Want My 045 to Think it's an 056 Magnum - Muffler Mod + ?

[bulletpruf]

Fellas -

Picked up a pretty clean 045 AVE from a member here several months ago and finally got around to it yesterday. It was inexpensive because it had no compression (60 psi). Picked up an NOS 52 mm P&C from another member here and swapped it out. Believe it's 81cc. And I'd like it to hang with the 056 Mag II that I got from another member.

So, I did the P&C swap yesterday. Nothing fancy, but I did delete the base gasket. I was rewarded with 198(!) psi compression.

On the muffler, I'm trying to figure out the best way to mod it. I could:

1. Redneck it and drill some holes in the front.
2. Hog out the exit at the bottom.
3. Cut it apart and hog out the internals. If I do this, I'm assuming I'd have to cut it in half with a Dremel, right?
4. Add an extra port. On the 056 Magnum there's a pipe that's used as an additional exit; I could fire up the MIG and try to add something similar.
5. Easier option might be to drill a big hole in the front and then just put a deflector on top. Might be prone to damage there however.

What about the ignition timing? I'm thinking advancing it would give it a bit of a boost, too, but I haven't changed the ignition timing on any of my saws.

Scott

 

[scottr]

Hey Scott , can you measure the bottom outlet of your 81cc saw ? I want to determine the outlet to displacement ratio .

 

[bulletpruf]

Hey Scott , can you measure to bottom outlet of your 81cc saw ? I want to determine the outlet to displacement ratio .

You want me to measure the exhaust outlet, right?

 

[scottr]

Yes .

 

[Mad Professor]

For muffler mod you could do a "Lakeside" extra ex port using an extra hole and welding in a piece of tubing that will accept stihl blower spark screen parts. You can point it in any direction you wish.

Do a search on this, I believe the original thread was on a 361 stihl. Pictures are gone but great description.

 

[bulletpruf]

For muffler mod you could do a "Lakeside" extra ex port using an extra hole and welding in a piece of tubing that will accept stihl blower spark screen parts. You can point it in any direction you wish.

Do a search on this, I believe the original thread was on a 361 stihl. Pictures are gone but great description.

I'm familiar with the Lakeside mod. Just not sure I want to spend that much time/effort. Thanks

 

[Mad Professor]

I'm familiar with the Lakeside mod. Just not sure I want to spend that much time/effort. Thanks

If you have a Mig, a drill, and some bits.............it won't take much time/effort compared to a "cob job".

 

[bulletpruf]

If you have a Mig, a drill, and some bits.............it won't take much time/effort compared to a "cob job".

Point taken. What should I source to use for the pipe?

 

[Mad Professor]

Point taken. What should I source to use for the pipe?

You need correct ID and OD for screen to fit. Original thread Andy used 3/8" black pipe and drilled out inside then turned down outside. Easy with a lathe, or use a drill press to drill out inside, then chuck it and turn down outside with a file. Start with enough pipe so you can cut into pieces and have a stock for several.

You might be able to source a direct fit from someplace like McMaster but for a small amount will pay large $$$

Also don't need Mig, torches and brass will work too.

I've got a BR400 so could measure up the outlet but it is put up for the winter.

From original thread:

https://www.arboristsite.com/community/threads/lakeside53s-361-muffler-mod-w-photos.33528/

post #19

The easiest solution to adding a port is simple to drill a hole and insert a tube. Covering this with a screen is a poor choice as the surface area of the screen is small. Stihl solved this problem on the BR400/420/340/380 series of blowers (as far back as 1992 on the BR 400) by inserting a tube of screen material into the pipe. It folds back over the pipe and is secured by a clip. The screen is many times the area of the outlet, so flow restriction even with some blockage is minimal.

This can be used on any almost any saw where you need a spark arrester and are adding a port (so long as you have room inside). You can of course choose not to fit it, but so long as the tube is the correct dimension, you have the option of putting it back in!

There are two basic sizes available: One fits over a 14mm OD (roughly 1/2 inch ID) pipe and the othe over a 16mm OD thin wall pipe. The picture shows the 14mm version. I'll have the 16mm version is a day or so and will likely use this as the pipe is thin wall 9/16 ID tube will work and is easier to find (for me).

Part numbers:

14mm version (BR420 etc blower)
Screen - 4203 141 9005 $5.56
Clip - 4203 141 6600 $2.00

16mm version (TS 400 Cut-off saw)
Screen - 4223 141 9000 $4.25
Clip - 4223 141 6600 $3.25


I did not need to tear the muffler apart to do this modification. The only reason I did was to educate myself on the internals and space constraints. In the future, it's just drill a hole at 45 degrees, grind the bottom of a short tube at 45 (so the screen has maximum area inside the muffer), and braze it on. For those of you intimidated by the thought of brazing, it is dead easy and can be done with Mapp gas available at your local hardware store.

The easiest way to drill a big hole at 45 degrees in thin metal is to use a uni-bit or one of the cheaper clones. They look like this :

Here's the muffler back together (heated the crimp area "red" and crimped it back together):

This is what the 14mm screen looks like inside the muffler. The 16mm is longer.

Here's the completed muffler on the saw. The factory spark arrester and exhaust port are unmodified. Heck you could even put it back to "factory" by plugging the new port!

One nice coat of matt exhaust paint and a quick bake (450F for an hour in the convection oven!) and it's one tough coating and ready for work. Hmmm, looks like factory stock to me.

Questions? Improvements?

 

[bulletpruf]

Thanks, MP! Guess I have my work cut out for me!

Scott

 

[Mad Professor]

If you find some generic steel tubing that works with either screen please post source. It might be sitting on the shelves of a local hardware store?

P.S. this also concerns the importance of keeping those screens clean on both stock and modded mufflers. My blower started acting funny a few years ago and I was stumped. Tried plugs, carb adj. .....etc. I was going to pull muffler to have a look at P/C and lo and behold, the screen was dirty. Same has happened on a Husky string trimmer.

Now that I think of it, I should check all of my saws I've not been inside in a while........

 

[Mad Professor]

Looked-at McMaster.

For the 9/16 I.D. stainless

O.D. Thickness I.D. Press Temp part # 1 ft 3ft 6ft

3/4" 0.083" 0.584" 3,700 psi @ 72° F -425° to 1500° Soft 89895K761 16.86 37.0 67.44

 

[bulletpruf]

Thanks, MP. I'll check out the local hardware store and see what I can find.