Stihl 084 plug threads gone.

[tkemble]

I have a stihl 084 that has been an on going project for about a year. When I got the saw off of ebay the piston and cylinder where shot. The seller claimed he didn't know. So I replaced them in June. NO problem doing that. The saw fired up after the second pull with the new cylinder set. So After doing that I went and talked to the local stihl mechanic. He said for me to replace the oil seals also. So I ordered them and waited for them to come in. The dealer lost me order and it took six weeks for them to arrive. That wasn't a problem because my wife had or first child during that time. A baby boy.

So anyway I got the oil seals and broke the saw down. MY intial problem was that I could get the clutch off. I didn't have the 21mm deep well socket so I took the saw to the new stihl dealer. The other dealer's franchise got yanked. I asked them to remove the clutch and pull and replace the oil seals. I took the saw in on 9/21. They called me back a week later saying they could get the clutch to move. I picked it up a little upset and just placed it on my work bench. There it sat tell this afternoon when I went to try and remove the clutch myself. I went to remove the spark plug and it pulled strait out. The plug will not seal. The threads are flat on top. What are my options. The dealer has the saw know, but they say we have to talk to the mechanic. How is that possible. The piston and cylinder have less than 10 minutes on them.

Travis

 

[jokers]

Keep in mind Travis that this is an armchair assessment, but it sounds pretty likely that the last shop buggered the threads. Another Stihl master technician strikes! LOL.

If you are telling us the whole story I recommend going back to that shop and demanding that they make things right, free of charge. Start with being reasonable and appealing to their better judgement but dig in your heels and demand satisfaction in whatever way that seems appropriate if they don`t take care of you. But you already thought of this, didn`t you.

Russ

 

[cbfarmall]

If you end up having to fix it yourself, here's a good and cheap solution. JC Whitney sells spark plug repair kits. The 14mm kit comes with a tap and 4 plug bushings of different lengths. My 038 had goofed up threads and my friend lent me a plug tap to use and also one of these kits in case the tap didn't work. The bushings are solid, not spirals like a helicoil. I looked up the cost and it is around $12.

Of course you still have the clutch to remove. Find a 1" impact wrench and hammer away. Kidding, don't do this. I will state, however, that a 1" air impact will hit the nut so hard that it will probably spin off without budging the crank. Probably break the nut, too.

Good luck, Chris B.

 

[cbfarmall]

tkemble,

You're not too far from me. A couple hours anyway. If you're headed in the direction of Chicago anytime soon, you can swing on by and I'll help you fix that 084. Plug threads, clutch, crank seals and all. Get the flywheel off yet?

Chris B.

 

[tkemble]

Chris,

I have the flywheel off. The 084 uses the same puller as the 056's. I stoped the piston with a piece of rope, because the piston stop listed for the 084 stihl doesn't make anymore. I think the stihl dealer used the smaller stop, thus my problem. I may have to take you up on your offer. Where in the "region" are you located.

Travis

 

[Mange]

Times like this I put in "helicoil". New threads inserted, good as new. Is this the same thing?
Have one 254xpg with thease almost everywere.
The man I got it from had broken everything he tinkerd with.

 

[cbfarmall]

tkemble,

I live in Lake Co., sourthern part, right near the intersection of route 2 and route 41. It's easy to find on your map.

Mange,

Helicoils look like springs you thread in the hole. The bushings I'm talking about are solid--tapped inside for the plug threads and threads outside to match the tap tool.

I have Helicoil kits for the 5mm and 6mm screws that are common on Stihls. Problem with helicoils is that you usually can't take the bolt out more than a couple times before the coil comes out with it. Not acceptable when dealing with spark plugs.

Chris B.

 

[WoodTick007]

Heli-Arc

Why not heli-arc the thread area and re-tap new threads? The top of the cylinder is not plated and a good wleder can weld up the old threads in just a few minutes.

 

[Mange]

Cbfarmall.
Thanks for the info, will keep that in mind.

Mange

 

[tkemble]

Well I talked to the stihl dealer today and their mechanic didn't have time to look at the saw. I just picked it up and walked out. One of the sales guys did tell me that stihl doesn't make the piston stop for the 084 anymore. I hadn't told him that piece of information. That tells me that they did use the smaller stop and ruin the threads. I am just in shock because not a single person their acts like they did anything wrong.

Thanks for the help

Travis

 

[cbfarmall]

Well, my offer still stands.

Chris B.

 

[Jacob J.]

Travis- there is a heli-coil repair available for your 084, in 14mm, I have them here. If you want, you could have Chris repair your threads or just send me the cylinder and I'll fix it free of charge.

 

[tkemble]

Jacob J.

I appreciate the offer. I am going to meet up with Chris and work on it.

Travis

 

[bwalker]

If you are going to fix it, fixit right. Use a time sert. Much better and stronger than a helicoil.
http://www.timesert.com/

 

[Mange]

I have seen this sometime, can't remember where, but they were in aluminium. I take thease are not.
Looks impressive, if they ship overseas, I will get them.

 

[cbfarmall]

The thread repair kit I have is nearly identical to what Ben just posted. I certainly would not choose to use helicoils in a situation like this.


Chris B.

 

[Crofter]

For a permanent repair go with the solid insert rather than the helicoil. Welding is very iffy. Hard to weld in a hole without filling it entirely. Porosity from dirt in threads a problem. Still have to machine for face for plug seating.

Frank

 

[tkemble]

Saw is fixed and running

I took a road trip this morning and met up with cbfarmall. He quickly tapped out the spark plug hole and loctited a insert in the hole. We removed the cylinder and cleaned it and the piston.

He then pulled and replaced the oil seals. I couldn't figure out how to the pull the oil seals. Chris pop those things out so fast I felt silly. I now know how to remove oil seals.

We put the saw together and it runs great. Still have to adjust the carb a little.

I want to publicly thank Chris for his help. He is a great guy and I learned alot from him. He has a really impressive selection of stihls also

Travis

 

[jimbo1490]

Don't weld it! I have seen cylinders and heads emerge from welding quite warped! With bigger stuff (cars, bikes, boats, etc.) this is not necessarily a huge problem since you can re-true the head or cylinder by boring or planing. You don't have that option here because of the cylinder coating.
Thread repair inserts are quite reliable, really; probably better than the threads in aluminum, which are notoriously easy to strip out. After insertion, the stainless steel wire becomes the load bearing surface, not the aluminum. Many engines with aluminum heads come with inserts from the factory since they get less comebacks that way.
I'm suprised that the dealer's mechanic did not at least attempt this sort of repair. Had he done so, you probably would never even have known anything went wrong.

Jimbo