Spark arrester for MS261

[atpchas]

I have an arrester-less ms261 muffler I'd like to use for a rebuild. The fire risk here means I want to and must add an arrester. This muffler never had an arrester, so it's an add, not replace. There are tons of threads about removing arresters, but I seek suggestions for adding one. I'm more interested in reliability and effectiveness, less motivated by appearance. My initial thought is to enlarge the exit hole a bit, then cut a piece of screen that will fit tightly under the deflector and secure it with a screw. If I go this route (if no one proposes a better alternative), what is the best way to secure the screw so the screw does not vibrate loose?

 

[Mad Professor]

Years back there was a thread by Lakeside53 modding a 361 muffler. Pictures got lost in the site crash.

https://www.arboristsite.com/threads/lakeside53s-361-muffler-mod-w-photos.33528/
https://www.arboristsite.com/threads/361-muffler-mod.57089/
He welded/brazed short sections of steel tubing onto the muffler, then used spark screens from Stihl blowers. I know there are two different sizes for different blowers but don't know the I.D. O.D. diameter(s). The screens fit inside the tubing and are secured with a clamp on the outside. You can add more than 1 and point the tubing as you wish.

Parts #20 and 21

 

[atpchas]

Years back there was a thread by Lakeside53 modding a 361 muffler. Pictures got lost in the site crash.

He welded/brazed short sections of steel tubing onto the muffler, then used spark screens from Stihl blowers. I know there are two different sizes for different blowers but don't know the I.D. O.D. diameter(s). The screens fit inside the tubing and are secured with a clamp on the outside. You can add more than 1 and point the tubing as you wish.

I remember that thread. A wonderful suggestion, but my lack of welding/brazing skills and the geometry of the muffler make this not a solution I can implement.

 

[Mad Professor]

I remember that thread. A wonderful suggestion, but my lack of welding/brazing skills and the geometry of the muffler make this not a solution I can implement.

Real easy to do in brass. You can orient the tubing as you wish.

If you did the fabrication wouldn't cost much for someone to braze/weld it up.

Learned those skills in High School Shop classes.

 

[farmer steve]

I have an arrester-less ms261 muffler I'd like to use for a rebuild. The fire risk here means I want to and must add an arrester. This muffler never had an arrester, so it's an add, not replace. There are tons of threads about removing arresters, but I seek suggestions for adding one. I'm more interested in reliability and effectiveness, less motivated by appearance. My initial thought is to enlarge the exit hole a bit, then cut a piece of screen that will fit tightly under the deflector and secure it with a screw. If I go this route (if no one proposes a better alternative), what is the best way to secure the screw so the screw does not vibrate loose?

Not sure if this would work for your muffler or not. https://eganperformancesaws.com/products/exhaust-deflector-new-mild-steele

 

[atpchas]

Learned those skills in High School Shop classes

Sadly, not a class my small parochial high school offered in the early 60s.

Not sure if this would work for your muffler or not. https://eganperformancesaws.com/products/exhaust-deflector-new-mild-steele

Thanks for the link. I may look for a way to work that into the project.