used blue loctite on cylinder screws, now can't get out

[crotchclimber]

I put a new cylinder and piston kit on a MS661C. One of the rings is binding so I need to take it back off to see what's going on. Trouble is, I used blue loctite (never doing that again) on the cylinder screws and now three of them won't come out. I tried a soldering iron and then a small torch on the head of the screw but it couldn't heat it up to the 482* melt point being in the crankcase heat sink. Any ideas on how to apply more torque to them? The two in the rear are very hard to get to. Might have to drill out the cylinder fin access holes to get a sturdier extension down it. Sheared off a Stihl T27 scrench and the Wiha plastic t-handle isn't enough.

 

[HarleyT]

Use a drill/driver with impact action.

 

[Seedling345]

You using propane or map gas? They make fine tips for map gas. My noob opinion is more heat or drilling.


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[LonestarStihl]

Heat and impact

 

[Mad Professor]

Just curious why did it lunch the P/C and is the new one OEM or Chi-Com?

Blue loctite should loosen up. IMHO If you use OEM stihl cyl bolts a bit of permatex or silicone is all you need on cyl bolts.

Make sure all the debris is out of the screw heads before you try to seat the torx.

 

[Sepia]

Take the tank and carb off and throw it in the oven at 300 for an hour.

 

[crotchclimber]

Use a drill/driver with impact action.

The question is how to use the impact driver on them. Would require a special long thin bit or drilling out fin holes for a long 1/4" bit holder.

 

[crotchclimber]

Take the tank and carb off and throw it in the oven at 300 for an hour.

It might come to that. At what temperature would the paint/powder coating get damaged?

 

[crotchclimber]

Just curious why did it lunch the P/C and is the new one OEM or Chi-Com?

Blue loctite should loosen up. IMHO If you use OEM stihl cyl bolts a bit of permatex or silicone is all you need on cyl bolts.

Make sure all the debris is out of the screw heads before you try to seat the torx.

I'm not totally sure why the p/c got scored (both on intake and exhaust sides). Probably because it never ran very well since we got it. Tons of carbon buildup on top on the piston and cylinder. I'm putting a new fuel solenoid in it to see if that helps. It helped our other mtronic saws that weren't running right. But from what I've heard some of the 661s are good and some are lemons. The replacement I'm installing is Chinese, Easysaw. This is the second p/c replacement I've done. First was a 201tc that got straight gassed a few months ago. Used a Meteor kit on that one. Ran well for a while, now has some issues I need to look into again.

 

[HarleyT]

http://www.ebay.com/itm/Wiha-74590-...092895&hash=item23761359fd:g:AdwAAOSwealY46b4

 

[crotchclimber]

http://www.ebay.com/itm/Wiha-74590-...092895&hash=item23761359fd:g:AdwAAOSwealY46b4

ordering, thanks for the link

 

[HarleyT]

Yeah, just using a tool with impact action will break it loose. Don't worry about heat.

 

[Sepia]

It might come to that. At what temperature would the paint/powder coating get damaged?

I can't tell you at what temp the paint will be affected, but it is well north of 300 - likely well north of 500! Anyway, 300 is safe for paint and rubber bits, but not for gasoline lol.

 

[cus_deluxe]

ordering, thanks for the link

I have the same one, very high quality.

 

[Robin Wood]

i get into this kinda mess myself sometimes and i just hate it
the heat trick helped me most times, hope it comes off with the impact punch
another way is to use a reverse thread puller or whatever they call it
be patience !

 

[earlthegoat2]

I always blue loctite the cylinder screws and never had a problem getting them out with the Wiha T handle. I do usually use an impact driver to remove them though.

You must have really muscled them on there. They are still M6 screws like on an 046? Right?

 

[blsnelling]

I can't tell you at what temp the paint will be affected, but it is well north of 300 - likely well north of 500! Anyway, 300 is safe for paint and rubber bits, but not for gasoline lol.

I've seen the factory finish blister at much lower temps. I wouldn't risk it.

 

[Sepia]

I've seen the factory finish blister at much lower temps. I wouldn't risk it.

Stihl Sm tells you to heat the case to 275 for bearing installation. You are saying the paint will melt if you follow Stihls' instructions? At what temperature did you notice factory paint blister?

I have stuck a few cases in the oven at 300 and never seen any ill effects other than a burnt finger once lol.

 

[xxl]

what about using a soldering iron to heat the screws?

 

[rmh3481]

Harley is only kidding you...
>>Yeah, just using a tool with impact action will break it loose. Don't worry about heat.<<

You start reefing on those bolts and you will snap the heads off. Then you will be drilling the case or paying a machine shop to get them out. Heat the bolts or the portion of the case with the threads to loosen the compound before you strip out the torx or hex heads. You can use a heat gun, a soldering iron, a small tip on a propane torch, etc.

I know you said it was blue but its acting like red.

Here is some info from Henkele that may help you.

http://henkeladhesivesna.com/blog/how-to-remove-red-threadlocker/