B7500 losing power

[OLD GAR]

My beat up B7500, along with hard starting has developed a reluctance to run over 1250 RPM. Push the throttle on up and it acts like it is flooding. Pours out black and white smoke I did research the B7500 thread but no joy there.

 

[Bulldog]

When was it serviced last, fuel filter, air filter, ect?

Does it have clean, fresh fuel?

Has it sat around with old fuel in it?

 

[North Idaho Wolfman]

Along with the points that Bulldog brought up, try running it and when it starts to lose power remove the fuel cap and if it gains power it has a clogged vent.

 

[lugbolt]

Black and white smoke when the engine is loaded, or accelerated, is generally indicative of starvation for air.

 

[OLD GAR]

The air starvation might makes some sense. I've only done minimal service. I don't do dusty mowing or heavy digging or grading with the FEL. I do some toting back and forth, but no really hard usage. I usually put about 3 or 4 gallons of fuel a month so it isn't stale. I buy it at the local Chevron station in town. It really smokes if I put full throttle but won't do over 1400 revs. I also suspect some low compression for he just won't start without a loooonnnnnggg cranking time. I just give him a tiny breath of ether and he starts ok. This isn't just a new thing as I've had this clunker for about 4 but the refusal to develop reasonable revs is fairly recent. I live in west central Louisiana so the cold isn't a factor. I will save some other issues for another post.

 

[OLD GAR]

Thanks for the response! All of you were on the right track but what the "LUGBOLT" put me on to was the exact solution! I opened up the filter can and although it didn't look "too bad" I took it out cleaned out the canister and snapped it back in place without the filter. As soon as I started him up, two seconds of black smoke and smooth as silk, he just ran right up to 2500 revs! Thanks a lot fellows for getting me going again.

 

[Bulldog]

I opened up the filter can and although it didn't look "too bad" I took it out cleaned out the canister and snapped it back in place without the filter.

I wouldn't run it any without a filter. It would surprise you what just a short amount of run time it will take to trash your engine. We had a pissed off employee at the quarry ruin a 3408 Cat engine in less than one day running it without a filter. $150K lesson learned the hard way.

 

[D2Cat]

Yes, OldGar, you better listen to Bulldog. He has described a situation called "dusting an engine", you can/will ruin an engine in short order without an air filter.

 

[alansz400]

I was surprised how much black dust came out of my air filter when I blew it out a few weeks ago. Seems like the exhaust coming out under the hood and the fan blowing it around and the air cleaner inlet being under the hood send the black soot right to the air cleaner.

 

[rentthis]

That small amount of ether is begging for trouble