New Tach and Tach tuning

[Beer Gut]

My Tach came in today and I put it to use and was surprised at the results. All readings were taken several times and all saws were hot.

044 bought in 1997 was still set from factory Tached out at 12,300 WOT. I adjusted and left it 2,700 rpm idle and about 13,300 rpm WOT it sounded best there.

460 which I rebuilt from ground up and ear tuned myself was the worst Tached out a 11,800 WOT :msp_unsure: I suck. Adjusted to 2,700 rpm idle and 13,500 rpm WOT, saw is obviously faster still getting 4 stroke sound.

660 bought new this summer still set from factory was Taching out at 12,500 WOT and 2,900 rpm idle. Adjusted idle down to 2,700 rpm and left it at 13,000 WOT sounds good there and may be best since saw is still breaking in.

The good news is that they were all a little rich and not running lean all this time. The 044 and 460 are waiting on parts for muffler mods and will have to be retuned anyway but I will take the Tach with me when I cut this week and take some readings and listen after I work them awhile.

 

[bayard]

rpm

what kind did you get and how much.thanks k

 

[Beer Gut]

what kind did you get and how much.thanks k

Fast Tach from Edge and Engine very simple I like it:msp_thumbsup:

 

[Beer Gut]

what kind did you get and how much.thanks k

Sorry you asked how much 85.00$ 92.00$ with shipping and tax got it in 3 days

 

[komatsuvarna]

Thats a good tach. I got one of them too from edge and engine. I believe they are a site sponsor too.

 

[REJ2]

Thats a good tach. I got one of them too from edge and engine. I believe they are a site sponsor too.

It is, and they are, was playing with mine yesterday!!

 

[o8f150]

It is, and they are, was playing with mine yesterday!!

i have to ask,,playing with your hangy down thing or the tac????:hmm3grin2orange::hmm3grin2orange::hmm3grin2orange:

 

[huskydude]

i'm still learning optimum tune by ear. i find i leave them too rich. today was nice because I sold a friend a 2171 and I could hear him cutting so I knew I had to lean it out. much easier to tell listening from afar.

 

[REJ2]

i have to ask,,playing with your hangy down thing or the tac????:hmm3grin2orange::hmm3grin2orange::hmm3grin2orange:

Dam, left myself open on that one!!

 

[Beer Gut]

i'm still learning optimum tune by ear. i find i leave them too rich. today was nice because I sold a friend a 2171 and I could hear him cutting so I knew I had to lean it out. much easier to tell listening from afar.

Me too the Tach really helps I get close but leave it rich. The tach helped me get that last bit I have trouble hearing or I guess I can but am unsure to push it farther.

 

[o8f150]

Dam, left myself open on that one!!

you sure did:biggrin::biggrin::biggrin::biggrin::biggrin:

 

[o8f150]

i'm still learning optimum tune by ear. i find i leave them too rich. today was nice because I sold a friend a 2171 and I could hear him cutting so I knew I had to lean it out. much easier to tell listening from afar.

i got my tach a few weeks ago,, i tached my huskies,, i thought i had mine pretty close too but they where pig rich,, glad i have a tach now

 

[komatsuvarna]

I tune mine by ear in and out of the cut, I still like having a tach to check myself though. Comes in real handy on weed wackers and leaf blowers too.:smile2: Probably one of the best tools Ive bought.

 

[Sdh1218]

Might be a stupid question

Might be a stupid question but I'm new to saws and 2 stroke engines. But how does useing a tach tell you the engine is running rich?

 

[komatsuvarna]

Might be a stupid question but I'm new to saws and 2 stroke engines. But how does useing a tach tell you the engine is running rich?

The RPMs. The richer they are, the less rpms they turn. Every saw has a factory spec on max rpms. :smile2:

 

[Sdh1218]

The RPMs. The richer they are, the less rpms they turn. Every saw has a factory spec on max rpms. :smile2:

Thanks for the info. That's what I kind of thought but wanted to make sure.

 

[Agoraphobia]

This fits here, so I'll ask:
Do I have this correct

Need to richen when: O2 density increases, so at Sea Level or lower elevation, On dry days (low humidity), and when cold.

Need to lean when: O2 density decreases, at higher elevations, at higher humidity levels, when hot.

So if a rank amateur was going to tune once for the season they would be much better off tuning at the lowest altitude they will cut at, on a dry (low humidity) day that is as cold as they are likely to cut on. That way they are at the conditions that require the richest settings and seasonal fluctuations shouldn't phase them or ruin their saw.

Where as if they tuned at high elevation on a hot, humid day, they risk running lean when any or heaven forbid all three conditions change?

Do I have that right? I don't intend on actually doing this (only tuning once for the season), but I want to make sure I understand the variables correctly.

 

[Steveo_supremo]

Yes, you have it right.

 

[ZeroJunk]

You guys make sure that you tach those saws after they have been running for a while, are at operating temperature, and have burnt off all the excess fuel in the crankcase. They will climb.

 

[WidowMaker]

The RPMs. The richer they are, the less rpms they turn. Every saw has a factory spec on max rpms. :smile2:

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But don't the factory spec go out the window once a saw has been modified...otherwise whats the point...