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View Full Version : "Souped Up" Kohler 27hp ??


cajuncreole
02-28-2008, 04:54 AM
I have an Exmark 66" 27hp Kohler. I mow in South Louisiana and have quite a few old pastures to keep up 5-10 acres. They are in Bahaia some on former garden plots, so the grass is very thick.

I mow most once a week, but some every other week and during the spring on certain very thick parts of the plots with the throttle wide open, the Kohler 'boggs down" and I have to crawl through the area, to keep from stalling the engine out.

I went to the mechanic at the dealer, he is a very competent mechanic, and he said he would "advance the spring setting on the governor" and I should be able to get through this heavy grass without slowing down as much.

He said he would install a tach on the mower and I should never go over Kohlers recommended top end of 3600 RPM's.

I sharpen the blades daily, clean the deck daily and spray it with lube to keep grass from building up. I run synthetic oil and change filters as needed. Any thoughts??

Thanks,
Louis

topsites
02-28-2008, 05:03 AM
All depends how long you been doing this, I think.

Because I did that for a while, until I got tired of it.

Now I do all that and run a namebrand premium unleaded, plus autolite double platinum plugs (keep in mind they need replacing every 2 seasons vs. every 1 for standard), autolite.com offers a cross-reference thing on their site.

But once it gets to a point my machine starts to bog down anyhow we have a problem, because it shouldn't.
Yes sir, sharp blades daily and a clean pre-cleaner and all that crap, come on now.
So either I can come by more often, I can charge extra, or my best solution yet is I start to raise the cut height.

This works for most, most of the time.

But one way or another, push comes to shove like I show up and I can see it needs it now and the customer comes running out talk about wait another 3 days (or better yet another week)? No problem, I get back in my truck, and leave. When they call wondering where I am, I'll be there tomorrow.

Richard Martin
02-28-2008, 06:11 AM
I don't recommend adjust the governor spring. If it's weak and needs to be replaced then fine, replace it. Otherwise leave it alone. The governor spring is set to control engine RPM. It is also set to control surging too which is usually the result when you try to adjust it.

Unfortunately 27 HP is 27 HP and there is no quick or safe way to increase it. Your only recourse is to cut it more often or raise the height of cut.

You can also raise the RPM to 3750 but watch for increased oil consumption.

MarcSmith
02-28-2008, 07:45 AM
gotta remember the mower is a finish mower, and not a bush hog.... you either have to cut more frequently or cut higher . The only other thing you could possibly do would be to "re pully" the spindles, to get a higher blade tip speed, or put on a heavier blade that way once the heavier mass gets spinning its harder to slow down...

you you do a double cut, cut it once high, and then drop it down for the second cut....but then they better be paying for the double cut.

cajuncreole
02-28-2008, 11:41 PM
Thanks guys, so to maximize engine efficiency horse power:
1) Sharpen blades daily.
2) Clean deck underside daily.
3) Spray deck underside with lube.
4) Premium gas.
5) Premium plugs.
6) Synthetic oil.
7) Clean filters.
8) Repulley spindles for higher Blade Tip Speed.
9) Advance governor for higher RPM's to 3750.

Anyother tips on what works for you. I have to get the most out of what I have.
Thanks.

tb8100
02-28-2008, 11:42 PM
Air precleaner and filterminder gauge to monitor restriction.

puppypaws
02-29-2008, 01:02 AM
I have an Exmark 66" 27hp Kohler. I mow in South Louisiana and have quite a few old pastures to keep up 5-10 acres. They are in Bahaia some on former garden plots, so the grass is very thick.

I mow most once a week, but some every other week and during the spring on certain very thick parts of the plots with the throttle wide open, the Kohler 'boggs down" and I have to crawl through the area, to keep from stalling the engine out.

I went to the mechanic at the dealer, he is a very competent mechanic, and he said he would "advance the spring setting on the governor" and I should be able to get through this heavy grass without slowing down as much.

He said he would install a tach on the mower and I should never go over Kohlers recommended top end of 3600 RPM's.

I sharpen the blades daily, clean the deck daily and spray it with lube to keep grass from building up. I run synthetic oil and change filters as needed. Any thoughts??

Thanks,
Louis

Mistake.... Kohler's recommended rpm's on the 27 hp is 3750.... some use more oil, some don't!

Richard Martin
02-29-2008, 06:10 AM
8) Repulley spindles for higher Blade Tip Speed.


I don't like this one. Although you can increase the BTS this way it also decreases the torque going to the blades. Torque is twisting force. If you hit a heavy patch of grass the engine will have to work harder and will probably loose RPM faster. Just increase the engine RPM as this will increase BTS anyway. You do not have to touch the governor or the spring to do this. There is a simple adjustment bolt on the throttle linkage designed just for adjusting the top end RPM. You may need to also adjust the throttle cable too.

delphied
02-29-2008, 09:27 AM
Thanks guys, so to maximize engine efficiency horse power:
1) Sharpen blades daily.
2) Clean deck underside daily.
3) Spray deck underside with lube.
4) Premium gas.
5) Premium plugs.
6) Synthetic oil.
7) Clean filters.
8) Repulley spindles for higher Blade Tip Speed.
9) Advance governor for higher RPM's to 3750.

Anyother tips on what works for you. I have to get the most out of what I have.
Thanks.


Your last sentence goes against numbers 6, 8 , and 9. According to my Kohler manual, synthetic oil is not recommended. As for 8 & 9, reengineering the mower is, IMHO going to get you the least out of what you have in the long run. If that needs an explanation then all hope is lost anyway. Your best advice in this thread was that you have a finnish mower, not a bush hog and that you need to mow when it needs to be mowed or dont take the job. As for the rest of the items on that list, they should be done with any mower regardless of the conditions of mowing.

tb8100
02-29-2008, 09:34 AM
of course synthetic is not recommended! They want you to buy more engines from them!

bohiaa
02-29-2008, 09:36 AM
as I recall 3600 RPM's. is what it's set too from the factory.

Roger
02-29-2008, 09:58 AM
These threads create a chuckle. The implication is that the user of the equipment can improve on the equipment, making changes on the work the engineers and designers of the equipment already finished. If some of these changes made the equipment better, wouldn't they have been done before it left the drawing board and went into production? If somebody is a better engineer and/or designer than those working for the manufacturing, then rid yourself of the equipment you own, and go to work for the manufacturer. I'm sure the money is better, the conditions are safer, less dirty, heat/humidity controlled, year-around paycheck, paid benefits, ....

The matter is similar to "what kind of oil should I use" threads. The manufacturer goes to great lengths to provide the recommendations that will ensure good life, especially during warranty period. Yet, others out in the field seem to think "I have a better idea -- those crazies at XXX don't know what is going on."

The initial post says the motor is low on power to do the job. Somebody suggested changing the pulley on the deck to make the spindles run faster. Running the spindles faster increases the power requirement. This suggestion is counter-productive to provide a remedy for a setup with an underpowered motor.

Green Pastures
02-29-2008, 10:09 AM
The simplest solution is to just mow it more often.

Tell the customer you will no longer be able to abuse your equipment, give them a reasonable NEW schedule, a new price and let the chips fall where they lay.

MarcSmith
02-29-2008, 10:25 AM
you could always Turbo it.....http://www.youtube.com/watch?v=qAGz4i2_Iuk

I have never repullied any mowers....but much like you can do gears on cars/trucks, you could do it...But again. can the spindles handle the extra rpms? you must make sure the blades are balanced much better....

how many of us have gotten rid of the crap filters that used to come stock and retro fitted with the donaldson style? thats called improving on equipment. How many have added suspension seats or flex forks...improving on design. how many have added drain tubes on their mower so when they change the oil it actually gets into the catch can.....improving on design....How many have added speed up kits to the Walker mowers, or OCDC, or hitches, or other accessories that the manufacture did not have available? Its called modifying the equipment to fit your need.

All_Toro_4ME
02-29-2008, 10:26 AM
The simplest solution is to just mow it more often.

Tell the customer you will no longer be able to abuse your equipment, give them a reasonable NEW schedule, a new price and let the chips fall where they lay.

Wise advice. Dont modify the engine in any way. If you do, you can void your warranty, not to mention reduce engine life. Mow it more often like everyone here has said and raise your blades.

TLS
02-29-2008, 10:37 AM
Have your dealer set the RPM's for 3750-3800 no load. (This is NOT a governor setting)

Mow grass.

tb8100
02-29-2008, 11:10 AM
These threads create a chuckle. The implication is that the user of the equipment can improve on the equipment, making changes on the work the engineers and designers of the equipment already finished. If some of these changes made the equipment better, wouldn't they have been done before it left the drawing board and went into production?

The answer is no. The engine manufacturers must create a durable product that is cost effective. If they only put top notch components on these engines, they would not be cost effective at the retail level. There are better cooling, filtration, and other such things out there, but the mower manufacturers must keep their models around a certain price point, which means compromising certain things.

basshunterrick
02-29-2008, 11:51 AM
I know I have read in a Kohler book to set rpms at 3600, but if I am talking to a Kohler
tech about an eng. problem they always say 3750 for the rpm.

puppypaws
02-29-2008, 12:36 PM
as I recall 3600 RPM's. is what it's set too from the factory.

WRONG, per Kohler operators manual and their spoken recommendation...

QUOTE:

Engine Speed
NOTE: Do not tamper with the governor setting to
increase the maximum engine speed.
Overspeed is hazardous and will void the
engine warranty. The maximum allowable
high idle speed for these engines is 3750
RPM, no load.

puppypaws
02-29-2008, 12:38 PM
WRONG, per Kohler operators manual and their spoken recommendation...

QUOTE:

Engine Speed
NOTE: Do not tamper with the governor setting to
increase the maximum engine speed.
Overspeed is hazardous and will void the
engine warranty. The maximum allowable
high idle speed for these engines is 3750
RPM, no load.

I know I have read in a Kohler book to set rpms at 3600, but if I am talking to a Kohler
tech about an eng. problem they always say 3750 for the rpm.

The mower manufactures say 3600 rpm's not Kohler.

basshunterrick
02-29-2008, 02:32 PM
Puppypaws I knew I read it or seen it so I looked it up. In a Kohler service manual 18 to
25 hp specs for torque, hp, and fuel consumption 1800 to 3600 rpms. I do not know about other manufactures. Dixie Chopper has always told me 3750

Roger
02-29-2008, 02:47 PM
tb8100 -- Thank you for pointing out the missing element of my explanation, namely the price point.

The other suggestions of upgrades may be appropriate, but at some cost.

puppypaws
02-29-2008, 04:10 PM
Puppypaws I knew I read it or seen it so I looked it up. In a Kohler service manual 18 to
25 hp specs for torque, hp, and fuel consumption 1800 to 3600 rpms. I do not know about other manufactures. Dixie Chopper has always told me 3750

"cajuncreole" is talking about a 27 hp Kohler and 3750 is recommended on this particular engine by their design engineers, the ones I have personally spoken with myself. I do not know the specifications on Kohler's lower hp engines.

TomberLawn
02-29-2008, 04:11 PM
I've often thought it would be cool to upgrade some components on a zero turn and bush hog pastures and things like that. My local Husqvarna dealer has a used Husqvarna with Mud Shark ATV tires on the rear. I just wander what it was used for.

puppypaws
02-29-2008, 04:33 PM
Puppypaws I knew I read it or seen it so I looked it up. In a Kohler service manual 18 to
25 hp specs for torque, hp, and fuel consumption 1800 to 3600 rpms. I do not know about other manufactures. Dixie Chopper has always told me 3750

"Command Series" 20 hp and up this is the operators manual statement for each engine, 18 hp states 17 hp at 3600 rpm's.

QUOTE:

Engine Speed
NOTE: Do not tamper with the governor setting to
increase the maximum engine speed.
Overspeed is hazardous and will void the
engine warranty. The maximum allowable
high idle speed for these engines is 3750
RPM, no load.

Audrey
02-29-2008, 08:49 PM
Mower manufacturers (similar to auto mfgrs) must also comply with situations concerning liability. Their only concern is not performance, but performance combined with the *least likely to get us sued factor*. They also factor in longevity. The machine is only supposed to last for X amount of hours or normal seasons. Manufacturers aren't going to put themselves out of work. Planned obsolescence weighs heavily as well.

I did the pully swap on my Scag 23hp/52 ztr. It was great on thinly sparsed weedy grass in the hot/dry months. It did help a little. However, after a good rain, it was an even bigger pooch than before. It also over-stressed the deck belt and broke it. I went back to the factory pully set up and left it alone.

I used different blade combinations to help. High lifts create more vacuum, but rob power. Try sticking with regular blades, or only use a high lift on the discharge side.

A

woodbutcher44
02-29-2008, 09:23 PM
:rolleyes:Your truck has the same crap in the owners manual too .BUT duel pipes aftermarket air filters larger tires tinted windows awinch fuzzy dice on the rear view.
WHAT THE HEII this is like watching a little leage ball team cry and moan because the were not enough colas after the game.
some of the best product improvments come from people in the field doing and showing the co's what improvments have been made.
If new things arent tried and done WE WOULD BE IN YARDS WITH SWING BLADES
now to each thier own and I will modify what I got if I see fit and maby one day one of these cos will write me a fat check for my idea. Untill then I'll mow:confused:

gene gls
02-29-2008, 09:59 PM
I have an Exmark 66" 27hp Kohler. I mow in South Louisiana and have quite a few old pastures to keep up 5-10 acres. They are in Bahaia some on former garden plots, so the grass is very thick.

I mow most once a week, but some every other week and during the spring on certain very thick parts of the plots with the throttle wide open, the Kohler 'boggs down" and I have to crawl through the area, to keep from stalling the engine out.

I went to the mechanic at the dealer, he is a very competent mechanic, and he said he would "advance the spring setting on the governor" and I should be able to get through this heavy grass without slowing down as much.

He said he would install a tach on the mower and I should never go over Kohlers recommended top end of 3600 RPM's.

I sharpen the blades daily, clean the deck daily and spray it with lube to keep grass from building up. I run synthetic oil and change filters as needed. Any thoughts??

Thanks,
Louis

Your engin does not have enough HP to run a 66" deck to begin with, even on normal mowing. Slap on a 30HP.

lifetree
02-29-2008, 10:17 PM
The simplest solution is to just mow it more often.

Tell the customer you will no longer be able to abuse your equipment, give them a reasonable NEW schedule, a new price and let the chips fall where they lay.

I agree ... this is the best advice !!