not?


Yes, the bolts tighten up fine, and loosen after only a short period of running. I am not trying to make the bolts super-tight, for obvious reasons. I did think about some kind of mechanical lock, as you describe.

To answer a previous question, the tap set I use is made by Kodiak Cutting Tools. It is American-made, and certainly appears to be of very good quality, but I have no way of checking to make sure the dimensions are perfect.

Everyone has given me great suggestions. My plan is to wait for warmer weather, then try the helicoil, possibly with a bottoming tap if needed. The backup plan would be to drill and tap to 5/16-18.


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## flymo (Feb 9, 2018)

Just to close this out, I ended up going with the helicoil. I didn't need a bottoming tap because the helicoil insert only engages the top 1/4" of the hole anyway, so the standard tap was fine. So far, with a couple of starts and about 10 minutes of runtime (no actual snowblowing happening this time of year) it seems to be holding.

It sure would have been nice if Tecumseh had made those bolt holes a little deeper - a 1/4" bore going only 3/8" into aluminum is almost certain to cause problems.

Thanks again for the help!


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## BlowerMods1 (Jan 11, 2020)

Bought a new blower this year as a parts machine. It was marked down more than half so I jumped on it. The new blower has an electric starter. Not what I ordered but I'll take it. My last machine had a electric start but it died right after the warranty ran out. Didn't replace it. The new blower starts so easy that I don't even use it. I will be keeping an eye on it though. Tip: with electric starters you want to make sure you use the correct extension cord. 12 to 14 gauge. 16 gauge is too small and will fry it. Learned that the hard way.
.


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