Ms 460 with nwp cylinder help

[Normzilla]

A friend wanted me to help him, get his ms 460 going. He ported it was running great. Then starved out one day. I got it running with effort. Immediately sensed air leak. Found a couple loose cylinder bolts. Tightened them down. Do you guys lock tight them, or get them just good and tight? How common is this? I've never had cylinder bolts back out. But all my saws are stock. Thanks Norm....

 

[Deets066]

He probly forgot to tighten them all the way. Stihl bolts never back out if they are tight, especially the cylinder bolts. It usually takes quite a bit of effort to break those loose. Even if they were just installed.

 

[huskihl]

He probly forgot to tighten them all the way. Stihl bolts never back out if they are tight, especially the cylinder bolts. It usually takes quite a bit of effort to break those loose. Even if they were just installed.

+1. I suppose if they were tight, but not real tight, the gasket may have compressed a bit and loosened things up though. Crank them down tight and they stay

 

[Normzilla]

Thank you both. I was wondering that to maybe after break in, heating and settling.

 

[Normzilla]

So never light duty lock tight?

 

[huskihl]

So never light duty lock tight?

You can. Doesn't hurt. I use red on big huskies and it works fine. Blue or green would be fine for what you're doing

 

[Deets066]

I use to use blue all the time, it doesn't hurt a thing

 

[panteliss]

I never have see a screw , nut , or bolt have problem on stihl's

but on husqvarna's ................. beter to have yours screws box with you specially when you are out in the forest

 

[Normzilla]

Thank u all....

 

[Deets066]

Anytime Norm

 

[panteliss]

Thank u all....

the cylinder screws are M5 but the oems have more deep and agressive threads specially designed for materials like alu , or magnesium

so if someone before use screws M5x 08 ( simple screws from the local shop ) he have make problem on the threads inside the crankase

this is one reason that the screws seems tight but loose after and the loctites usually cant help

just right now i have the same problem on a husqvarna 372 mufler the oem screw stay but the other ( the simple ) loose after of 15 minutes use

 

[jacob j.]

Stihl assembly technicians use red Loctite at the factory and I stick with that on cylinder base screws. As Deets said though, Stihl torx screws rarely ever back out because of the locking "teeth" on the underside of the head. If your friend used hex head screws then that could be part of the issue.

 

[Normzilla]

Stihl assembly technicians use red Loctite at the factory and I stick with that on cylinder base screws. As Deets said though, Stihl torx screws rarely ever back out because of the locking "teeth" on the underside of the head. If your friend used hex head screws then that could be part of the issue.

Thanks buddy. No torx, I think he didn't have the right took. I fixed it though.