rotary Archer Digital Engine Tachometer Replaces Echo 99051130017

Works great.

Saw an unsolicited review on YouTube by Chickanic. Item measures RPM accurately and updates quickly. Very simple to use. Although the battery is soldered in place as others have mentioned, Lithium button cell batteries are available with solder tabs for those who are so inclined to replace their own. Available right here on Amazon, in fact.

Great meter. I use mine for setting the idle speed on my Echo two cycle engine. JUST BUY IT! you will love it.

This was used to tune up a number of chainsaws and a couple of trimmers. I saw this sort of unit used on a YouTube video, was unaware there was anything like it out there. It can be used free standing, holding next to a spark plug or there's a clip-on antenna wire for the spark plug wire, we used that mode since we needed hands free to adjust the carb needles. It has a couple of modes, one for cylinder one on two cycles and 4 cycles and one for cylinder two for same. Cylinder one has the widest rpm range. Had no twin engines to tune, used the first mode and the unit sat on the bench. Managed to rev one chainsaw up to 15K, that's excessive and turned it back to 12K. Started out at 8K and my b-in-l said it was bogging down when at open throttle. Way better than just a calibrated ear. The needle tweak was almost imperceptible. All units drained and hung up for the winter after tuning.Marked down one star for not having a readily replaceable battery. Case is well-screwed shut. Probably soldered down. I can deal with that when the time comes.Has rudimentary instructions with it, those plus YouTube videos are all that's needed to use. This replaces a genuine Echo part number about $50 more and out of stock. There is no case, I used a cheap plastic pencil box from WalMart to store this and the set of carb diddle sticks I got from Amazon. Those are much better than trying to jam a screwdriver into the needle slots, recommended to get, were cheap. Nice having the tools for the job.

My unit came in a box that had tape on the top flaps of the box. Condition of the box was a little beat up. I cut the tape , and the bubble wrap bag was opened and torn. To me, this was obviously a unit that was opened, and then returned. Nothing was missing. Box contained antenna lead with clip, and carrying strap. I went to my shed, and started my old lawn boy two stroke. Unit worked perfectly well, wirelessly, and with the lead. I then tried it on my red Max blower, and then on my four stroke lawnmower, with a twin cylinder, and on my four cylinder car. The unit worked well, and seemed accurate on everything that I tested. I gave it three stars for two reasons. First, and foremost, is the fact that this unit was obviously returned by a previous buyer, repackaged, and sent on to me. I expect to have a factory sealed box, when I make a purchase. The second reason that I gave it 3 stars is the fact that the settings are very limited. There are two settings. First setting is for two stroke, single cylinder, and four stroke two cylinder. Second setting us two stroke, two cylinder, and four stroke, four cylinder. That is all. You’ll be ok with two stroke settings, because most are single cylinder, but there are no four stroke settings for single, six, or eight cylinder settings.