4-Stroking

[Kinburnjim]

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

 

[CTYank]

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

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]

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

 

[redfin]

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

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

 

[firefighterwolf]

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

Copy this: 5BZkB9QQTJU

Go to youtube and paste into the search bar.

 

[Lark-o]

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?

 

[Kinburnjim]

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 (?)

 

[tolman_paul]

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.

 

[RedneckChainsawRepair]

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]

 

[redfin]

Copy this: 5BZkB9QQTJU

Go to youtube and paste into the search bar.

Thank you

 

[Kinburnjim]

Thanks for the help and videos. Clears things up.

 

[chadihman]

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]

 

[Evan]

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

 

[Ymountainman]

4stroking in the cut, when i lift?

http://youtu.be/f-lOpUY4us0

 

[o8f150]

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>