Tachometer........ Buy One Or Not???

[shadow745]

Regarding 2 cycle engines, I own a chainsaw, 1 string trimmer and a brushcutter. I have always tuned the trimmer and brushcutter by ear and performance, but since buying the saw I have considered buying a tachometer to really fine tune them according to factory specs. But maybe that really only applies to fairly new equipment and the brushcutter has hundreds of hours on it. Question is should I spend $50+ on a decent tach or tune them by ear and performance since I only have the three 2 cycle engines? Thanks for any info. Later!

 

[davefr]

Regarding 2 cycle engines, I own a chainsaw, 1 string trimmer and a brushcutter. I have always tuned the trimmer and brushcutter by ear and performance, but since buying the saw I have considered buying a tachometer to really fine tune them according to factory specs. But maybe that really only applies to fairly new equipment and the brushcutter has hundreds of hours on it. Question is should I spend $50+ on a decent tach or tune them by ear and performance since I only have the three 2 cycle engines? Thanks for any info. Later!

Older 2 cycle equipment can be tuned by ear. (ex: 038) Some of the latest crop of high RPM chainsaws can only be tuned accurately with a tach. And there are some other saws (ie 7900) that need a combination of ear, tach, timed cuts and divine intervention to get right.

You need to decide based on your equipment.

 

[danrclem]

You might as well go ahead and get one. When you start thinking about wether you need one or not the decision is all but over. You won't stop thinking about it until you do get one.

How do I know. The same thing happened to me.

 

[2wheels]

Don't was your time and money. If it is tuned right and sounds true the log will not care what your RPM is.

 

[milkie62]

I kicked the idea around for quite some time.I finally said "GO FOR IT".I should be getting it in a couple of days along with Amicks 10 chain special .

 

[B_Turner]

More information is generally better. Like RPM. Especially in this day of limited coils.

I personally would not be without one in the toolbox.

It should not get in the way of common sense, though.

 

[Nitroman]

I like mine!

Hook it up and then wind it up, and with a slight turn of the screw, you're there.

 

[gafirefighter]

I have been tossing around the same idea lately, and I think I have come to the same conclusion that you have. As soon as I can afford it I will be picking one up myself. I guess you never can have too many tools.

Adam

 

[alderman]

Go for it

I kicked around the idea for awhile and finally picked one up off e-bay. I'm not a mechanic by any means and don't have a clue about tuning by ear, but numbers come pretty easy to me and it's a neat little item when you want to find out what the equipment is really running.

 

[Stihl051master]

Not to try and hi-jack your thread, but I have also been considering a tach. What would your recommendations be for a reasonably priced one? I have been looking at the Sen-dec ones out of Baileys. Is there something better out there in this price range? Anyone use one of these? Is it a good quality tach?

 

[KMB]

I kicked around the idea for awhile and finally picked one up off e-bay. I'm not a mechanic by any means and don't have a clue about tuning by ear, but numbers come pretty easy to me and it's a neat little item when you want to find out what the equipment is really running.

Almost the same story as mine. I can do a little mechanic work to get by, but wouldn't call myself a mechanic . I thought I had my muffler modded 260 tuned by ear...I found I had a LOT to learn after I got my tach and found out how off I was. The saw was tuned to rich, I guess I'd rather have that than to lean...but I've read that way to rich isn't good either.

Kevin

 

[excess650]

I held off until I couldn't stand it and didin't want to risk damage any longer. Mine should be here tomorrow.

My thinking is that one of the better tachs that updates quickly is the way to go. Waiting 5 seconds to update a 2 stroke is too long, In my opinion.

I tuned my old Mac PM610, string trimmer, and another saw or two by ear, but would feel better with the newer, high rpm saws tuning by tach.

 

[TRI955]

I picked one up to tune my 260 with, I was way off by doing it by ear!!!! I would have never realized the improvement of my muffler mod without it. 14,000 rpm is screaming!!!!!!

 

[cjcocn]

The last two posts about say it all.

I bought myself a tach so that I never have to wonder if my RPMs are where they should be. Maybe my ear would do (I highly doubt it!), but when I tach something then I know it is tuned properly.

 

[serial killer]

I only have the three 2 cycle engines?

This is the heart of the problem. I remember an article by Brock Yates in Car and Driver that suggested that the measure of a man was in his internal combustion cylinder quotient. What you need to do is immediately buy more machines until you are more than justified in buying a tach to maintain them. Only then, with four cars, a dozen lawnmowers, and 30 chainsaws will you truly be near the top of the food chain.

 

[davefr]

The last two posts about say it all.

I bought myself a tach so that I never have to wonder if my RPMs are where they should be. Maybe my ear would do (I highly doubt it!), but when I tach something then I know it is tuned properly.

Hate to break the news to you but RPM doesn't guarantee proper tune. I was under the same impression.

Another member reminded me of other factors effecting tune such as load. (ex: tune your saw to the RPM spec using a long bar then throw on a short bar and you're now in lean seize territory). The tach. is a great tool but not a guarantee.

 

[Dan Forsh]

Hate to break the news to you but RPM doesn't guarantee proper tune. I was under the same impression.

Another member reminded me of other factors effecting tune such as load. (ex: tune your saw to the RPM spec using a long bar then throw on a short bar and you're now in lean seize territory). The tach. is a great tool but not a guarantee.

Scare monger!

You would need a pretty big difference in bar length to go from good to seize.

And even then, if you are tuning by ear you would still have to reach from that screwdriver again.

 

[nap69]

I bought the Tiny Tach wireless fast refresh model to help me learn how to set my saws and give me a little bit of peace of mind cos rubbish at tuning by ear...........worth every penny!!





Makita/Dolmar 111/115 x5(you can never have too many spares!!)
Stihl 038 mag x2
Makita/Dolmar 7900 imminent!!

One of the 038 mags may have to go!!

 

[cjcocn]

Hate to break the news to you but RPM doesn't guarantee proper tune. I was under the same impression.

Another member reminded me of other factors effecting tune such as load. (ex: tune your saw to the RPM spec using a long bar then throw on a short bar and you're now in lean seize territory). The tach. is a great tool but not a guarantee.

Well as far as bars go, I'm pretty straightforward in that each of my 3 saws only have one bar. Once it is set for that bar, there is no changing bars for me.

I see by your sig that you have many more saws than I do, and I will hazard a guess that you fit into that group of (at least) 95% of AS members who know much more about saws than I do. Therefore I will continue by saying .....

Changing altitude is another factor that I've read about on AS, but I do not believe that it applies in my case as it is quite flat here.

Running with a dirty filter is another way to potentially ruin a saw by leaning it out, but I try and keep my filters clean.

I keep my chains sharp so that the saw doesn't have to work too hard.

I also keep my saws clean overall so that they do not get too hot (clean the cylinder fins, etc).

Considering that I tach both the H and L screws as well as the idle screw (that "bottoms out" against the throttle linkage), what other factors should I be looking at?

This certainly isn't meant as a challenge, but instead is my wanting to learn more so that I don't bugger up my saws.

Thanks!

 

[Dan Forsh]

Running with a dirty filter is another way to potentially ruin a saw by leaning it out, but I try and keep my filters clean.

I'll just pick you up on this one point.

Running with a blocked/dirty air filter does not cause a lean condition.

Think about it, lean = too much air and not enough fuel

A block filter means not enough air

Therefore you are running rich