Stihl ms310 which case bolt? And do I need primer

[82cabby]

Hi gang
I am replacing the cylinder on my ms310. The swap mostly went fine but there is one big problem: the bolts that hold the pan to the cylinder loosen up quickly when I start running it. Two reasons for this I think: I realized too late that I forgot the loctite. And I used replacement bolts instead of the stock. Soooo here are my questions:
do I need to use loctite primer for loctite 243? The website says it works on inactive metals without a primer but the box says use primer.
Second, can I switch back to the stock bolts even though the treads are different pitch? If you look in the picture you can see that the bolts have different thread pitches. The holes in the cylinder were not threaded so when I put in the replacement bolts they cut their own threads. Obviously I should have used the original ones first but I read some where that you should use new bolts when swapping the cylinder and these were the ones that were described as replacements when I ordered the parts.

any help would be appreciated!

 

[dmb2613]

use the original ones and use loctite I use the red cause it will not get loose Clean all the grease and oil off the bolts and the holes

 

[HarleyT]

Hi gang
I am replacing the cylinder on my ms310. The swap mostly went fine but there is one big problem: the bolts that hold the pan to the cylinder loosen up quickly when I start running it. Two reasons for this I think: I realized too late that I forgot the loctite. And I used replacement bolts instead of the stock. Soooo here are my questions:
do I need to use loctite primer for loctite 243? The website says it works on inactive metals without a primer but the box says use primer.
Second, can I switch back to the stock bolts even though the treads are different pitch? If you look in the picture you can see that the bolts have different thread pitches. The holes in the cylinder were not threaded so when I put in the replacement bolts they cut their own threads. Obviously I should have used the original ones first but I read some where that you should use new bolts when swapping the cylinder and these were the ones that were described as replacements when I ordered the parts.View attachment 918176

any help would be appreciated!

That one on the bottom is what they sent you to use?

 

[82cabby]

Yes it is. I put a set of dial calipers on it and it’s about.02 narrower

 

[67L36Driver]

Go to your hardware store and get socket head cap screws proper length plus flat washers.

Turn ‘em in tight!!

Those slotted head machines screws are crap.

Clean bolts & tapped holes with brake clean and use blue Locktite.

 

[a. palmer jr.]

Maybe I'm missing something but I always just re-use the bolts that came out of the engine and have never used thread locker on any of the 290-390 engines and have never had a problem with bolts loosening up. The cylinders I buy are always threaded though..My 390 conversion is several years old now and does just fine...

 

[HarleyT]

The only danger I see now is that the use of the aftermarket screws removed enough material, to make it a problem to re-use then the OEM screws.. If they were the same pitch, I would feel a lot better about it.

 

[82cabby]

The only danger I see now is that the use of the aftermarket screws removed enough material, to make it a problem to re-use then the OEM screws.. If they were the same pitch, I would feel a lot better about it.

That was exactly my concern. But, figuring I didn’t have a lot of choice I cleaned everything with carb cleaner, used a boatload of loctite and reused the OEM bolts. They seemed to bite just fine and tightened right down. Time will tell if they hold.

 

[a. palmer jr.]

Not sure I'd ever use red Loctite on anything that I'd ever want to take apart sometime. I've used it before on bolts and it actually destroys the threads when you try to remove them.

 

[HarleyT]

Is a "boatload" the same as a "buttload"?

 

[Canyon Angler]

Not sure I'd ever use red Loctite on anything that I'd ever want to take apart sometime. I've used it before on bolts and it actually destroys the threads when you try to remove them.

It's used on rifle scope mounts. Heat to remove. Never heard of it tearing threads out of gun receivers, that would be some strong (like at least 70ksi) Loctite! I guess maybe on pot metal or whatever...though I believe Loctite says that unless both parts can rust, all bets are off.

 

[a. palmer jr.]

It's used on rifle scope mounts. Heat to remove. Never heard of it tearing threads out of gun receivers, that would be some strong (like at least 70ksi) Loctite! I guess maybe on pot metal or whatever...though I believe Loctite says that unless both parts can rust, all bets are off.

I used it on an old motorcycle flywheel nut, it kept backing out so I put it on the crank threads, was good for a long time until I had to remove the flywheel for some other repairs, it pretty well took the threads off the crank but then again I didn't apply heat to it..

 

[82cabby]

So ran it today cutting some dry beech. Probably 16”-18”. Bolts held no problem.
Cut it fine but saw got very hot after two heavy cuts. Do I need to adjust the carb after going from ms310 to 390 size piston/ cylinder (maybe it was running lean?) or Did I work the saw too hard?

 

[Dennisthemenace]

Hi gang
I am replacing the cylinder on my ms310. The swap mostly went fine but there is one big problem: the bolts that hold the pan to the cylinder loosen up quickly when I start running it. Two reasons for this I think: I realized too late that I forgot the loctite. And I used replacement bolts instead of the stock. Soooo here are my questions:
do I need to use loctite primer for loctite 243? The website says it works on inactive metals without a primer but the box says use primer.
Second, can I switch back to the stock bolts even though the treads are different pitch? If you look in the picture you can see that the bolts have different thread pitches. The holes in the cylinder were not threaded so when I put in the replacement bolts they cut their own threads. Obviously I should have used the original ones first but I read some where that you should use new bolts when swapping the cylinder and these were the ones that were described as replacements when I ordered the parts.View attachment 918176

any help would be appreciated!

 

[Dennisthemenace]

I'd clean out the holes as good as possible, re use the originals with primer and 243 and hope for the best. OR drill and tap next size up, maybe 7/32

 

[arto_wa]

So ran it today cutting some dry beech. Probably 16”-18”. Bolts held no problem.
Cut it fine but saw got very hot after two heavy cuts. Do I need to adjust the carb after going from ms310 to 390 size piston/ cylinder (maybe it was running lean?) or Did I work the saw too hard?

Yes it needs readjusting - sounds like it was running too lean as would be expected.

 

[Jasonrkba]

I've been thinking of trying this.

Vibra-TITE 19960 Hot-Lock Extreme High Temperature Threadlocker, Translucent https://www.amazon.com/dp/B07XW2ZTZ...abc_2M7ESXF3R1KTK8Q9JH8E?_encoding=UTF8&psc=1