Stihl 029 Super piston stuck in cylinder, cant get it to release

[Cantdog]

Penetrating oil isn't going to do anything. This piston is basically brazed in place. The piston has gotten hot and the aluminum has melted fusing it to the cylinder wall

I agree...that puppy is way beyond penertrating oil....the P&C are both junk....I also agree with the earlier post about cutting the top off the cyl....sawzall, portaband or even a regular wood band saw will cut right through that cyl, and then perhaps boring a series of holes in the piston crown with a hand drill to relieve stress....until you can tap the wristpin or what's left of whole piston out of the bore. Stuff plenty of rags around the conrod and do it laying on it's side to keep debris from getting onto the crankcase....though, from the pics that ship may have already sailed!! LOL!!! Good luck!! In my world that would be a parts saw....just sayin'...

 

[DSS]

thanks for the offer man, we will see what happens with this saw. After getting it all torn down and looking at it closely it looks like im going to need a flywheel (two fins broke off it, not my fault) a new cylinder and piston (not my fault, froze up when i got it), a new tank vent (old with age) and it couldnt hurt to get a new bar stud since i totally chewed it up trying to unscrew it from the crankcase. Honestly, without a bench vice I dont see how yall do those things.

Im guessing to screw one in though, you just put the bar nut on the stud and screw it in with an impact wrench or something?

Also, at this point im going to have to seriously think about whether its a better idea to spend $150 to rebuild it or just part it out and cut my losses.

To put the stud back in, lock both bar nuts together on it and use a wrench, not an impact.

 

[Stihlofadeal64]

You can also get a simple "stud remover" from your local auto parts store if you want it done easily. I bought mine from Stihl and never looked back. It is a "socket-like" tool with detention rollers inside that grip the stud so you can remove it with a ratchet.

I just got the new kit (MS390) from Bailey's and will probably run test it Monday. I have the muffler modded and will tweak the carb so it will run well. I am actually impressed with some of the quality I have seen in this kit. It surpasses some of the aftermarket stuff I've seen. The unassembled kit is available through E bay as well as their site for a cheaper price. Give it some thought. :msp_thumbup:

 

[jellero]

Penetrating oil isn't going to do anything. This piston is basically brazed in place. The piston has gotten hot and the aluminum has melted fusing it to the cylinder wall



heli-arc??? Really???? Please explain this technique



You lack of knowledge of modern chainsaw construction is glaring.

i thought of this today and if you have stainless steel and aluminum together sitting around for years it would just braze/weld itself together. i have a brake adjuster in my '61 harley that did just that, a stainless shaft through the aluminum brake housing, now one piece.

 

[zogger]

thanks for the offer man, we will see what happens with this saw. After getting it all torn down and looking at it closely it looks like im going to need a flywheel (two fins broke off it, not my fault) a new cylinder and piston (not my fault, froze up when i got it), a new tank vent (old with age) and it couldnt hurt to get a new bar stud since i totally chewed it up trying to unscrew it from the crankcase. Honestly, without a bench vice I dont see how yall do those things.

Im guessing to screw one in though, you just put the bar nut on the stud and screw it in with an impact wrench or something?

Also, at this point im going to have to seriously think about whether its a better idea to spend $150 to rebuild it or just part it out and cut my losses.

Part it out. Junk. Million better used saws to work on out there, requiring much less parts and labor. If it was some super rare exotic saw in that condition, sure, try to fix it, but not that saw.

 

[Chris J.]

Give it an overnight soak in penetrating oil and beat the piss out of it. Apply heat if neccessary.

I've used a little Kroil & natural sunshine to free up stuck pistons, a heat gun or a handheld hairdrier will work, but I had two P&Cs on one saw, a Disston DA-211, that were so melted they absolutely wouldn't break free.

 

[DSS]

i thought of this today and if you have stainless steel and aluminum together sitting around for years it would just braze/weld itself together. i have a brake adjuster in my '61 harley that did just that, a stainless shaft through the aluminum brake housing, now one piece.

Which part of that saw is supposed to be stainless?

 

[SkippyKtm]

Bailey's has complete aftermarket 390 engines that seem to be a good alternative to going oem and for less money.

this would be the best solution:msp_thumbsup:
finaly was able to run one last monday. pretty stout even compared to a stock 390. so far.

You can also get a simple "stud remover" from your local auto parts store if you want it done easily. I bought mine from Stihl and never looked back. It is a "socket-like" tool with detention rollers inside that grip the stud so you can remove it with a ratchet.

I just got the new kit (MS390) from Bailey's and will probably run test it Monday. I have the muffler modded and will tweak the carb so it will run well. I am actually impressed with some of the quality I have seen in this kit. It surpasses some of the aftermarket stuff I've seen. The unassembled kit is available through E bay as well as their site for a cheaper price. Give it some thought. :msp_thumbup:

Let us know how those 390 kits work out.
In my experience, I've had the worst darn luck with AM cylinders and the BB kits. I've tried 2 kits and they both weren't worth a darn. One was a 066 BB kit, and the other was a Dolmar/Makita DCS6400 84cc BB kit. If I want to save a dollar or two, I prefer to go with used oem cylinders and a decent quality AM piston ...

 

[Saw Dr.]

You have to remove the entire engine from the case, you can't just pull the cylinder with it still installed in the case and get it back together properly. The ignition, flywheel, clutch assembly, etc all have to be removed.

You do have to remove the flywheel and clutch. You most certainly do not need to remove the pan. I have done dozens of rebuilds on 1127 series saws all with the pan in place. It takes a little more time to clean the old dirko off the mating surface, but it can be done fairly easily.

 

[jellero]

Which part of that saw is supposed to be stainless?

"if"
frequently engines have stainless sleeves in cylinders.

 

[Reyn]

by disassembling this saw totally dumb like a noob would, do you mean that i should have pulled the clutch and flywheel so i can get the crankcase out of the clamshell before breaking the cylinder off the crankcase?

If so thats what im going to attempt to do next. After i re-read the service manual again, just skimmed it quick the first time. Im working on the 029 super in the garage and have a completely tore down STI 1911 on the coffee table next to me. My heads spinning.

STI 1911......:msp_wub:

 

[SkippyKtm]

You do have to remove the flywheel and clutch. You most certainly do not need to remove the pan. I have done dozens of rebuilds on 1127 series saws all with the pan in place. It takes a little more time to clean the old dirko off the mating surface, but it can be done fairly easily.

Yep, I've done quite a few myself...
I suppose not removing the pan would save some time not having to remove the pita stud that anchors it to the case (its not that bad once you've done a few). I just got used to pulling the entire assembly from the case, pan and all, its easier for me to clean everything up that way. Thanks for the tip though.

 

[sefh3]

I'm late to the 1127 party again. In my signature line there are 2 threads on how to tear this saw down and reassemble it. If you keep the saw, read the threads. If you don't want the saw, PM me. I'm looking for something for an 039 longblock from Baileys.

 

[hkusp9]

STI 1911......:msp_wub:

Yeah apparently its one of the few mechanical contraptions that i dont completely destroy as soon as i set hands on it, unlike these darn saws...

Old photo, but it still looks the same.

Also, ive decided that after i complete some other projects im going to drop a whole new baileys 390 engine in it, flywheel, rear bar stud, carb rebuild kit, and i need to find a new flywheel key.

.... Or let sefh have at it.

 

[bplust]

Let us know how those 390 kits work out.
In my experience, I've had the worst darn luck with AM cylinders and the BB kits. I've tried 2 kits and they both weren't worth a darn. One was a 066 BB kit, and the other was a Dolmar/Makita DCS6400 84cc BB kit. If I want to save a dollar or two, I prefer to go with used oem cylinders and a decent quality AM piston ...

Really? As your preference is used OEM, would you buy eBay/internet used within reason, or only locally (so inspectable before purchase)?

I didn't realize that OEM was so superior, and I really only run McCullochs that never had anything AM made, so I'm curious.

 

[SkippyKtm]

Really? As your preference is used OEM, would you buy eBay/internet used within reason, or only locally (so inspectable before purchase)?

I didn't realize that OEM was so superior, and I really only run McCullochs that never had anything AM made, so I'm curious.

Yes, I have bought from reputable ebay sellers or have swapped parts with friends, (that's the best way imo..). I'd much rather use good used oem cylinders, the AM stuff is inconsistent quality wise. Cylinders are hard (for me anyway!) to judge overall quality and to judge the hardness of their so called nikasil. I've had the coating on a NWP brand kit for a dolmar big bore 84mm (supposedly nikasil anyway) wear away with just aluminum oxide sandpaper(aluminum oxide is softer than silicon carbide) and elbow grease; it had a minor amount of transfer and it should have been an easy cleaning. I've never been able to inadvertently sand through the coating on an oem cylinder, unless the cylinder was trashed to start with.
I spend a lot of time inspecting AM pistons too and have found all kinds of issues with those as well, but pistons are easier to inspect (for me anyways). You've got to check for loose ring locating pins, excessive wrist pin slop(the wrist pin should fit snug and not rotate), improperly ground circlip grooves(usually too deep), excessive slop between the bosses that hold the wrist pin, etc. I probably forgot a few things...
Meteor does make a nice consistent quality piston, but I still give 'em the once over.

 

[thomas1]

"if"
frequently engines have stainless sleeves in cylinders.

Really? Can you give some examples?

 

[DSS]

Really? Can you give some examples?

Well duh. 029 super. Try to keep up.

Sheesh.

 

[Mastermind]

Well duh. 029 super. Try to keep up.

Sheesh.

Tom is "kinda" tarded ya know. :bang:

 

[thomas1]

Tom is "kinda" tarded ya know. :bang:

Again with the kinda, quit being wishy washy.