Engine Question, 8 HP Briggs

Radar67 · July 20, 2010, 11:30:56 PM

Yeah I know, alot of you do not like Briggs, but it's what I have.

The engine starts and runs as long as I keep it at half choke. It has power, I cut 12 inch wide material with it today. It cuts about as fast as it ever has.

When I move the choke closer to the off position, it starts spitting and sputtering. Any ideas?

tyb525 · July 20, 2010, 11:38:13 PM

It sounds like it might be starved of fuel- a blockage in the fuel line, or a clogged filter in the tank? I have a 10hp Briggs that will only start with the choke on full even when hot, but once started it runs fine with no choke. Sounds like a lack of fuel.

customdave · July 20, 2010, 11:42:18 PM

Radar67, I had a 8hp briggs vertical shaft do the same thing, it was loose bolts carb to intake valve port on block, tightened back up I was in bussiness. Good luck....

Dave

Bill Gaiche · July 21, 2010, 12:32:41 PM

What I have found in this case is that the main jet is partly clogged with dirt or build up around the needle and seat. Remove and clean, blow air through needle seat. Also diaphram can also start getting stiff from age and does not flex so that it can do its job. Replacing that is easy.

brdmkr · July 21, 2010, 12:47:42 PM

The 18hp on my mill does this more often than it should. I just open up the carb and clean everything out and it works fine. Kinda like Bill says, I clean out pretty good around the needle.

Buck · July 21, 2010, 02:07:56 PM

yep....sounds like a blockage of fuel....start cleaning and blowing air thru and clear it out

Captain · July 21, 2010, 05:04:14 PM

Ditto Bill, Buck and Brdmkr

ladylake · July 21, 2010, 07:11:59 PM

Check for loose bolts first, then filter and carb. Steve

Dave Shepard · July 21, 2010, 07:54:30 PM

Is there any water in the gas? Isn't that a problem in this humidity with the alcohol content? We used to run 8 HP Briggs on the leaf blowers. They weren't bad.

Radar67 · July 21, 2010, 08:25:03 PM

The fuel is running through the lines good, and the carb bolts are tight. I will have to take the carb off and check for clogs, it could be build up. My filter is in line, so easy to check, I'll have to do that.

Dave, I've not had any problems with water in the fuel caused by humidity. The gas usually doesn't stay in the tank long enough for condensation to occur.

I'll have to take a closer look after I do some welding on it. I broke the loader a few days ago trying to get a log on.

r.man · July 22, 2010, 08:51:39 AM

Radar, a friend had good luck with one of the carb cleaning additives. His 12 hp snowblower got so bad he was running it on 3/4 choke. Put the cleaner in and went to 1/2 choke second use, 1/4 choke third use and then no choke from then on. Now if he could just remember which additive it was so I could get some for my lawnmower.