MF 1643 Intermittent Stalling/Power Loss

onionfmr · Feb 12, 2011

Intermittent stalling/loss of power problem has been happening more frequently lately. This is the same problem that I had last fall while mowing where the tractor just lost power and wouldn't run over 1250 RPMs. Shut it down and everything was fine. The other day, while plowing, the engine got loud, lost power and wouldn't rev. over 1250 RPMs. Shut it down and let it sit for awhile. I checked battery connections, fuel bowl and filter, all electrical connections (I could find), tank was full (don't like to run below 3/4 tank in winter due to condensation), checked all fluid levels. It is not the seat switch as I temporarily disabled it to check out the tractor. The fuel isn't gelling (using PS), it is almost like it is starved for fuel temporarily. Put everything in neutral and restarted it and it ran okay. Seemed to have a slight vibration over 2000 RPMs and maybe a little low on power with tach needle bouncing a little above 2000 RPMs. So, I put it back in the building. Yesterday, I ran it for a couple of hours w/o a problem. No vibration and power was good again.

Are there any known problems with the 1643s? Almost feels like there is something in the fuel tank blocking the flow or the fuel pump isn't running right. When the fuel gets lower, I'm going to check to see if I can find anything in the tank. Any ideas on this problem? I have a spare fuel filter and was going to change it out and bleed the line.

It has been a great tractor! Tractor bought new in Aug. 2010. Less than 50 hours currently. My dealer is working with me on the problem. Location of tractor (500' from main road, no easy access) and my situation with heavy snow (over 165", so far this year) make this situation a little more difficult. I'm just looking to see if anyone else has had similar problems, if so, possible solution. My concern is that one day when I really need it to plow, it won't go.

Any help is appreciated. Thanks - Ted.

onionfmr · Feb 24, 2011

I will post updates, as I go with this, in an effort to possibly help somebody else (if they encounter a similar problem).

Update - tractor ran fine for 7 straight hours over 4 separate uses. Checking over the tractor, we have found nothing out of the ordinary. Last time out, problem showed up again. I was running with a half of tank of fuel and heading up a slight grade. Not very steep, but still a grade. I'm starting to think this has something to do with the fuel pickup in the tank? Filled up the tank with fuel, tractor ran fine for another hour. I have read that MF 2625s have had issues with the placement of the fuel pickup in the tank causing similar symptoms. Any other ideas? Anybody else have any issues running with a 1/2 tank of fuel?

Thanks for any and all help - Ted.

MF 1532 · Feb 24, 2011

Sounds like something could be in tank . I had a friend with a new Ford suv , picked up from dealer went on vacation the next day . It " ran out of gas " with 3/4 tank . It did it the whole trip . Dealer pulled tank to put a new one on , and found a piece of tape in the fuel line

I hope this might be of help to you . I would rather something fall off , as to have a problem like this to detect .:confused2:

roger4400 · Feb 24, 2011

Hi. I do own a 1643 and I did not had any problem with it. On my opinion, It looks like your engine is starving, Try to loose a little your fuel cap on your tank, maybe there is no breathing by there and there shoulb be, otherwise there is a negative pressure in the tank because your engine call for fuel and with time it has to sucks too much to get fuel and is starving...so loosing the cap will give sufficient air and no negative pressure will built. ( sorry for the bad english explanation, I'm french and do my best to be as clear as possible in english):thumbsup:. Roger

MF 1532 · Feb 24, 2011

I had a new JD mower that acted like this . I finally noticed there was a small vent hole in fuel cap , it was stopped up with dirt . The hole was so small I used a torch tip cleaner to unplug . Mower would run fine , then start sputtering and quit .

gary d · Feb 24, 2011

I had the same problem with my 1532 on the first day I got it.
I called the dealer and he told me to check the seat safety switch.
Sure enough the seat belt got between the seat and the frame and would not allow the seat to activate the switch. Removed the seat belt and running fine since. You might have a bad or mis-adjusted switch. Makes the tractor want to stall out when you try to drive it .

onionfmr · Feb 26, 2011

I really appreciate all the replies and ideas. This problem is definitely annoying. Engine definitely feels like it is getting starved for fuel (when it happens) as it won't run under power, but will maintain idle.

gary d said:
I had the same problem with my 1532 on the first day I got it.
I called the dealer and he told me to check the seat safety switch.
Sure enough the seat belt got between the seat and the frame and would not allow the seat to activate the switch. Removed the seat belt and running fine since. You might have a bad or mis-adjusted switch. Makes the tractor want to stall out when you try to drive it .

I was having problems day one with the seat switch, so that has been addressed and fixed. I don't believe that this current problem is electrical.

MF 1532 said:
I had a new JD mower that acted like this . I finally noticed there was a small vent hole in fuel cap , it was stopped up with dirt . The hole was so small I used a torch tip cleaner to unplug . Mower would run fine , then start sputtering and quit .

I'll check for a vent hole.

roger4400 said:
Hi. I do own a 1643 and I did not had any problem with it. On my opinion, It looks like your engine is starving, Try to loose a little your fuel cap on your tank, maybe there is no breathing by there and there shoulb be, otherwise there is a negative pressure in the tank because your engine call for fuel and with time it has to sucks too much to get fuel and is starving...so loosing the cap will give sufficient air and no negative pressure will built. ( sorry for the bad english explanation, I'm french and do my best to be as clear as possible in english):thumbsup:. Roger

I'm going to give this a try and report back if this makes a difference.

MF 1532 said:
Sounds like something could be in tank . I had a friend with a new Ford suv , picked up from dealer went on vacation the next day . It " ran out of gas " with 3/4 tank . It did it the whole trip . Dealer pulled tank to put a new one on , and found a piece of tape in the fuel line I hope this might be of help to you . I would rather something fall off , as to have a problem like this to detect .:confused2:

I spoke with the dealer again today. They have located two tractors exhibiting the same symptoms as mine. Both had something in the fuel tank blocking the flow, one a sheet of paper and the other a piece of cellophane. Once I run the fuel down in the tank, I'm going to look around for something.

roger4400 · Feb 26, 2011

Hi again, When new, my tractor had his brake pedal set too tight.....so when hot (after +- 2 hours mowing this happens with HYDROSTATIC ONLY ) when I was pushing the forward pedal, instead of increasing the engine rpm ,( let say I was going 2200 and tried increasing to 2400 if accelearing) the rpm were decreasing to 2000 or little lower instead of increasing to 2400. The dealer sent someone home and loose the adjustment of the brake pedals ( both of them) and This never happened again . He explained to me that the hydraulic oil temp, being hot after a few hours, made the brake plate to take some volume and they were applying pressure and braking the tractor ( that is often seen on bigger tractor) so when I was pushing the forward pedal harder, the tractor was applying the brake harder causing the engine rpm to slow instead of accelering . This is another **easy** thing to fix if it is your problem.

Good luck and give us a feedback. Roger

1648nc · Feb 26, 2011

I don't know if they are different styles but my grandad's 2605 in tank screen at the pickup was clogged from day one. It would barely pull the tractor, let alone anthing else. He told the dealer what he needed and they gave him the fittings and line and external inline filter and he did away with the in tank screen. The tractor has twice the power now, it was absolutely starved for fuel and wouldn't do much above 1/4 to half throttle. They didnt know what was causing it but he figured it out and fixed it himself since they were scratching their heads. My 1648 will be here friday so I guess i'll find out if they have similar pickups.

onionfmr · May 24, 2011

Thought I would post an update in hope that it will help someone else if they encounter a similar problem. I completed the 50 hour service about 30 hours ago. When changing the fuel filter, noticed pieces of plastic in the filter and bowl. Almost looks like pieces of plastic threads from the top of the tank fill where the cap screws on. Have run the fuel tank down to almost empty and no reoccurrence of the problem, so far. Keeping my fingers crossed. The real test will be during winter plowing. Have to wait and see.