JD 750 excessive exhaust and power loss

[rmroper]

My JD 750 4 wheel drive tractor has started putting out more exhaust than normal and seems to have lost some power. Any guidance will be greatly appreciated.

Thanks,

[kevin37b]

Depends on what ( more exhaust ) is. If it is white , it's unburned fuel . If it's blue , it's oil .If it's black , it's excess fuel . Might be air filter . Might be rings . M ight be an injector or the injector pump. Have you got decent dealer or mechanic in your area ?

[pedalstomper78]

Let's start with the color of the smoke and start to do some diagnostics from there. One step at a time with no assumptions is what we need to do. Smoke usualy gives a clue as to where the fire is.

Does it do it all of the time or only under a heavy load?
Any fluid levels going down?
Check your collant, oil, etc. If they are down a touch, it's not a reason to panic yet....especially if it's been a while since you've checked any of them.

[Gary Fowler]

My first thought would be a dirty air cleaner. Pull that and clean or replace if you havent done so in a while and see if that helps.

[RAnway]

We have had 3 tractors come through with serious brake linkage problems. Found all of them with Brake pedals frozen down due to cross shaft rusted and RH pedal mount on shaft also frozen to the cross shaft. All the units came in with the same problem of loss of power, and serious smoke problems. Freed them up and solved all!

[rmroper]

H Folks, sorry it took me so long to reply (business trips). All the fluid levels are ok, but it does need an oil change and transmission fluid change. Air clearner is just a little dirty (I did blow it out just in case. The power loss is noticable anytime I try to make it go faster... The hydraulics fluid lines to the loader are coated black from the exhaust. The exhaust is excessive whenever I drive it, hard to tell if it is excessive at an idle. When I drive it it is not obvious that the exhaust is black, but the smell will give you a headache fast.
I did work it pretty hard with a rototiller and then I ran out of fuel (my bad). I replaced the fuel filter, but had some difficulty getting all the injector lines to bleed. I also replaced the air cleaner at the same time (it was really dirty after the rototilling). I finally got it started. It is a 3 cylinder engine and have been told by a neighbor that it might be 1 or all three injector or the injector pump.

I will check out the brakes. I can get on a slight hill and see if it rolls freely.

Could working the little tractor be the cause of the excess exhaust / power loss? Right now it isn't much use.

I really appreciate all your guidance. Thanks

[rmroper]

I checked the brakes today (suggested in this thread). No problem rolling down a slight incline.

[Tx Jim]

Since you've changed the fuel & air filters I suggest having the injectors tested and possibly check inj pump timing.

[kevin37b]

Check the hose from air filter to engine , and make sure it is not collapsing at high throttle . I've seen this happen onturbocharged engines which yours is not , but would have the same effect . Make sure you have those injector lines snugged up also.

[SLHawkins]

If you had trouble getting all the injector lines to bleed, more than like you still got air in the system. Did you fill the filter with fuel before you put it on? My recommendation would be to bleed the lines again. Is it hard to start as well? Check the fuel line from the tank to the injector at the fittings/clamps. I had s yanmar fx32d that was giving me similar problems. Turns out there was a hairline crack in the fuel line right under the clamp at the fuel injector. It doesn't take much. It is sucking in air from somewhere. Make sure all the fuel lines are tight. If they are all tight, check the hose going into the injector. Pull it and squeeze it to see if there are any cracks.

Hawk