My Perkins powered M-F seems a bit down on power

[def38]

I have noticed lately that when mowing areas that were done without the engine governor having to go to the limit, requires more intervention by the engine governor. The Perkins runs and starts like new without wet stacking ever, no smoke at start, no black smoke when loaded and uses no engine oil. I routinely ad a bit of Diesel Kleen to the fuel. About 700 hours showing. I'm not the original owner so I do not know the service history (valve lash setting, etc.). I have changed the oil more frequently that specified using only Mobil Delvac 1300 15W-40 and a Wix oil filter. The air filter is new (50 hours ago) and clean. So what could be causing what I perceive is a slight loss of power? Does the CAV pump need service? Do the injectors need service? Would valve lash out of spec cause the power loss? Could it be fuel grade?

Diesel experts, what's your assessment?

 

[VroomVroom]

Fuel filter?

 

[def38]

Could be. I have not changed it since ownership about 70 hours. I will look for a quality replacement (I'll likely choose Wix) which I can order on line with free shipping.

Any other thoughts?

 

[K5lwq]

I would not rule out a problem with the mower.

Does your dealer have a dyno? Maybe they would see if it is close to specs.

 

[def38]

I would not rule out a problem with the mower.

Does your dealer have a dyno? Maybe they would see if it is close to specs.

The M-F dealer has no dynamometer and the mower bearings and belts are in excellent shape. When disengaging the PTO, it takes the flail drum about 15 seconds to come to rest. I think I'll set valve lash this coming winter. If that doesn't help, I'll remove and have the injectors serviced. Also, I'm going to remove and sharpen the hammer flails and weight check them for balance.

 

[Smokeydog]

Air filter?

 

[K5lwq]

The governor opening up a little more but you still can mow at the same speed as before is very little power loss. It could be just the hotter weather right now. You might notice an increase as things start to cool off.

One thing is certain, if there is a problem it will get worse not better. Then probably a lot easier to diagnose. Good luck!

 

[kthompson]

I would replace fuel filter and check air filter and if mowing a lot air filter are subject to quick clogging depending on what you are mowing. One thing you are not considering is you are getting more familiar with the tractor, mower and the area you are mowing. It is very possible you are taking wider mower cut due to learning how to position tractor to get full width of the cut. It is possible with summer heat and rain anything as heavy as ours has been this year really quick growing grass. We are not mowing our yard 3 times in 2 weeks and may yet end up twice per week due to how fast it is growing and yes our mowers are cutting heavy grass compared to normal. It could well be you have developed an ear for your tractor and equipment and are picking up on sounds now you were not before. Remember once had issue with a noise in a vehicle I could hear but shop could not find. Asked what should I do, owner of shop said turn the radio up a little. Was not long before noise lever of the generator was loud enough to locate the issue. lol

 

[BrokenTrack]

Most likely it is a clogged fuel filter.

At 700 hours, it would not be the CAV Fuel Injector.

 

[def38]

I'm also thinking that my grass/weeds/brush is getting thicker (the Buick hubcaps are pretty much gone now as are rocks and logs) thereby requiring more power to mow what was less dense last year. This means adopting a more frequent mowing schedule to keep things under control.

 

[BrokenTrack]

I'm also thinking that my grass/weeds/brush is getting thicker (the Buick hubcaps are pretty much gone now as are rocks and logs) thereby requiring more power to mow what was less dense last year. This means adopting a more frequent mowing schedule to keep things under control.

This does happen.

I mow the sides of the road from July 3rd Mid September, and my first two weeks I get my best production because of how the grass is. I have to drop down a gear about mid-July to do the same work.

I have also noticed my work has gotten tougher over the years. When we first did this, we were mowing saplings, brush, ferns and crap...stemmy stuff, and I can mow that just fine. It is those flat bladed grasses that rob horsepower! As we have continued to mow, the grass has now come in thick everywhere now, so I have to drop down into A range, instead of mowing in the lower gears of B range (what amounts to gear 3 and 4, instead of 5 and 6 as in years past). On wetland grass, I have to drop down into 1st gear, and on really thick grass, slip the clutch in first gear, or take 2 mowing passes.

But that is not really power. The tractor has the same power, I can just travel faster while accomplishing the same amount of work in less dense grass.

If the OP is losing slight power, then it most likely is the fuel supply: either air (doubtful) or fuel.

Mine will lose some power when the fuel goes below 1/4 of a tank because it does not have as much pressure pushing it past the fuel filter.

I also lost power sporadically one time when a wire fell on the exhaust and had melted the rubber and grounding out on the bare wire.

 

[Tx Jim]

My guess with only 700 hrs of use on tractor is clogged fuel filter or poor fuel flow rate from tank to inj pump.

 

[Molalla1]

My guess with only 700 hrs of use on tractor is clogged fuel filter or poor fuel flow rate from tank to inj pump.

Yes Jim or he might be getting used to the power . . . :confused3:

 

[Jim Nelson]

I am a firm believer in start with the easy/cheap things first, like filters. Injectors are neither easy or cheap for most of us and I would have to find a lot of reasons to go there. Follow the old KISS formula.

 

[BrokenTrack]

With only 700 hours, it has nothing to do with wear.

Perkins might require oil from their prone to leaking, but they will run forever.

 

[def38]

With only 700 hours, it has nothing to do with wear.

Perkins might require oil from their prone to leaking, but they will run forever.

No leaks. I have never had to top off the engine oil between changes. Wish I had a Perkins in my automobile.

 

[BrokenTrack]

No leaks. I have never had to top off the engine oil between changes. Wish I had a Perkins in my automobile.

They put plenty of Perkins in cars and trucks...

The Perkins engine I have for my generator came from a Reefer Unit on a truck, but they were originally designed for a diesel car in 1958. In 1992 they were last made for generator units for the British Military, but are best known for use as Marine Diesel Engines. The 4.108 engines was used on everything with 500,000 made, and a 34 year production run! That is a well designed engine.

 

[def38]

My Perkins 3 cylinder in the M-F has quite a growl to it. I wear hearing protection as a result. I have thought about a new muffler with chambers and baffles but, that might upset the scavenging of the engine when it is working under load. Any thoughts about this?

 

[TBone]

I have noticed lately that when mowing areas that were done without the engine governor having to go to the limit, requires more intervention by the engine governor. The Perkins runs and starts like new without wet stacking ever, no smoke at start, no black smoke when loaded and uses no engine oil. I routinely ad a bit of Diesel Kleen to the fuel. About 700 hours showing. I'm not the original owner so I do not know the service history (valve lash setting, etc.). I have changed the oil more frequently that specified using only Mobil Delvac 1300 15W-40 and a Wix oil filter. The air filter is new (50 hours ago) and clean. So what could be causing what I perceive is a slight loss of power? Does the CAV pump need service? Do the injectors need service? Would valve lash out of spec cause the power loss? Could it be fuel grade?

Diesel experts, what's your assessment?

X4 on changing the fuel filter first. As an old retired truck driver I always kept a spare filter or two in my truck and could tell in a heartbeat when mine needed to be changed. The quality of the fuel, the cleanliness of the containers you use and the method of refueling all determine how often it needs to be done. I've owned several tractors (including a MF 231S) and IMO Perkins are the best diesel engines out there for farm equipment. I (almost) wish my Kubota had a Perkins.

 

[def38]

Well Mr. Bone, your Kubota engine is also high quality and well designed. I have a small disp. Kubota diesel engine that powers the 7.5 kw generator in my motorhome. It is very reliable and quiet.