Flywheel gear

[roy697]

Does any one know how many teeth are on the SL3105BT, FT404, 3 cylinder? The tach on my tractor is shot & I need a workaround, cost of a new one is over $200. Don't need one that bad. Any thoughts?

[quicksandfarmer]

Harbor Freight and Northern Tool both sell add-on tachometers.

Are you sure the problem iw with the tach? usually the problem is the sensor.

[GuglioLS]

Roy,

I don't know exactly how many flywheel teeth Franky has but my Goldie (Jinma 354 3 cylinder) has 117 flywheel teeth. I counted them one at a time a long time ago to measure the accuracy of the tach. Turns out the tach was dead on.

Is the tach meter bad or the sending unit on the flywheel? Do you have access to an oscilloscope? If so are you thinking about measuring the timing of the pulses coming from the tach pickup? That's how I measured and calculated the actual RPM's to compare to the tach readout.

Most likely you're running your tractor based on engine sound and workload which usually works just fine.

My Dozer never had a tach and I get along just fine without it.

There are aftermarket tachometers for diesels but they can get a little pricey. Somewhere I think I saw a hand held tach gun. You put a piece of reflective tape on a rotating shaft and point and shoot for a direct read out.


Larry

[Rich Waugh]

These are only $95:

www.tinytach.com/tinytach/diesel.php

Rich

[roy697]

I checked with Harbor Freight, there tachometers were all for gas engines.
My tachometer is dead.







Franky had two trees fall on him & broke just about everything that trees could break, the fiberglass dash was smashed but the instrument cluster seemed to be OK, only thing that is not working is the tach. When I was taking things apart after I bought Franky I disassembled the instrument cluster & water had been setting in the tach, parts rusted & fell off the board & was laying on the bottom, I have not checked the sensor. With the 2 speed pto I was looking for ways to be more frugal, run the pto at 1000 rpm mode & cut the engine speed down & save on fuel. I am focusing on putting up a building on the farm but if I can make shift a tach for Franky kind of cheap I will give it a try. I don't expect to spend a $100 on that project, I have way to many higher things that I need first. Driveway to the barn, dozer work, stone for the driveway. Any how I found a tach on ebay that I may take a gamble on.

Some of you guys have a lot of knowledge about stuff so if any one knows the ins & outs of these please post.
Thanks for all the input.

[GuglioLS]

No doubt that's seen better days.

Hey Rich, that's a cool unit. I did some searching and came up with the same unit you did.

It's a $95 add-on tach and hour meter for diesel engines. It clamps onto one of the high pressure fuel injection lines and counts the pulses going to the injector. It also acts as a multifunction hour meter so it solves both problems. No guessing when to perform service at the correct hourly intervals. I might pick one up for the Dozer, it would be kind of nice to know the RPM's.

www.tinytach.com/tinytach/diesel.php

Install instructions:
www.tinytach.com/tinytach/installation_diesel.html


Operating Instructions:

www.tinytach.com/tinytach/operating_diesel.html

Larry

[Rich Waugh]

Sometimes even not-so-great minds think alike, huh? :-) :-) :-)

Rich

[GuglioLS]

Roy,

I picked up one of those Tiny Tach's that Rich provided a link to and installed it on my Dozer. Before doing that I did some testing on my Jinma to see how well the Jinma and Tiny tach correlated. See the results below.....




No doubt I was impressed, both the tiny tach and the accuracy of the Jinma tach, exceeded my expectations. It's more than just a tach and hour meter, it's got 2 service reminders, a job timer as well as a max RPM indicator. I can recommend it - 5 stars in my book.

Larry

[Rich Waugh]

Thanks for the field testing. Larry! I was pretty intrigued by it when I did the search and put i ton my "someday" list. Now I may up the priority level a little on that one - that's just too cool for words for under a hundred bucks. The service reminders alone are worth the price of admission, at least for me. I have and hour meter on my lawn tractor that tells me it's time to change the oil and I find it really helps to get me to actually do it in a timely fashion instead of procrastinating. And I've never trusted the Jinma hour meter on job times - I use my watch and it and the tractor's hour meter don't agree by a fair margin sometimes. Since I bill a few people for tractor time by the hour I need an accurate log.

Now, what's the next goodie I might like to have but aren't sure about??? Maybe I can get Larry to test it for me... ;D

Great documentation, too!

Rich

[roy697]

Thanks for the info. That looks & sounds nice. It is on the back burner for now.
( I bought a hand held Tach for $12 that uses a light beam. I have not had the opportunity to get down the the farm & try it. Plan is to mark the throttle once I get the pto to speed, I am guessing that will be close enough for cutting that tall green stuff that comes up. )



I don't have a cab on Franky, is the Tinytach weather proof?

[GuglioLS]

Jul 13, 2010 0:12:28 GMT -5 @Ruchbah said:

Thanks for the field testing. Larry! I was pretty intrigued by it when I did the search and put i ton my "someday" list. Now I may up the priority level a little on that one - that's just too cool for words for under a hundred bucks. The service reminders alone are worth the price of admission, at least for me. I have and hour meter on my lawn tractor that tells me it's time to change the oil and I find it really helps to get me to actually do it in a timely fashion instead of procrastinating. And I've never trusted the Jinma hour meter on job times - I use my watch and it and the tractor's hour meter don't agree by a fair margin sometimes. Since I bill a few people for tractor time by the hour I need an accurate log.

Now, what's the next Gordie I might like to have but aren't sure about??? Maybe I can get Larry to test it for me... ;D

Great documentation, too!

Rich

No problemo there Rich "Now, what's the next Gordie I might like to have but aren't sure about??? Maybe I can get Larry to test it for me... ;D"

You bet, buy anything you like and have it shipped it to me first for testing / breaking(in) ;D



Roy - "I don't have a cab on Franky, is the Tinytach weather proof?"
It's hermetically sealed so yes it's weather proof. My dozer sets outside (for now) so this thing should last.

Larry

[3RRL]

Great field test Larry,
What I am impressed with is not so much the "Tiny Tach", but moreso with how your Jinma tach was accurate.
My Kama tach is not working all the time now. When I first start it ... nothing on the tach. Then sometime after it's been running a while, all at once the tach "pops" on and starts to work. I've tried to adjust the proximity to the flywheel by turning it in and out, but no luck with that. Before I consider buying that "Tiny Tach", is there something else I should adjust, or some electrical (egads) connection to check?
Like I said, it starts to work after the tractor's been running a while but never when I first start it. The only good thing is I've had so many hours on the Kama, I can tell by ear what rpm I'm achieving.
Rob-

[roy697]

When I was looking at the Tiny Tach at their web site I was wondering if it was weather proof so I sent them a email, their reply was:

All Tiny-Tachs are completely potted inside so there can be
no damage to the circuitry from moisture or vibration. The
Lexan label that covers the top is waterproof. If the tach will
receive extreme exposure to moisture, we suggest rubbing
a small bead of silicon around the outer edge of the top label
to prevent possible "fogging" -- like you might get with a
watch crystal. That would dry, but it might be hard to read
in the meantime.
Best regards,
Margie
DTi

[GuglioLS]

Jul 14, 2010 11:49:58 GMT -5 3RRL said:

......snip....snip....Before I consider buying that "Tiny Tach", is there something else I should adjust, or some electrical (egads) connection to check?
Rob-

Hey Rob,
Glad you noticed how accurate that Jinma tach is. I'm impressed too. On your Kama is it just the tach that's intermittent? Are the fuel and temp gauges dropping out as well? How about the hour meter, does it still clock hours when the tach is not reading RPM's? The answer to those questions will help determine exactly where to look. One thing certain about that "tiny tach" is you wont have to guess the real hours. I remember you saying the Kama hour meter was tied in with RPM's and did not record the real engine on time. The Tiny Tach records actual engine running time so no guessing when to perform maintenance.

I wonder if your flywheel sensor is going out? Try heating it up with a heat gun to see if it has any affect on it working as soon as you start the tractor. There is always the banging on it with a wrench to beat it into working as an option.

Larry

[3RRL]

Thanks for your response Larry ...
Your questions below:
-On your Kama is it just the tach that's intermittent?
The fuel gauge jumps around too, but the other gauges (water temp and voltmeter) work fine.
-Are the fuel and temp gauges dropping out as well?
No, they are OK
-How about the hour meter, does it still clock hours when the tach is not reading RPM's?
Yes it does, but according to my watch, it records less hours than actual. I usually work the tractor between 1500rpm to 1800rpm.

-I wonder if your flywheel sensor is going out? Try heating it up with a heat gun to see if it has any affect on it working as soon as you start the tractor. There is always the banging on it with a wrench to beat it into working as an option.
I will try that later this week.
Thanks again Larry.
Rob-