ms 361 muffler mod...my 2 cents

[041fboss]

Just completed the muffler mod that Lakeside53 suggested...Works great but I found that putting the ts 400 spark arr. really slowed it down. Any one else have this trouble?

 

[Lakeside53]

Not me.

"slow it down"? you mean WOT or cut speed? Sure there is some additional back pressure from the screen and you would need to retune slightly, but... the screen is many times the area of the outlet.


Is your outlet tube flush with the inside of the muffler or did you extend it into the casing?

 

[041fboss]

It felt like it had less torque with the spark arr. Dialed with and without in with tach. The pipe is flush with the muffler. Maybe the louder sound makes it feel like it is more powerful?

 

[Lakeside53]

Louder with the screen in in/out? Never really noticed much difference.

If you're concerned, time some cuts, but retune each time. I assume you did take the limter caps out and adjusted the H&L your screws? Where do you have your WOT rpm set?

 

[041fboss]

Lakeside53, what kind of horsepower increase do you think the mod makes? I have been researching the 361 muf mod for some time now. And would like to thank you for all of your postings. Takes a lot of time to research and then post what you did. Sounds tuff as nails also. Thanks

 

[041fboss]

rpm 13700. Louder with spark arr. out. Yes i adjusted the h and l ... what are these caps everybody is talking about. I put a screw driver right in and started turning?

 

[Lakeside53]

You can't turn the screw underneath beyond their limited range without removing the caps.

If you are at 13,700, how did you get it that low without removing the cap?

 

[041fboss]

Remember Im new at tuning 2 cycles. So let me get this correct. You can turn the screws a limited range unless you remove the caps... then you can turn the screws a lot more. I dont know how I got 13700 if the caps are still in? Help me. Its a new saw 20 tanks of gas threw it. And I have never touched the caps...if there is any. Thanks

 

[Lakeside53]

The 361 I've retuned after a muffler mod required an 1/8 to a 1/4 turn beyond the "std 1 turn" setting (in place before the limiter cap was installed) to get them down to 14k.

Use "search" and look for threads on "361 limiter caps"

 

[041fboss]

Thanks very much for the help! 041FBOSS

 

[041fboss]

Just checked the saw it has caps. Removed the H cap. Do I need to remove the L cap to tune correctely. Wound up like crazy without a cap. holy cow.

 

[041fboss]

What rpm is recommended?

 

[Lakeside53]

Depends on how close to the edge you like to run... 14-14,500 seems like a decent number with a 20 inch bar. Closer to 14k with a 25 inch bar..

 

[041fboss]

Over the edge. Ha ...Do I need to remove the L cap to correctly tune?

 

[Lakeside53]

Maybe...

I do. Just take out both caps, slice off the tab on the side, and reinsert. them. You never have to worry about them again.

 

[041fboss]

I destroyed the first cap...H screw. I got rammy.

 

[Lakeside53]

yep... 50 cents each... buy two new caps...

 

[blsnelling]

You need the caps on there for friction to keep the screws from turning during use. There are no springs on the screws. Trim the little tabs off the new ones and install them. You'll have full tuning capability and not have to worry about it loosing tune.

 

[041fboss]

Will get two new caps...what a joke...little different than the old 041. Did some more playing with the saw today. Over all I feel that the grunt or torque on the saw was greatly improved. Thanks to both of you for the carp cap advise. Has anybody thought about plugging the stock exhaust hole and making the other exhaust port (new port) around 3/4 of an inch or 7/8? just a thought

 

[djohn]

I haven't done anything with the existing exhaust hole where it comes out of the muffler but I did open the tube that goes to the hole on the end where it was rolled. It is now the full ID of the tube at the end.