balance gears (?)

[kudzu3 323]

I saw on another thread, concerning a 341 rebuild, some advised to remove the balance gears. Rather than hi-jac that thread, I thought it better to start my own. I'm in the process of a 301 rebuild, would this advice apply to mine also? I don't know which gears are the balance gears, so a little more elaboration would certainly be appreciated. A picture would be nice, Thanks

Edited September 6, 2015 by kudzu3

[MalMac 1,332]

The balance gears are the two smaller half moon gears that are on two separate studs. On the k301 you can take them out. The old K series are better off without them. There is s reason they call them grenade gears. When they or their bearings wear, they find ways to make a exit out of the motor. Usually by creating there exit hole.

[Horse46 519]

Are they not part of the main gear, mine look as though they are?

 

 

 

Edited September 7, 2015 by Horse46

[MalMac 1,332]

No, they are in there on two different stubs. They are held on by snap rings. 

[Horse46 519]

OK I'm with you now, each one is a whole and two halves, I thought the two half gears were the balance gears.
In the picture is 1 balance gear right?

[kudzu3 323]

If I remove them will I feel more vibration from the running engine? Isn't the job of these to make the engine run smoother? Looking at them, seems to me that they would cause more vibration than less. Oh well, guess that's why I'm not an engineer .

[JAinVA 4,638]

Kudzu,
    I asked pretty much the same question a few months back.I had found that in the K series some users did not have the balance gears from Kohler.As I understood it the gears were an option from Kohler.I was told that leaving them out would not hurt a thing.I just rebuilt a K301 and found no difference in vibration by leaving the gears out.This again was in a K series,the answer may be different in the Magnum series.Hope this helps,JAinVA

[kudzu3 323]

Okay, one more question. Advice has been given to have the engine balanced, piston, rod and crank. No one in my area can do this, some don't even know what I'm talking about when I ask. My rebuild is too far along to have this done, but I am curious about this procedure. Can someone explain how this would be done, and what the advantages would be? As I said, just very curious. Thanks 

[gregg'shorses 77]

Balancing the engine would be need to get high rev's, not stock less than 3600 rpm. Balance gears in or out are a personal preference. Last engine I did a K341 16hp , I put them in. They have to be timed when installed one at a time. The manual goes in detail how to do it without special tools..... But some " colorful " language won't hurt.

[eddiebunyan 24]

I wouldn't delete the balance gears personally,but I would reccomend getting the shim clearances as close as possible(kohler makes a shim kit for these). Most people probably skip this step and gear failure could be the result.

[Fordiesel69 271]

In addition is you have the "new style" gear without the slots like the ones in the magnums, I have not heard of these failing. 

Also one complete engine life without a rebuild??????  I don't think they would fail.  Get one or two rebuilds on them and bam.  Conversly, why was the engine rebuilt, let me guess, lack of oil changes or lack of oil right?

[Horse46 519]

My crank measured 010 under so I'm gussing it has had a rebuild at some time? My balance gears are going in........in the bin!

[eddiebunyan 24]

Again Fordiesel,If the balance gears are not shimmed to specs at the rebuild they won't run true,wear unevenly and eventually fail!Not the fault of the gears. I wonder what the tech's at Kohler would say about leaving the gears out?? Horse46 was your piston oversize,also indicative of a rebuild?. If the crank was worn that much shurly the bore would have been at least .010 out? Just curious.

[Shynon 7,482]

Standard bore, standard crank as built by Kohler.
 

[WNYPCRepair 1,923]

Given the possibility of the balance gears making their own exit hole, and that they don't seem to reduce vibration, I know I will leave them out if I ever do a rebuild. Regardless of why they fail, with no clear benefit, it just seems like a risk I would rather not take
 

[Horse46 519]

Again Fordiesel,If the balance gears are not shimmed to specs at the rebuild they won't run true,wear unevenly and eventually fail!Not the fault of the gears. I wonder what the tech's at Kohler would say about leaving the gears out?? Horse46 was your piston oversize,also indicative of a rebuild?. If the crank was worn that much shurly the bore would have been at least .010 out? Just curious.

I would imagine that the crank would have been ground to that spec because of wear, not from wear.

[Horse46 519]

Again Fordiesel,If the balance gears are not shimmed to specs at the rebuild they won't run true,wear unevenly and eventually fail!Not the fault of the gears. I wonder what the tech's at Kohler would say about leaving the gears out?? Horse46 was your piston oversize,also indicative of a rebuild?. If the crank was worn that much shurly the bore would have been at least .010 out? Just curious.

I would imagine that the crank would have been ground to that spec because of wear, not from wear.

Talking of the balance gears, you say shimmed to spec? My balance gears move side to side by about 4mm, they have shims either side, that are around 1/2 mm. Am I missing something here, or are they not supposed to move side to side?

[eddiebunyan 24]

Then perhaps someone did a rebuild and found that the bore measured under.010 wear but the crank was worn more then specs and had it turned to accept a .010 under rod. Or maybe the bore was out,didn't want to replace the piston and rings and left it to move causing excessive wear on the crank journal? That's why I asked if you measured the bore.  The "Kohler single cylinder engine service manual" page 12-3  says "recomended end play is .002/.010. (Kohler part# 47 755 01. So if 1MM=0.03937 then four times that would be 0.15745  and yes according to"Kohler" they would be out of tolerance!I know I'm being picky(probably not the word you would use) but the tolerances are there for a reason.

[Don1977 605]

There can also be wear on the balance gear shafts and the roller bearings that would cause more problems then side play.

[kudzu3 323]

Finally got my engine ready to start assembly, carried it to my friend and small engine builder to install the piston, rod, crank and valves. I asked him about the balance gears. He also advised leaving them out. He said that I could tell no difference, and (as most have said) they could cause big problems. This has been a valuable learning experience for me and I thank you all for your input.