Adjusting rpms- Kohler 8hp K241s engine

[Joe 77 B100 84]

Hey there folks.  I got my 77 B100 running but I had to adjust a lot to get to that point.  I think I got the carb back together well but I DID have to adjust the governor arm and the wire from the lever on the dash.  When full throttle, the engine doesn't really sound like its in full throttle and the snowblower was definitely "weak" when I tests it out.

I think I need to adjust the governor and get it to work at a higher rpm.  But, someone said to make sure I don't just do it and end up burning up the engine.

1) How does one know that the engine throttle settings/governor are set right and

2) Can someone send me to a thread with pics or a video or, better yet, to a YouTube video that shows me how to make sure I have it set right and/or adjust it?

 

I can send a video of it on full and low throttle but maybe you cannot know it is set right just by sound. 

 

Thanks in advance for your help.

[oliver2-44 10,785]

Do you have access to any sort of RPM measuring device? 

When you say you adjusted the governor arm, do you mean the adjustable rod between the governor and carb, or the governor itself? 

Since getting a tach, I feel more confident doing tuning and Governor setting.  Just setting by ear, my engines were all running slow on the lower end (1250) and the upper end  (3600)

Here's some Tach reference material.

https://www.mechanicwiz.com/small-engine-tachometers/  If you get something like this make sure it has a replaceable battery, looks like most of them do now.  Several years ago I bought one of them an battery was not replaceable, so it was trash in a year.

 https://www.amazon.com/gp/product/B07DZB57H5/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=mechanicw-20&creative=9325&linkCode=as2&creativeASIN=B07DZB57H5&linkId=6cd6ea5b3598026c50dffc8189f4e501

 

https://housetechlab.com/how-to-measure-engine-rpm-with-a-multimeter/

 

https://www.fullyinstrumented.com/best-tachometer/

https://www.fullyinstrumented.com/best-tachometer/  I have the Neiko 20713A Lazer Non Contact Digal tachometer $24.  You put a little piece of reflective tape on the shaft or flywneel for the lazer to read and it works good

 

[rmaynard 16,386]

Before doing anything, use the static timing method to be sure you have the correct timing. Use this link: https://mgonitzke.net/cubcadet.html Click on HowTo and download the pdf file.

 

Follow the instructions in the Kohler manual to the letter when adjusting the governor.

 

Tune the carburetor as the Kohler manual says. However, I am the type of guy who starts with the basic Kohler info, then I tune by ear. In other words, even it might not be exactly by the book, if it sounds good, it usually is. 

 

Checking RPM is a simple as buying a $20.00 laser tachometer from Amazon. It was only $8.00 when I got one in 2011. That's inflation for you. https://www.amazon.com/gp/product/B001N4QY66

 

 

 

 

[Jeff-C175 7,206]

The laser tach I recently bought isn't great.  I found that I had to aim it at a 45 angle to get it to read 'correctly'.  Or at least what I think is correct... because at this point I'm not confident in it's reading.

 

I wonder if there's a tach app for phone?

Edited January 12, 2022 by Jeff-C175

[pfrederi 18,724]

2 minutes ago, Jeff-C175 said:

The laser tach I recently bought isn't great.  I found that I had to aim it at a 45 angle to get it to read 'correctly'.  Or at least what I think is correct... because at this point I'm not confident in it's reading.

  Better than doing it by"Ear"

[Jeff-C175 7,206]

Just now, pfrederi said:

  Better than doing it by"Ear"

 

Yes it is, but one second this thing says 30,000 then 18,000 then 20,000 then 75 then... So how can I feel comfortable that ANY reading is correct?

 

It does seem stable when turned at a 45 angle though, and 'sanity check' of 3550 at top throttle is 'probably' correct.  Maybe...

[rmaynard 16,386]

12 minutes ago, Jeff-C175 said:

 

Yes it is, but one second this thing says 30,000 then 18,000 then 20,000 then 75 then... So how can I feel comfortable that ANY reading is correct?

 

It does seem stable when turned at a 45 angle though, and 'sanity check' of 3550 at top throttle is 'probably' correct.  Maybe...

Funny how things work. That little gadget that I bought for $8.00 way back then, was extremely accurate. You got a bunch of little reflective dots to put on the flywheel or the grass screen. They would always give you a nice "spot" to test. I have a buddy who is always ragging me about my "cheap" toys. He brought over his mega dollar tach that he uses for work. Comparing the two, the RPM's were identical.

 

23 minutes ago, pfrederi said:

  Better than doing it by"Ear"

Paul, just to clarify, I tune the carburetor by ear, not the timing. 

[Jeff-C175 7,206]

29 minutes ago, rmaynard said:

You got a bunch of little reflective dots to put on the flywheel or the grass screen

 

Yup.  If you put on more than one you would have to divide by the number of dots.  I think that would give better accuracy for slow turning things.

 

I believe that the problem with this is that it's TOO sensitive and is reacting to the holes in the grass screen since I've painted that a nice shiny red!  No way can I count all the holes in Albert Hall!

 

So I ran a stripe of black electrical tape around the perimeter and that helped some, but was still a bit too shiny and still gave false readings.

 

I'm reasonably confident that turning it to point at 45 degrees is accurate... but you know what they say about the guy with two wrist watches... he's never 100% sure what time it is!

 

At some point I'm going to get a piece of flat black cardboard with one shiny spot and tape that to the grass screen to see if that gives a stable reading.

 

By the way... I noticed that if I point it at my fiberglass welding blanket, the blanket is also turning at a very high RPM!

 

In retrospect, I believe I would have been happier with one of the inductive models that you wrap the lead around the spark plug wire.  I'm sure that those would give a less ambiguous display of RPM.

 

Edited January 12, 2022 by Jeff-C175

[RED-Z06 2,601]

After 18 years of working on them my internal tach is +/- 50rpm🤣

[WHX?? 51,931]

 

1 hour ago, rmaynard said:

$20.00 laser tachometer from Amazon.

I been eyeballing that one Bob ... The one I got is a piece of crapadoodle. Gonna pull the trigger you say it's good enough for a backward hammer mechanic. 

 

Guessing you have a manual Joe? If not we can get you one the procedure for adjusting the guv arm is in there. 

Also if your motor has the thing circled in this pic it is the rev limiter It should be adjust upward so the bellcrank arm hits it at full throttle  at 3600 RPM. . Its way off in this pic. 

Some pics of how your linkage is set up would help us help you alot. 

[WHX?? 51,931]

2 hours ago, Jeff-C175 said:

 

I wonder if there's a tach app for phone?

 

Not to hijack your thread Joe but yer a regular rocket scientist today Jeff  don't know why I didn't think of this.

 

Mr.  has alot of them for android but my phone is such a piece of crapadoodle too and they probably won't work on it. 

 

https://play.google.com/store/apps/collection/cluster?clp=ggEMCgp0YWNob21ldGVy:S:ANO1ljI7yCA&gsr=Cg-CAQwKCnRhY2hvbWV0ZXI%3D:S:ANO1ljKpxzU

[Handy Don 14,158]

2 hours ago, Jeff-C175 said:

The laser tach I recently bought isn't great.  I found that I had to aim it at a 45 angle to get it to read 'correctly'.  Or at least what I think is correct... because at this point I'm not confident in it's reading.

 

I wonder if there's a tach app for phone?

I've had good luck with the iOS app "video tachometer" using only a piece of white tape on the PTO pulley. It works by synchronizing the LED light as a flash with the shutter speed of the camera.

 

Warning: with this app you set your "target" or "estimate" RPM and then adjust the engine toward that number by watching the screen until the pulley "stands still" in the on-screen video. It is not a simple "how fast is this turning" sort of tool. It is possible to change the target quickly in increments of 10, 100, and 1000 RPM to "hone in" on a speed. A number of advanced features are in the "pay" version, but I've never used them.

 

I use it by setting it for 1000 RPM to set idle and 3400 for full and then adjusting the engine as needed. I also have learned to use a tripod and clamp to hold the phone pointed at the pulley while I futz with the engine!

Edited January 12, 2022 by Handy Don

[clueless 3,275]

Your B100 K241 is a 10 hp not an 8 just make sure when setting the gov your looking at a K241 not a K181. It could be a little confusing.

 

 

[gwest_ca-(File Mod) 11,539]

Have an electric motor in the workshop that drives a pulley? Induction motors are very accurate and a good place to test a photo tach.

[Wheelhorse#1 1,830]

I’d like to put one of those “Dots” on my mother in laws jaw just too see how fast it goes .

[Jeff-C175 7,206]

3 hours ago, WHX?? said:

alot of them for android

 

The several I just looked at all appeared to be 'strobe' tachs that use the phone's flash(light) .  I think you have to manually change the speed until you 'stop' the motion and then read the speed.

 

There ought to be a way for a slick developer to use the phones camera, maybe there is one, I'll keep looking.

 

[Joe 77 B100 84]

23 hours ago, oliver2-44 said:

Do you have access to any sort of RPM measuring device? 

When you say you adjusted the governor arm, do you mean the adjustable rod between the governor and carb, or the governor itself? 

Since getting a tach, I feel more confident doing tuning and Governor setting.  Just setting by ear, my engines were all running slow on the lower end (1250) and the upper end  (3600)

Here's some Tach reference material.

https://www.mechanicwiz.com/small-engine-tachometers/  If you get something like this make sure it has a replaceable battery, looks like most of them do now.  Several years ago I bought one of them an battery was not replaceable, so it was trash in a year.

 https://www.amazon.com/gp/product/B07DZB57H5/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=mechanicw-20&creative=9325&linkCode=as2&creativeASIN=B07DZB57H5&linkId=6cd6ea5b3598026c50dffc8189f4e501

 

https://housetechlab.com/how-to-measure-engine-rpm-with-a-multimeter/

 

https://www.fullyinstrumented.com/best-tachometer/

https://www.fullyinstrumented.com/best-tachometer/  I have the Neiko 20713A Lazer Non Contact Digal tachometer $24.  You put a little piece of reflective tape on the shaft or flywneel for the lazer to read and it works good

 

You got to me first so I am starting with your email.  I did some research so I can use more detailed explanations.

I adjusted setting of the governor lever on the cross shaft by loosening the bolt, pulling the lever to the right as you sit on the mower, turning the shaft all the way counterclockwise and then tightening the bolt again.

But, I had to release tension on the line/wire from the dash controls to the governor so those might be set wrong when I reattached them as I have not read anything about the settings there yet.

I will look into your suggested purchases and read the rest of the posts.  There are a LOT of them- which is freaking awesome!

[Jeff-C175 7,206]

53 minutes ago, Joe 77 B100 said:

setting of the governor lever

 

...sounds correct.

 

Which holes is the governor spring in?

 

@WHX?? posted a pic of the top end limit, is yours in a similar position?  That one is a bit on the lower [edit:] HIGHER speed side,  further counterclockwise would be more normal.

Edited January 13, 2022 by Jeff-C175

[Joe 77 B100 84]

22 hours ago, Jeff-C175 said:

The laser tach I recently bought isn't great.  I found that I had to aim it at a 45 angle to get it to read 'correctly'.  Or at least what I think is correct... because at this point I'm not confident in it's reading.

 

I wonder if there's a tach app for phone?

If there isn't, that is a million dollar idea.  I will check.  And, hey, do you have any banjo music posted anywhere? I'd be interested in checking it out.

[Joe 77 B100 84]

22 hours ago, Jeff-C175 said:

In retrospect, I believe I would have been happier with one of the inductive models that you wrap the lead around the spark plug wire.  I'm sure that those would give a less ambiguous display of RPM.

 

It seems to my mind, that WOULD be the most accurate?  What are they called and I will look into that option.  I also have a friend who is an auto mechanic who always seems to have an opinion about the "best" way to do something- in his experience. 

[Jeff-C175 7,206]

2 minutes ago, Joe 77 B100 said:

banjo music posted anywhere?

 

I think there is some on Youtube, but I'll have to dig to find it.

 

I've got some MP3 files I could send if you PM an email address I could send to.  

 

[Joe 77 B100 84]

20 hours ago, WHX?? said:

 

Not to hijack your thread Joe but yer a regular rocket scientist today Jeff  don't know why I didn't think of this.

 

Mr.  has alot of them for android but my phone is such a piece of crapadoodle too and they probably won't work on it. 

 

https://play.google.com/store/apps/collection/cluster?clp=ggEMCgp0YWNob21ldGVy:S:ANO1ljI7yCA&gsr=Cg-CAQwKCnRhY2hvbWV0ZXI%3D:S:ANO1ljKpxzU

I'm for sure gonna start there, take some pics for you guys, see if I can upload a video of it running and get back to you. 

I don't like puzzles or any video games but this whole "can you figure out what is wrong and fix it" thing is quite enjoyable.  I wish I'd had a Dad that got me into this when I was younger.

[Joe 77 B100 84]

19 hours ago, clueless said:

Your B100 K241 is a 10 hp not an 8 just make sure when setting the gov your looking at a K241 not a K181. It could be a little confusing.

 

Ugh.  Yeah, I knew that. 

[Jeff-C175 7,206]

6 minutes ago, Joe 77 B100 said:

What are they called

 

Search Amazon for "small engine tachometer" and you'll get lots of hits.  Both LED and inductive.  All around $25 or so.

[Joe 77 B100 84]

18 minutes ago, Jeff-C175 said:

Which holes is the governor spring in?

 

@WHX?? posted a pic of the top end limit, is yours in a similar position?  That one is a bit on the lower speed side,  further counterclockwise would be more normal.

Yeah.  When I pulled off some of the items to get to the carb, I didn't take pictures to be sure where it was- but I am not even sure the PO had it in the right hole.  If there is a "right" hole, why are there the 5 or 6 in the arm? 

I will take pics and post them for you folks later after I get some work done today.