Installing Balance Gears

[Dave M 0]

Has anybody had to reinstall the balance gears in an engine rebuild? I was having what I thought were governor problems (engine running at high RPM's ungoverned) so I tore this 16 HP Magnum down to the governor (just about the last thing to remove). I marked where the gears (crank, cam, and lower balance gears) mesh, but I missed marking the upper balance gear. The book says you need a special tool to synchronize the balance gears with the crank. Secondarily, if you don't have the balance gear tool, it says to use the timing marks on the gears/crank/camshaft. Has anybody successfully reinstalled these gears using only the timing marks? Any tricks to the procedure? BTW, I got the governor mechanism out and it looks good and intact. I think I may have torn into this motor for naught. Any ideas as to why I am having the high rpm problems? In the teardown, it seemed like the carb to block mounting bolts weren't real tight and the fuel pump mounting screws to block were not tight either. It's hard for me to imagine that either one of these issues were causing the over rev problems. Thanks, and, my first post on Red Square.

[WH nut 553]

I have always used the marks on the gears and never had a problem

[TT-(Moderator) 1,127]

:thumbs:

I always throw the DCB gears in the garbage.

It beats having a block with a big hole in the side. :notworthy:

[gregg.d250 0]

There is a throttle stop on the pivot tab where the throttle cable is linked to the governor arm spring. This pivot tab will have multiple calibration holes where the bellcrank spring can be inserted to adjust sensitivity. If the limiting tab sharing the common bolt is not set to limit the upper RPM ceiling, the engine will rev unrestrained.

The governor is designed to open the throttle under load, and close the throttle when the load is relieved for a given throttle setting. It will not control the top RPM the engine can achieve. Only the throttle stop limits this.

Using a tachometer, set your unloaded RPM ceiling to 3400-3600 RPM by loosening the fixing bolt and using the throttle stop tab to hold the RPMs under the design limit. If using a 4-cylinder tachometer, multiply the reading by 4 to get the true RPM. Connect the tach input lead to the negative terminal on the coil.

To reset the governor, loosen the bellcrank clamping bolt, use vise grips to rotate the governor shaft clockwise, while pulling the bellcrank forward, opening the throttle. Hold and tighten the bellcrank clamp bolt. You have now reset the governor to factory positioning.

If the engine does not respond well to changing loads, the spring can be inserted in different bellcrank and pivot tab holes to adjust the sensitivity. That's a whole writeup in itself to do that calibration.

[Dave M 0]

I appreciate the feedback. TT, are you serious about pitching the balance gears? If they don't serve a purpose, why are they in there? And Gregg250, I attempted to set the governor in the manner you suggested per the Magnum manual but it didn't help the high revs. I did this at least a year ago, long before I felt like the problem had to be internal. I have not, as I recall tried to set the sensitiviy via the spring. I also do not have a tach. I'm not sure if I follow your description of the "limiting tab sharing the common bolt" description you use. I also have a 310-8 (Magnum 10HP) that I can use for reference. I just rebuilt it, about a month ago, but didn't remove the crank or cam, so I wasn't into the governor area of that one. Thanks again for the input.

[baerpath 517]

Yup TT's serious

We also throw the balance grenades out.

[tranders 0]

I thought the governor shaft was to be turned counter clockwise.

[gregg.d250 0]

I stand corrected- CCW is the proper direction-

Attached Image (Click thumbnail to expand)

[gregg.d250 0]

Another

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[gregg.d250 0]

Instructions-

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[Dave M 0]

Balance grenades?? Now you're just messin' with me. As for the the gov adjustment, I did that when the rev problems first occured. When it didn't rectify the issue, I thought there were internal problems.

[Electro12WH 50]

Some K-series engines came from the factory without the gears. They smooth out the vibration a little bit, but it's fine without them. They're not worth the hassle if you want to leave them out.

[gregg.d250 0]

Balance grenades?? Now you're just messin' with me.

Some of the earlier designs for the balance gears had problems and they'd suffer brittle fracture and 'explode' within the engine.

There's an endless debate over their effectiveness and whether or not to use them, but on a 16-Hp - you've got a lot of reciprocating mass with a 3.75" diameter piston and they make some kind of difference.

I think pulling them out of a K241 or K301 might not be noticeable, but with the 14 and 16-Hp engines, you're throwing around a lot more weight with the larger piston (stroke is same for 12/14/16-Hp) and physics is physics. Can't overcome that. I believe they make a bigger difference in smoothing out the primary horizontal rotating couple and vertical shake in the larger displacement engines.

FWIW - I always put them back in, and I use the newer-design version when doing a rebuild of an older K-series. A Magnum version definitely has the newer design.

I'm just an engineer..... what do I know??? =)

[rickv1957 70]

I have rebuilt lots of Kohlers over the years and done them both ways gears in,gears out,never could tell any differance, Rick

[gregg.d250 0]

Here's the diagram with the high-speed limiting tab illustrated so you can see what I'm referring to-

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[Dave M 0]

Okay then, thanks for the balance gear debate. I expect I'll leave them in unless it becomes too much of a PIA to do so. Your last illustration with the high speed limiting tab clears-up a whole world of questions. I appreciate all of the input and responses to my questions. Dave

[TT-(Moderator) 1,127]

In case you want more reading material:

Previous balance gear post link.

[Sarge 3,462]

I had the same issue with 4 of my WH's , all of them were missing that stupid tab for whatever reason. Cannot figure out why someone would even take it off....?

As a plus, I can make a new one now in about 2 minutes...lol .

Sarge

[Jim_M 178]

I generally find the engine is quieter without the gears. I don't trust the gears anymore, I lost a perfectly good K141 block a few years ago because the gears broke and knocked a hole through the block.