Echo CS-341 Muffler Flow bench testing

[Team FAST]

Howdy,

Been a little while so I thought I would post today's shop fun. My trusty little Echo CS-341 was in need of some spring maintenance so I took the opportunity to upgrade the muffler. This saw came with a catalyst muffler which always has seemed restrictive. Turns out the CS-3400 saw was the model made before catalytic converters (so it will run good on regular gas...lol)

I ordered a used CS-3400 muffler on ebay for evaluation. Turns our to be an exact replacement...without the restrictive cat. See the pics

 

[Stihl 041S]

Great to see you again.
The flow bench threads are great!!!

 

[Team FAST]

I cleaned up the CS-3400 muffler with my soda blaster. The muffler is not crimped or brazed, making it very easy to disassemble the halves. Inside is a baffle with four holes on one side and a rectangular opening on the other. Spark arrester screens are identical.

 

[Team FAST]

Here they are mounted on the flow bench. The obvious first test after getting a stock baseline is to remove the spark arrester screens. I am not an advocate of doing this when installed on the saw, so I show the data here for informational purposes. I leave the screens installed on mine.

 

[Team FAST]

Here are the results along with the air data collected at the time of the test.

The CS-3400 muffler flows 30% more than the CS-341 Cat muffler. 2.5 CFM improvement doing nothing else. It is an easy bolt on muffler mod! The muffler openings and baffle cross sectional areas are well matched. I don't think there is any benefit to opening up the holes in the baffle or any of the other holes. It is a pretty free flowing design. If you start hogging it out, you will lose backpressure and performance.

i will test the saw this weekend.