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Post by chainsawwhisperer on Jan 22, 2010 6:44:33 GMT -5
I was just looking through an IPL for a 250.
I found a part that has me confused, It's the Tachometer - vibration arm p#68113. Does anyone know what that is for?
I would imagine it's for some type of governor, but there is no other parts listed, and I can not make sense of the IPL pic.
Thanks
Jim
P.S. I do not need this part, & I don't own a 250, I'm just curious.
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Post by lesorubcheek on Jan 22, 2010 7:56:28 GMT -5
Jim.... that's a good question. Found the part you're referring too in the IPL attached inside the air filter. Makes no sense at all to me. Can't tell how it attaches to the carb or anything else for that matter. No EZ-250s here, so sorry, but I'm of no help.
Dan
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Post by chainsawwhisperer on Jan 22, 2010 8:57:44 GMT -5
Thanks for looking Dan. Hopefully Craig will chime in with some help!
Jim
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Post by MCS on Jan 22, 2010 10:20:26 GMT -5
Homelite must have hired an engineer straight out of grad school and he needed something to do. The 250 has the auto chain adjuster and now this cute little piece of wire has been discovered. It is not mentioned in the shop manuals but looking at where it is mounted, on the air cleaner cover, and the fact that it isn't connected to anything tells me it is just what its name implies - it is a tachometer. Anyone have an owners manual for the 250? When I was in 10 grade shop I and a friend of mine each built a motor scooter. He had a 6 HP Power Products 2 cycle for his. His Dad helped him tune it one day and he had a vibrating tachometer. This tach was nothing but a sliding wire mounted on a plate with some numbers. The tachometer was rested on the engine frame and the wire was moved in or out until the wire vibrated widely. You would look at the plate and read the number - the RPMs. I suspect this piece of wire mounted in the air cleaner is visible at the top edge but the procedure to use it may be a little fuzzy. Here is what we're talking about - Item # 6 is mounted on item # 5.  |
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Post by sugarcreeksaws on Jan 22, 2010 11:12:05 GMT -5
Well, There is always something to learn about these darn things. I pulled my EZ-250 out and pulled off the cover,....sure enough there was the spring tucked in along the side. I put the cover back on and played with it a little,...as near as I can tell, when you are tuning the saw, you would swing it 90 degrees so that it is sticking out to the side above the muffler,...it can be done without taking the cover off. Optimal tuning then would have something to do with the wire and its vibration.    Can anyone produce a document on how to effectively use a simple device like this? Talk to you soon! Joe |
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Post by chainsawwhisperer on Jan 22, 2010 15:34:23 GMT -5
Wow! a built in tach, that is awesome!!! (in theory only)
Even as a gimmick, I'll bet it sold the saw to some people.
I figured that it was for some type of RPM limiting Governor.
Now I want one! ;D
Thanks Craig & Joe!
Jim
P.S. My next post will be #1000, I'm going to wait until I have something important to ask or say!
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Post by MCS on Jan 22, 2010 16:13:13 GMT -5
P.S. My next post will be #1000, I'm going to wait until I have something important to ask or say!  <MCS Gee, I wonder how long we will have to wait ;D |
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Post by 5runners on Jan 22, 2010 17:21:55 GMT -5
I seem to remember a tach used for R/C gas airplane engines called a Vibra-Tach.
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Post by MCS on Feb 17, 2010 21:32:47 GMT -5
Wow! a built in tach, that is awesome!!! (in theory only) Even as a gimmick, I'll bet it sold the saw to some people. I figured that it was for some type of RPM limiting Governor. Now I want one! ;D Thanks Craig & Joe! Jim P.S. My next post will be #1000, I'm going to wait until I have something important to ask or say! Awhile back Jim added this comment at the end of a posting. Well the time came and he found something important to say and finally crossed the big 1000 posts on HoH. Congratulation Jim. Craig |
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Post by Supercharged86 on Apr 6, 2014 21:09:45 GMT -5
I know this is an old thread but the question seems to have gone unanswered. As it would be, my recently acquired EZ-250 thankfully had the original air filter cover installed and with it the "Tachometer Vibration Arm", COOL! So after deploying the little mystery wire I fired up the saw. My guess is that it's used for setting the proper low speed rpm. As the saw sat there and idled the little wire with a coiled up end "waved" back and forth, like a metronome on steroids. It was mesmerizing to watch. As soon as you gave it a little throttle, it instantly stopped waving. So the question still remains, was it used for idle rpm setting? I'm gonna have to play around with it some more and compare it to my digital tach that I use for carb tuning. Cheers. Steve
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Post by sweepleader on Apr 7, 2014 11:54:54 GMT -5
I have seen cycle per second or Hz as in (60 cycle alternating current on standard electrical lines) meters that consist of about 5 reeds similar to the wire. The reeds would stop vibrating when the cycle rate on the electrical line matched the rate the reed was tuned for. The center reed of the group was for 60 Hz. These things were sometimes mounted on generator sets to get the speed correct. I am sure Steve is on the right track, just need to figure out what speed the engineers wanted it to be used for. It might in fact work at a couple of different speeds, harmonics. Let us know what you find out.  Dan |
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