BCS 850 fuel problems

cmyoung2 · Jul 29, 2014

Talked to Joel yesterday. He said he really didn't work on many Briggs, had him baffled too. Today I took the fuel pump off, it started blowing gas out the vent tube, maybe a little too much pressure or not enough of a float valve seal? Anyway, hooked up to the Bio 100 and chipped for over an hour, no problems, and some of it was fairly large limbs as well as a lot of brush, so it had to work. Then hooked back up to the bush hog, 10 minutes and it started dying again. Is it just the steep slope? and it's really not that steep, I can stand and walk on it. Barely

And it is a fuel problem, fires fine with a little ether, so it is fuel not electrical. I would consider re-engine with either a Honda or a diesel, but need to get it paid for first, which is difficult if it is not dependable.

wstr75 · Jul 29, 2014

Is there a fuel pick-up tube inside the gas tank? If so, maybe the tube is sealing itself off in a corner when the tractor is mowing on a hill.

cmyoung2 · Jul 29, 2014

The tank seems to be a good design with a sump low in the center. There has been enough fuel to cover the pickup hole, and all the lines are new. Good thought though.

Bentleg · Jul 31, 2014

Does it matter which way it is leaning, which way you are crossing a slope? Sounds like a float hanging...

cmyoung2 · Aug 1, 2014

At first it seemed to be worse with the left side down, but now it doesn't seem to matter. It could be the float, I might have a chance to take it apart again tomorrow. Not real sure how to fix that.

super55 · Aug 2, 2014

Where I used to work we had a walk behind mower that had a B/S Vanguard on it that would die out. Same type of symptoms your describing which led us to believe it was fuel related. We never really ended up fixing it but found out our culprit was a low oil shut off sensor in the bottom of the crankcase. When we got it on a pitch all the oil would run to one side and the sensor would ground out the ignition. Get it back on level ground it would crank right back up. Finally we just disconnected the wire. We knew when we had it on too much of a slope when it would start spewing out blue smoke. I don't know if yours has a low oil sensor but if it does it might be worth unhooking and see if the motor still does what it's doing.

cmyoung2 · Aug 2, 2014

Mine does not have the low oil sensor, I don't think. And it will still fire, with ether, just after it dies, just will not continue, so I still think it is a fuel issue. What worries me is I may be on too steep of a slope. I measured and it appears to be about 25-30 degrees, not%. It shouldn't be a problem, I can walk it, the mower is stable, and some of the literature says you can bale hay at 45 degrees.

wstr75 · Aug 3, 2014

CMYoung, the thread below may be helpful. Please scroll down to the arthurgreen Sept 16, 2007 comment. His fuel starvation problem troubleshooting found a crushed connector to be the problem:
Briggs & Stratton 18HP engine problem - Tractors Forum - GardenWeb

My guess is when running the chipper, the use is intermittent and thus the fuel consumption is less overall than when running the mower under constant heavy load.
Bill in NC

wstr75 · Aug 3, 2014

On another topic, I saw where you had your 725 listed on Craigslist here in North Carolina a couple months ago and you recently mentioned it sold. I am planning to sell my 737 on Craigslist here in NC and would love to hear if you got your listing price for your 725. I felt your asking price was appropriate and reasonable.
Thanks,
Bill in NC

cmyoung2 · Aug 3, 2014

Bill,
I got just about my asking price, unit went to Knoxville TN. The price was just tractor and tiller.

wstr75 said:
On another topic, I saw where you had your 725 listed on Craigslist here in North Carolina a couple months ago and you recently mentioned it sold. I am planning to sell my 737 on Craigslist here in NC and would love to hear if you got your listing price for your 725. I felt your asking price was appropriate and reasonable.
Thanks,
Bill in NC