Power loss on hills

[lahanko]

I have a new Toro Z-Master 20 hp Kohler with 52-inch deck.
The machine has approximately 20 hours on it and I have noticed a problem with it while going up steep hills (more than 25 degrees). The motor bogs down like it is about to stall (real close).

The hill is in my back yard and I have gone up it many times with no problems. Today the machine was doing it every time I mowed up the hill. I tried the hill without the blades on and no problem, turned the blades on and tried the hill again, no problem, what gives? Runs great on the flat and once at the top of the hill where it levels out. The hill is about 60 feet to the top.

Could it really be the plugs already? I did notice black smoke at one point when I just happen to look back.

[Tvov]

Possibly your choke is not adjusted correctly. You may have to have the dealer look at it.

Also, with only 20 hours, you could have a dirty carb. Sometimes dirt or dust from the factory will get into a new engine and screw things up.

For both these problems, carefully go over with the dealer what the warranty covers. Years ago I got screwed because the warranty didn't cover "dirty carbs" (I didn't want to mess with blower because it was so new), and I got stuck with a $40.00 repair bill for a new machine.

Check to see that you don't have dirt/grass in the gas tank. The movement of the mower means that the dirt gets dislodged from the gas line inlet, but then eventually settles back down, causing problems. Also, if the dirt is not fully blocking the line, it will only make the engine bog when under load (like going up a hill), but not on flat ground. I had this problem last summer with one of my walk-behinds and it took forever to figure out what the problem was.

Hope this helps.

[Mowingman]

I had a similar problem with a Toro ZMaster 23hp Kohler and 62" deck. I bought it last year and needed it for a 3000' long screening berm between a landfill and a road. The slope on this berm is so steep that the uphill front caster wheel on any of my ZTR's is constantly lifting of the ground as you work across the slope. The Toro could not be turned uphill without the engine bogging down and sometimes stalling out. My other mowers with 22hp or 25hp engines would go right up the slope. I lived with the problem for 200 hrs, then sold it and bought a Grasshopper midmount diesel. It goes up the hill with no trouble. I wondered if Toro had some oddball gear ratio in their hydro. motors or pumps?
Maybe to get their speed up, they sacrificed power.:)

[Likestomow]

Pull the left spark plug. If it's fouled, you have a blown head gasket.

[TLS]

Fuel filter?

Fuel line pinched?

Something is preventing your carb from getting enough fuel. With it being new, have them check it out!

The newer TORO/EXMARK Z's have rollover shutoff mercury switches. I'm pretty sure that these are a ON/OFF type switch. Either it runs, or it's over on its back!

Let us know what it is!

[Albemarle Lawn]

Two of my Gravely 260Z mowers have this problem, both Kohler 25HP engines.

I'm glad you started this thread because I was about to start the same thread.

Mine will run well on hills only with the left hand side UPHILL (operator's left hand).

If the right hand side is uphill, the mowers stutter and spit and lose a lot of power.

(Sounds just like choke is on).

The engines in the Gravely are mounted with the air filter to the rear of the mower.

If the engine were mounted sideways, I suspect the problem would occur either going straight uphill or down.

Ken

[Albemarle Lawn]

Mine also give black smoke when they bog.

[awm]

if thats a command kohler,i have the same in exmark. it should pull any hill ,no problem . the black smoke of course would indicate carb problem. dealer adjustment should cover it.. .

[scottb]

We are using a 25hp Kolher and it never bogs down. So like some have said take it to the dealer you need to have it checked out.

[Brickman]

My Walker has the 25 Kohler. No problems with it. It will spin out, but nothing seems to wrong with the engine.

[lahanko]

Well I guess I found the problem on 6/2/02 but had to go out of town and did not have time to test until yesterday. A twig approximately 4 inches long was jammed up in the throttle linkage and or governor linkage. I had to look close; the twig was directly behind the linkage, (between the linkage and the motor) and running parallel with it. It almost looked like another type of wire linkage. How in the world the twig got there is beyond me. Anyway, runs fine now.

[captdevo]

Albemarle Lawn

the reason yours is doing this on one side and not the other is from it running leaner due to the configuration of the carb.

when tilted one way the needle is fully open, the other direction, the float is keeping it closed.

i've had a few walkers do this, i pulled the bowl off and adjusted the float level a little higher and solved my problem.

[65hoss]

A friend of mine in this area bought a new HP with the same motor. The dealer kept telling him it was in his head. He contacted eXmark and they in turn got him in touch with Kohler. Kohler told him that they have had a few problems and some of them have defective carbs. They sent a new one to the dealer and had it replaced. Problem solved.

[lahanko]

Well, I guess I didn't find the problem, did it again last night.

65hoss,
Was your friends machine a 2002, 20 hp?

[strickdad]

captdevo is right... the float is not adjusted properly.. run the unit on flat ground, stop and check air filter, look and feel and smell for gas residue. then run it up that hill get off as soon as you get to the top and check air filter again... i bet is has a higher content of gas in it this time..

[65hoss]

Originally posted by lahanko
65hoss,
Was your friends machine a 2002, 20 hp?

Yep! Call eXmark and get a # for Kohler.

[Jman]

Does your engine have the new style heavy duty air filter on it? Some of the new engines out this year have been affected by the filter. Something about the bowl vent is being affected on side hills upsetting the fuel mixture. Have your dealer contact his Kohler rep and see if they can help. There is a good chance they can get a carb to correct the situation.

[mowngrow]

check the air filter, kohler is bad about filters getting dirty quick, depending upon the conditions

[lahanko]

Yes the engine does have the new style heavy duty air filter on it.

I plan on calling Kohler in the morning.

The trouble with the dealer is he wants me to bring it in and I know it will be there for ever.

[lahanko]

Yep, new carburetor everything seems fine.
Two trips to the dealer and everything is good to go.
Believe this, my Toro dealer new nothing about the engine, carburetor and air cleaner problem.
I called an Exmark dealer and he faxed me the bulletin from Exmark describing the problem and the resolution from Kohler.
I in-turn walked into the Toro dealer ship and handed it to the service guy. Evidently Toro could not see fit to inform their dealers of the problem, I plan on e-mailing Toro directly. My dealer was a bit upset. Anyway problem has been taken care of, thanks to you guys and especially “65hoss”.

[65hoss]

Glad you got it fixed. :)
Its just too bad it took so long for you. Nothing is more frustrating than a new expensive machine having problems. Good luck!