How to fix stripped threads / stripped bolt hole on a small engine!!! (Helicoil insert installation)

Hey everyone!
Welcome back to my channel!!!
This video shows how to step by step install new threads into a stripped hole on my Stihl chainsaw engine. I found two thread holes for the cylinder head stripped, and without a proper fix, this chainsaw would be useless.
This video shows my step by step repair of the stripped threads. I drill, tap, and then install the new helicoil thread insert.
The holes I tapped and fixed are on a Stihl engine case, however, this is the same process that would be used on any other piece of equipment with a machine thread.
Problem solved!
Link to full repair: • How to install a Meteo...
- Dave

[@JohnR9965]

100% agree. Don’t be afraid if something goes wrong trying to fix stuff. Lessons learned.

[@DavesSmallEngines]

You got it John! How else do you learn?

[@apatterson8128]

Your camera angles and resolution are amazing. Very clear. I didn't have to squint at all. Thank you, Dave.

[@DavesSmallEngines]

Wow! Thanks! I’ve had some issues sometimes getting it to focus but I am quite impressed with this camera!

[@milesbrett7002]

I have installed many heli coils over the years mainly into aluminum pumps, meters etc. When installed the thread has much more pull strength than the original as it is the same as using a larger size bolt.They are great for repairs to a wide range of applications and your use is a perfect fix on the chain saw.

[@DavesSmallEngines]

That’s awesome Miles! Good to know!

[@stellarproductions8888]

I have done this process, and watched others do it as well. It was nice to see you fix the block bolt holes, and its fun to do! Your learning pretty good there Dave. I was also happy that you didn't get the shavings down in the crank too. Good work buddy! :)

[@DavesSmallEngines]

Hey Stellar! Glad to see you back. Thanks again, it all worked out! Stay tuned for the full repair video coming soon.....

[@justingiese6544]

Keylocking inserts for the win. Drill, tap, hammer, done. Fixed some stripped holes in some edelbrock aluminum cylinder heads on my dads 390 FE that way. Never better

[@DavesSmallEngines]

That’s awesome Justin!

[@rogermcdonald1607]

Great fix it video Dave! I as a machinist have repaired my share of bad threads in aluminum, steel, cast iron, etc. You did a great job and looked like a pro. I already watched your assembling of that saw. Great job as well! 🇺🇸🇨🇦⛄ Roger

[@DavesSmallEngines]

Hey Roger - I haven’t posted that video of the 361 rebuild yet - look for it in the coming days. Thanks for the kind words!!! By the way - is there anything you would have done differently on the repair?

[@rogermcdonald1607]

@@DavesSmallEngines Absolutely not! You did a great repair my friend!👍

[@timmyturner6703]

Thanks , i have 2 threads to cut on a stihl ts400 exhaust and im just swotting up . Thanks for posting

[@georgewang4963]

Thank you for making this video and encouragement to DIY! I will try this method to fix my air compressor with a stripped bolt holes👍

[@DavesSmallEngines]

Hey George! Thanks for watching. Let me know if it worked for you!!!

[@thewheelingtinkerer2959]

Great video Dave, Very informative really like your videos with Don as well Keep it up!!

[@DavesSmallEngines]

Thanks!!!

[@chuckuu9294]

Dave good day. Excellent vid on how to correct stripped thread.

[@DavesSmallEngines]

Thanks Chuck!

[@shooter1817]

Suggestion only,Use painters tape to mask off cylinder holes,and other areas than can be compromised by filings and chips.no errors,then.always vac.and a drill guide block.Awesome video and advice on the confidence factor.screwing up is part of the knowledge process,i know from experience.And it does allow you to gain confidence to tackle projects you would never think of doing.

[@jhans3278]

Thanks Dave. Love your attitude.

[@DavesSmallEngines]

Thanks JHans!!!

[@10mmsocket32]

Recently did the same thing on a chainsaw for one bar bolt where the hole was stripped out. The inserts in my helicoil kit weren’t as big as I wanted them to be. I risked it and put two inserts inside the same hole. I had to make sure where second insert ended was adjacent to the beginning of the first one. It was important to guess how far the first insert should have been screwed in. It all worked out fine and the bolt screwed in. Btw grease works great to collect the shavings. Great video.

[@DavesSmallEngines]

Thanks 10mm, you must have had tons of bite for that bolt!!!

[@petev5545]

Hey Dave, great repair. Thanks

[@DavesSmallEngines]

Hey Pete! Thanks for watching.

[@darylkerr8058]

That's my gearhead all fixed like a new one again thanks Dave m8. Daryl B kerr from belfast north of Ireland 17:48 pm

[@DavesSmallEngines]

Hey Daryl! That is great to hear! Thanks for stopping in.

[@darylkerr8058]

You have given confidence the gearhead on my Kawasaki TJ53e is rung on head of the shaft with you saying bit of drilling little bit of tapping has give me the confidence to give it a Go thanks m8. Daryl B. Kerr from Belfast northern Ireland Thanks 😀👍

[@DavesSmallEngines]

That’s awesome Daryl! Let me know how it goes!!!

[@darylkerr8058]

Yes Dave no problem thanks

[@gregorydobson4307]

Hi Dave, little tip when I drill aluminium I always use Wd40 or similar to stop the drill clogging.

[@Bungi81]

Great Dave! That´s the way how to fix this demage 👍 Greetings from germany, Stefan

[@DavesSmallEngines]

Thanks Stefan!

[@pablo123b]

Great video thanks for taking the time to make it, nice and clear

[@DavesSmallEngines]

Hey Pablo! Thanks very much!!!

[@brianking1138]

Good job Dave. Helicoils are awesome. I have been trying to find some decent chainsaws to repair. I have only seen cheap crap so far. Husqvarna and Stihl are hard to find broken and cheap in Oregon.

[@DavesSmallEngines]

I do a lot of scouring. Maybe make a relationship with a local shop?

[@brianking1138]

@@DavesSmallEngines that's a good idea thanks

[@johnwagner8465]

Great...easy to understand video..thanks again

[@DavesSmallEngines]

Thanks John!

[@ebfromwyoming4118]

GREAT job Dave thk u sir for making the video sir stay warm in canada

[@DavesSmallEngines]

It certainly isn’t as warm as Florida!

[@TractorWrangler01]

A couple things Dave. First use a little grease on the tap. In that situation aluminum chips can get into the crankcase and into your bearings and also get inbeded into your cylinder wall and piston and foul all kinds of things up. The grease will capture the chips and you can recover them before they drop into the hole. go a little bit at a time draw the tap out put more grease on and continue ect. Second thing. when breaking off the piece at the bottom of the heli-coil use something magnetic to recover the steel piece that breaks off. That's worse than the aluminum chips. Just when you think everything is going well you may find 20 min into work with the saw that your starting to loose power or worse. The vac is a good Idea but once those chips drop through that hole there is very little hope that a shop vac will recover them. Not allowing them to get down there in the first place is the way to go.

[@DavesSmallEngines]

Great points - thanks Tractor!

[@lifewithabe312]

I agree about using the grease I’ve seen that on other helicoil installation instructions. My concern too was the little piece of the helicoil that’s needs breaking out. I have to do this on a 2stroke motorcycle,s oil drain plug and definitely don’t want to get that little piece in there, I’m having trouble understanding how I’d keep that from going in there. Also was thinking I’d apply locktite to the helicoil before screwing it in? Let it cure 24 hours before adding gear oil?

[@dujeamizic3588]

Nice video!I can't wait for next one

[@DavesSmallEngines]

Thanks Duje!

[@doglegjake6788]

thanks for sharing a awesome video !!

[@DavesSmallEngines]

Thanks Jake!!!

[@francislang5075]

good job using the Helicoil insert

[@DavesSmallEngines]

Thanks Francis!

[@robfahey1349]

I'm not automotive savvy, but I totally agree with the small engines. It's generally not that much of a loss if a piece of your equipment breaks the worst you have to lose is some time, the best you have to gain is knowledge and experience and you can always tear it down for parts is the beauty of small engines.

[@DavesSmallEngines]

That's why I love them so much. I have built several car engines, and owned even more cars. The risk is too high for me these days. This certainly has more of a hobby feel without the pressure of a huge investment, expensive parts, storage, licensing, vehicle safety checks, etc.

[@robfahey1349]

@@DavesSmallEngines exactly I feel like working on them has helped me troubleshoot and understand my car alot better even though I'm still hesitant about doing the work on my vehicle I have a good idea of the problem so I know if a mechanic is trying to rip me off or not.

[@DavesSmallEngines]

@@robfahey1349 absolutely - that knowledge will save you lots of cash... even just knowing the problem.

[@Tazzspaz]

That kit is nice because you don't have to think much about the drill bit and tap to use. But other kits may not come with a drill or a tap so make sure to read the specs on the helicoil inserts and it will tell you what to use. Also a word of caution on the tapping operation. This is where things can go from bad to worse. Go very very slow. Make sure the tap is cutting and doing the work. Don't force it. I like to pull the tap out to clean out cuttings occasionally. If the tap breaks you can be in a world of hurt because it is hardened steel and really hard to drill out!

[@pchili4]

Nice work Dave👍 pretty soon donyboy will be asking you for advice!🤔

[@DavesSmallEngines]

Nah, not even close!!!

[@ebfromwyoming4118]

FUNNY

[@numba9792]

Is it okay to use thread locker on the inserts?

[@appleztooranges]

Nice video! I get frustrated with broken bolts. My Honda 1332 is still dying during storms. Very strange. The dealer told me to leave fuel cap loose and see if that makes a difference since it’s not breathing. I’ll give this a try

[@DavesSmallEngines]

That is frustrating, not what you expect from a Honda!

[@appleztooranges]

@@DavesSmallEngines I’m making video of it soon lol.

[@DavesSmallEngines]

@@appleztooranges I don't hear the engine, nor hear it dying out?

[@appleztooranges]

@@DavesSmallEngines you’d have to watch the video I sent donyboy73. This was just a summary of what happened. It was the charcoal filter in the fuel cap. Ever heard of this? Starved my engine and died everytime. I put my Honda on its front end to clean and inspect the bottom even with a sandwich bag and a 3/4 fuel tank of gasoline and it got saturated. Thus no longer was the cap venting properly. The dealer said he’s seen this before on many Honda engines. I guess it’s a common thing if you overfill the tanks or put it on its front or transport it funky. Good to know for future. The dealer said starting around my year (2013) and newer Honda has used this charcoal gas cap as a means for filters. I will not be tipping my machine on its front moving forward kzbin.info/www/bejne/jIuQhYeXbNGIfck

[@edwintahaymontufar6899]

Can you share a link where i can purchase a kit like yours, i have problems with stripping chainsaw holes.

[@37yearsofanythingisenough39]

Dave if you know someone who has a lathe have them make you a drill guide from a round piece of steel bar stock that has a hole drilled through it lengthwise and faced square on both ends. The hole drilled through it should allow your helicoil drill to just pass through. The bar stock should be large enough in diameter that once the hole is drilled there is enough of a wall thickness left to sit on the machined surface of the item you want to repair. It now looks like a thick walled bushing. Holding this down to the machined surface will now allow you to drill your hole with a portable drill without wondering if you have the drill perpendicular to the surface. If you want you can also have one for the tap. You now have a drill/tap guide for a particular size. Engrave the size and it’s use on the side of it and store it with your remaining helicoils for the next time. If you think you will be going into mass thread repair then the drill guide should be made of tool steel, hardened, and tempered, but for 20 or 30 holes it will be fine.

[@DavesSmallEngines]

That’s a fantastic idea. I will look into that. Right tool for the right job, eh???

[@robfahey1349]

@@DavesSmallEngines I believe they sell a jig to attach to a drill to basically make it into a portable drill press this way your square. I can't remember the name of it or brand but I'm sure a Google search will reveal it.

[@robfahey1349]

@@DavesSmallEngines www.rockler.com/rockler-portable-drill-guide it's pricey but probably the best picture for an idea of what I was talking about. Cheaper alternatives are made by wolfcraft and milescraft on Amazon for $30ish US dollars not sure of your equivalent.

[@DavesSmallEngines]

@@robfahey1349 Hey Rob - I have one of those... but maybe it's different than what you are talking about. It would be square but unfortunately this engine case was not square to the surface I was working on.

[@37yearsofanythingisenough39]

@@robfahey1349 usually the holes that have stripped threads on a small engine are in small or narrow confined spaces. The drill jig you proposed would be much too large for small engine work I’m afraid. Nice of you to check for Dave however. Big Gator tools make smaller hardened drill guides that machinists have made for decades themselves, but I was hesitant to recommend them to Dave because they fit a series of hole sizes and probably would not work in the application he needs them for because even they are too big and cumbersome in a lot of circumstances in small engine repair.

[@user-bm8ww4os6e]

Hi mu name is robert i have a 100 cc 2 cycle mortor that has a stripped out head nolt.i noticed there is a hair line crackinside the crank case where the head bolt goes in thats steippedim afraid of using the helacoil thinking it could make the hairline crack even bigger and the coiil braking through inside the crank case any suggestions

[@CFProton]

If you put some grease on the tap it will contain the filings

[@DavesSmallEngines]

That’s a great tip Carl! I’ll give that a try next time.

[@powrguy1696]

I was thinking you would use a stop collar, set to the depth based on the length of the removed bolts. I would be afraid of drilling too deep, or not deep enough. It's critical to be square to the drill, too. It's also a good idea to use a drop or two of oil, and while tapping, reverse the tap direction periodically to clear chips, especially in aluminum.

[@DavesSmallEngines]

Good points. I went in a bit further than the threads to make sure that I was past the taper point in the tap. I felt little to no resistance with the tap and didn’t think I needed to use any more oil!

[@daveco1270]

I've never done this myself, but when I see other people do it they go in a full turn or so with the tap then come back out a half turn then repeat until the hole is deep enough. I've also seen people use a second tap (I think it's called a square tap) that's not tapered, so they have a flat end rather than a tapered end to the screw hole.

[@DavesSmallEngines]

Hey Dave! I'll check out what others are doing. I have seen a few people and was taught this way before and as long as there isn't too much resistance, it has always been okay. Cheers!

[@lifewithabe312]

I agree about using the grease I’ve seen that on other helicoil installation instructions. My concern too was the little piece of the helicoil that’s needs breaking out. I have to do this on a 2stroke motorcycle,s oil drain plug and definitely don’t want to get that little piece in there, I’m having trouble understanding how I’d keep that from going in there. Also was thinking I’d apply locktite to the helicoil before screwing it in? Let it cure 24 hours before adding gear oil?

[@chriscs9080]

Hmm why not just use a small rope ?

[@efrainvazquez3691]

I found them thank you

[@DavesSmallEngines]

Cheers!

[@michaelmounts1269]

Good video...I've used "time-certs" when I rebuilt a vw magnesium block. Never have used heli-certs. Any issues with torque specs etc? They are a hell of a lot cheaper than time-certs👍

[@DavesSmallEngines]

I haven’t seen any issues yet!

[@garrypalmer5014]

Hi dave, When you tap / break the little tab off, dose it break or bend down, if it breaks off how do you getitoutif the hole?

[@DavesSmallEngines]

The punch is there to break off the end. The vacuum / air compressor took care of that!

[@kttango9662]

Gonna try this on a valve cover bolt-the hole is very near the edge of the Head so i will oil and go slow👍 wish me luck😁

[@DavesSmallEngines]

Good luck!!!

[@131nfrank]

Just a good tap!!

[@DavesSmallEngines]

Tap Tap Taparoo!

[@efrainvazquez3691]

You showed the threaded inserts tried looking them up On eBay and Amazon cannot find them if you have an item number or code number that would work it always helps us out here to find these things I could’ve sworn Donnie put something like that a while back but I don’t know if I saved it but if you can find this for me and send it back to me I’ll be appreciate it thank you

[@DavesSmallEngines]

Glad you found them!

[@brandoncleland2566]

I use grease on my taps, it picks up a good amount of the chips and doubles as a lubricant that holds in place

[@DavesSmallEngines]

Great idea ! I’ve done that now a few times since. Works much better!

[@brandoncleland2566]

@@DavesSmallEngines thanks for posting man!

[@jaimepadilla9548]

Could you use blue thread lock on the coil

[@DavesSmallEngines]

You could, but it’s not needed.

[@denisboulard3206]

Would you recommend putting Loctite on the outside of the Helicoil before installing?

[@DavesSmallEngines]

I would not. Not required.

[@keithschlinger4950]

No loctite on heilcoils not even on bolts. The helicoil if installed properly as designed so the last tread of the helicoil should go down into the new taped treads and keep it from coming out. The coil is cut in a way that digs into the threads. This is the problem I have seen when people use helicoils. They don’t put the helicoil down far enough into the treads and they back out with bolt. Time-serts are the way to repair treads. Better then or just as good as OE treads.

[@budgillett9627]

Some rather lame brain observations and some questions. The questions first: you’ve mentioned this is your hobby so what is your day job? I’m curious about what the brand is of the ratchet wrench you use on your hex bits. Now the lame observations: I believe you’re right handed yet you also wear your watch on your right wrist. I told you lame observations. Also I’m from Nebraska USA and in another video you pronounced aluminum the same way we do. I’ve also noticed most Canadians pronounce process pro cess just like it’s spelled, however, we pronounce it praw cess and aluminum as you did. I cannot quite grasp the Canadian pronunciation. I’ve really been enjoying your videos. They’re so professionally constructed and your articulation is absolutely superb! God’s best for you and yours.

[@DavesSmallEngines]

Hi Bud! The ratchet is a simple Mastercraft unit sold in a kit here @ Canadian Tire (hardware store). What made you think I was right handed? I'm actually a south paw! Ah-lu-min-um. Not the British "Ah-lu-min-ium"!!!! I think a lot of pronunciations can vary depending where you are. My father is American so maybe I get some from him? Thanks for watching, and for the support! Cheers!

[@kellygavin2]

Dave do know of any links to completely strip down a Stihl ms230 Chainsaw and replace the entire Casing? My one is badly scored from a previous owner and the oil pump/line connector is so worn that the oil keeps leaking out! Basically I got ripped off when I bought it!!🙄

[@DavesSmallEngines]

Hmm. I haven’t seen one but it can’t be much different then any of the other Stihl prosumer saws. Are you trying to save it?

[@kellygavin2]

@@DavesSmallEngines Well its either save it or buy a new one! I've spent over 150 trying to repair it before I noticed the extent of the damage, so I think I might as well save it for myself. It would be morally wrong trying to sell it on to someone in the state it's in so yes, I might as well fix it and get experience in stripping down a saw and reassemble it back together. With the money ive already put into it I might as well fix it and keep it as a second saw if I buy a new one! Well in saying that, it all depends if I fix it properly so a good tutorial video would put me on the right track!

[@pamdemic6334]

Could the tapped thread be used without the coil piece.?

[@DavesSmallEngines]

It could... but wouldn’t be as strong. You’d also need a larger bolt

[@malikrameez703]

Thanks soo amazing video Dave

[@DavesSmallEngines]

Thanks for watching!

[@SurgeWorld]

Intersting!

[@DavesSmallEngines]

Thanks for watching!

[@keithschlinger4950]

Helicoils are good and the cheapest way to fix a striped threads. But if you want a really good repair check out time-sert. They aren’t cheap but you will never have to worry about it again. Use them on Ford striped spark plugs, even head bolts.

[@DavesSmallEngines]

I’ll check it out. Great info Keith!

[@edriley6739]

Can just drill and tap one size larger and use a larger screw

[@DavesSmallEngines]

Yep you could, I wanted to do it properly with the same size bolts!

[@teddahrable]

Where are the two tabs off of the heli coils?

[@DavesSmallEngines]

Hey Beaver ! Great catch. I forgot to explain that part... They ended up coming out with the vacuum.

[@dreadknot2238]

Face palm if u work on deck you need put it on milling to drill the hole you get 100% accuracy .

[@DavesSmallEngines]

Okay, I’ll look into that.

[@purebrawn5208]

According to buzz feed you can just wrap copper wire around the bolt and screw it in. I've spoken to Steve from Stephen's small engine bar and he agrees

[@DavesSmallEngines]

This..... is interesting...

[@jeffsaunders19]

you forgot the link in the description for the full repair video

[@DavesSmallEngines]

Hey Jeff! I’ve added it.

[@tranlee5622]

I don't get it. If you are taping threads then why you are using thread insert?

[@tc3603]

Great vid Dave. That's a nice saw.. have a look at sixtyfivefords new vid on a broken stud. It's awesome

[@DavesSmallEngines]

Thanks TC ! I’ll check it out. I’m almost done the edit on the 361 rebuild - I think you’ll like it!

[@tc3603]

@@DavesSmallEngines cool man. U have great luck finding good saws.

[@DavesSmallEngines]

@@tc3603 I do A LOT of hunting!!!

[@MrMatthews4040]

Best 👌 way to go is a wurth Time-sert kit 👌 expensive 👌 it does the job far better than Hele coil type fixing and is much stronger 💪 too and won't put out or rot like a Hele coil wire will Time-sert locks itself into the parent thread and forms a permanent seal aswell go check ✔ them out on KZbin.

[@chevy7134]

The insert you use are to short for that hole..The right insert size would be the 3D..

[@rickdavis2235]

Nice video. If you find yourself doing a lot of this type of work, make yourself a tapping block. It can be square or cylindrical and square and flat on both ends and should have a clearance hole for the size tap you use. You hold the block down securely to the machined surface that you are tapping and start your tap that way. It makes sure the tap is going in straight. Also, a cheap tap handle would be much easier to use and has a better feel than a ratchet and extension. There are also a slew of tapping fluids, some specifically for aluminum that can build up on a tap and could cause them to tap oversize. That's not a good thing when inserting Heli-coils.

[@DavesSmallEngines]

Thanks for the good tips Rick! I have lots to learn. Cheers!

[@rickdavis2235]

@@DavesSmallEngines You're welcome, Dave. I have a question for you. I have a Poulan P3816 that I put a new after-market carb on, gasket, new fuel filter, lines, air filter, spark plug and primer bulb and can't get the saw to start. The compression is good, the saw started and ran for about a minute or so and I haven't been able to get it started since. The saw looks like it's pretty new and just sat with old fuel in it. I turned the H and L screws in and backed them out 2 turns, again at 1 1/2 tuns and it won't fire. I also tested the coil and plug. Can you recommend anything? Also, is it a bad idea to use starting fluid to start saw initially?

[@DavesSmallEngines]

@@rickdavis2235 do you have the gasket between the carb and engine block positioned properly? Is there any pressure loss when you open the fuel tank lid?

[@RaleysSmallEngines]

Great job Dave ! Here in South Carolina (you know we have an accent) we call it .... Heee Leee Coil 😃

[@DavesSmallEngines]

Y’all call it different?

[@RaleysSmallEngines]

@@DavesSmallEngines 😆🤣