4-Stroking

Hi all,

Would anyone have a link to a video on proper carb tuning that has a decent audio so I can hear true 4-stroking once and for all? I just got one of my saws back after a carb re-build and to me it sounds like it is running lean or maybe I have been running it too rich for so long I don't know the difference. Any help to my edumacation process would be greatly appreciated.

Jim

Kinburnjim said:

Hi all,

Would anyone have a link to a video on proper carb tuning that has a decent audio so I can hear true 4-stroking once and for all? I just got one of my saws back after a carb re-build and to me it sounds like it is running lean or maybe I have been running it too rich for so long I don't know the difference. Any help to my edumacation process would be greatly appreciated.

Jim

Click to expand...

Strictly speaking, it's not 4-stroking. Could be more like 4-, 6-, and 8-stroking mix.

2-stroking means it's firing consistently at every opportunity- it's "on song." Nice clean exhaust note.

4-stroking means it's "off song"- not firing consistently. Sounds asthmatic.

I've no idea what "sounds like it is running lean" means.

At its best, it should be 2-stroking @WOT under load, with some 4-stroking when you lift @WOT. You need both parts of that.

jtracy1223 said:

http://www.arboristsite.com/chainsaw/113538.htm

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That vidoe never appears for me. I'd love to watch it.

redfin said:

That vidoe never appears for me. I'd love to watch it.

Click to expand...

Copy this: 5BZkB9QQTJU

Go to youtube and paste into the search bar.

know the difference between 4-stroking and being on the rev limiter also. They can sound similar if you don't know what youre hearing. what saw are you tuning?

it's a J'Red 670 Super II. By running lean, I mean that it sounds like it is running at max RPM without the burble (?)

Burbling and fat is probably a better description than 4 stroking, but if you don't know what you are listening for, then it doesn't really help. A rev limiter sounds different than a 2-stroke that is too rich, it's more like a bad vibration.

Here is a super fat 4 stroking 166 I had, hear it out of the wood fat fat fat. Then listen to it when it hits the wood and starts clearing up. Thats how I likem, 4 stroking and clear up in the cut.


[video=youtube_share;YqXOHsQE3Wk]http://youtu.be/YqXOHsQE3Wk[/video]

firefighterwolf said:

Copy this: 5BZkB9QQTJU

Go to youtube and paste into the search bar.

Click to expand...

Thank you

Thanks for the help and videos. Clears things up.

This is my 460 on my dyno listen closely and replay from 20-30 seconds into video. You can hear the switch from four stroking to two stroking. I tuned that one fat as that was the first run on the dyno.[video=youtube_share;VGpxVzkYU70]http://youtu.be/VGpxVzkYU70[/video]

lean sounds like a pissed of sewing maching with no top end

watched that dyno vid and didn't realy hear fourstroking till just before 2;40. must not have been a load on the saw at this point

id love to see the dyno readings. on this contraption

4stroking in the cut, when i lift?

http://youtu.be/f-lOpUY4us0

it is 2 stroking x 2:msp_biggrin::msp_biggrin::msp_biggrin: here is the vid I did on tuning,,, dang I miss those earthquakes:bang:

<iframe width="420" height="315" src="//www.youtube.com/embed/2HLpx5mqvW8" frameborder="0" allowfullscreen></iframe>