Ms500i or ms462

[andyshine77]

Go big or go home.[emoji13]

I personally have never seen a saw loose throttle response with any size outlet. I'm not saying can't happen, I've just never seen it.[emoji111]

 

[MustangMike]

My 10 mm 044 lost throttle response and did not idle smoothly with too much muffler opening, and I have seen 660s loose torque in the cut (not all of them), so I am cautions.

If I like the way a saw runs, I generally just leave it alone!

 

[andyshine77]

My 10 mm 044 lost throttle response and did not idle smoothly with too much muffler opening, and I have seen 660s loose torque in the cut (not all of them), so I am cautions.

If I like the way a saw runs, I generally just leave it alone!

You may have seen this already. http://chainsawrepair.createaforum.com/ported-saws/removing-spark-screens-does-it-make-a-difference/

Feeling this or that isn't something I put much faith in. Without a reliable dyno our options are limited to testing in the wood, which has inconsistencies in results as well. Other than some idling issues here and there with openings 90% or better, I have just have never seen anything negative power wise, in fact the opposite. [emoji111]

 

[MustangMike]

I took two nearly identical Asian 660s (w/Cross P+C) (I called them Asian Twins because you could not measure the difference in the port timing) and one I opened up the muff more than the other. The one with the open muff sounded stronger, had better throttle response, etc, but died in the cut (I was cutting a large very dead Chestnut [Rock] Oak log). So I changed the muffler to the same as the first saw and then I could lean on it just like the other one. To be honest, I thought the one with the open muffler sounded better and would be stronger, the results surprised me. However, in the wood it was very obvious I could not lean on it like the other one.

It all depends on the port timing, shape, etc, etc. I have learned there is no one hard and fast rule, each saw is different.

I know there are a ton of variables, but when the same person tests the same saw model, with the same B+C in the same wood, you can judge how long it takes to make a cut and how much you can lean on it.

Several other 660s have responded just the opposite for me. It really just depends on the saw.

The Asian Twins are the two strongest running Asian saws I built (w/o and port work), and were stronger than a lot of saws with port work. I lament that I had pre-sold both of them before I built them, but both owners are very happy with them.

 

[RI Chevy]

Maybe revisit that theory Mike if you still have the larger port muffler. See if you can replicate your findings.

 

[andyshine77]

Lots of variables indeed.

One thing I have noted, often times when you open them up really wide, when you load the saw the changing pitch is much more dramatic, so sometimes it sounds like the saw is getting loaded more than it actually is. Our perception can sometimes interfere with reality more than it helps.[emoji111]

 

[RI Chevy]

Good points Andy

 

[huskyboy]

Timing the cuts with the same b/c is what I would do

 

[RI Chevy]

YES!

 

[andyshine77]

Timing the cuts with the same b/c is what I would do

It's about the only opinion we have.

 

[dall]

You can not test mufflers without being on the same saw

 

[RI Chevy]

YES

 

[TreeLife]

For real testing, variables should remain as constant as possible. Same saw, same bar and chain, same log, same operator.

 

[MustangMike]

I did change it on the same saw and re test … I know how hard I leaned on it … I know how fast they cut (or not).

 

[RI Chevy]

YES!

 

[dall]

I did change it on the same saw and re test … I know how hard I leaned on it … I know how fast they cut (or not).

you need a new chain

 

[friendlywithbears]

Same socks too. I always forget that one.

 

[Woodpecker]

YES!

 

[MustangMike]

Maybe revisit that theory Mike if you still have the larger port muffler. See if you can replicate your findings.

From what I have seen, most people pick a muff mod they think will work and don't do any testing at all.

A modded muffler will likely always beat an unmodded (factory) one, but a mildly modded one may be better than an exgtremely modded one … just sayin!

Note: A lot of the mufflers that come on after market saws already have much larger openings than factory, and no screens, so they will already flow much better.

Jeff, you ran my Asian 660 at the GTG, I modded the baffle (but did not remove it) and left the ports as they were. Tell me that saw did not feel real good!

 

[RI Chevy]

It was very strong Mike. You did a good job.
Have you done any testing on that saw with larger muffler openings? Each saw is different. You MAY pick up even more. You'll never know without testing though.