ported 661 baffle in muffler vs baffle out

[jmssaws]

I don't think i'll have time to build a short bar saw. we'll just bring what we have and enjoy the day.

I don't have a any bar saw but would prefer to build a long bar saw,less grinding

 

[Mastermind]

I thought that's why we are trying to meet up in iowa,I'll bring the gimp suit

We are gonna need videos.

Just sayin.....

 

[tree monkey]

better bring your camera

 

[awol]

Can I bring a 661 and join in?!

Oh, and also a good 390...........????

 

[paragonbuilder]

Can I bring a 661 and join in?!

Oh, and also a good 390...........????

I would love to see one of your 390's smoke the 661's Alan!


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[tree monkey]

yep yep

 

[Deets066]

I would love to see one of your 390's smoke the 661's Alan!


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It could happen

 

[awol]

It could happen

Yep yep!

I sold that 2188, but I can do another one......

 

[Moparmyway]

I find this interesting, my saws run 13,600 to 13,800 mtronic, and 14.200 on carb. no poping

OK
I’m dredging up and old thread

BUT

I do believe that I’ve figured out this popping stuff

@tree monkey
And anyone else who wants to join in


What does this 661


562



346



all have in common ?

There are actually 3 correct answers



Fire away

 

[MustangMike]

1) Dual port exhaust

2) Timing Advance

3 Port work???

 

[Moparmyway]

1) Dual port exhaust

2) Timing Advance

3 Port work???

1. Yes
(this is a conditional yes, the 346 already had a dual port exhaust, but in different configurations)

2. No
661 has timing advanced
562 is stock except for the muffler mods
346 has timing advanced

3. No
661 is ported
562 only has a muffler mod (already had a muffler mod exiting out the factory area, but widened out to the deflector)
346 is ported, and has had 2 different dual port exhausts

 

[trooney]

1. They are chainsaws
2.They all cut wood
3. They are all runners

My best guess!! Lol

 

[huskyboy]

OK
I’m dredging up and old thread

BUT

I do believe that I’ve figured out this popping stuff

@tree monkey
And anyone else who wants to join in


What does this 661
View attachment 236639 View attachment 236638

562

View attachment 236640

346

View attachment 236637

all have in common ?

There are actually 3 correct answers



Fire away

Loud, smelly and scary.

 

[MustangMike]

What ever happened with the big saw shootout??? We changed gears here after the pause!

 

[Moparmyway]

What ever happened with the big saw shootout??? We changed gears here after the pause!

Jason destroys saws, and isn’t a member here anymore. He’s been banned from many other forums too because of this.


I brought this thread back, not to re-visit the nightmares people have been through, but because of the 3 things that these saws all have in common now.

1. They all “pop” through the exhaust when under partial load at full throttle

2. They all started with this popping, after getting, what most would consider, way too large of a muffler mod.

3. They all stop popping when a “normal” modded muffler is put on them, or when they are under enough load with these no restriction mufflers

 

[RI Chevy]

Need carb adjustments inside?

 

[Moparmyway]

Need carb adjustments inside?

Absolutely Jeff, anytime you change the enviornment a saw is in, you need to re-tune, ceptin 2 of these saws tune themselves

 

[RI Chevy]

Yes sir. I realize the retune. But I was thinking maybe some adjustment inside the carb. Pop off pressure, etc? Just kind of thinking outloud here.
What exactly is it that causes this popping?

 

[Moparmyway]

Just a quick carb tune for the 346 Jeff

I believe it is excess fuel getting enough oxygen to light off in or near the exit of the muffler.

Reset the 661 or change to a shorter bar and it pops like crazy for a little bit, then she tunes herself a bit and it’s around during partial loads. That’s a pretty good indication, to me at least, that it’s fuel related. I’ve gone too far on timing and you can feel the saw twitch on you when that happens, this is different. There’s no twitching and they’re all running smoothe as silk.

 

[RI Chevy]

Hmmm. Interesting. So you actually have to lean it out to get rid of the popping?
Very odd.