B&S 24 HP Intek running rough

[rclint]

I have a Craftsman DYT 4000 with a B&S 24 hp Intek. It has been running really rough last cutting, then this time it started skipping enough to notice, before it was more of a surge. I replaced the air filter this spring, and cleaned the carb and air filter/pre cleaner last week. It started up a lot better, and ran for about 1 hr before doing the same thing again. I also noticed with the surging it only done it when it got hot. I also changed the furl filter last week as well, lots of what looked like rust around the outside of plastic bowl (loose) mower has a plastic gas tank.

The mower has been kept well, has 100 hours on it at present. I use Stabil for the gas. I purchased it on sale new, the next season time for grass cutting and at 8 hours the left intake vale stuck. I removed the head, pushrod was bent and valve had a lot of glued on carbon gunk. I cleaned it off, fixed the bent pushrod, polished it, set valve clearance and no problems until now. I consider this one of the worst purchases I have ever made, the motor in my opinion is junk to have this many problems already !! If anyone has had, and fixed this problem I would appreciate some pointers. I also changed the plugs last season trying to fix the surging problem, I'm thinking it has got to be in the carb since it did help for a little while, but how to fix the problem for a short time.

 

[rclint]

Posting another pots to go with the above...

I have been running a straight 30 wt in the mower per owners manual, I thought about using a 10w30 and using a synthetic as it would be really cheap option in such a small quantity, and once a year oil change. All season long on this oil however it has not even changed color, still honey colored (Castrol 30 weight), and gasp I didn't even change the filter this year as I refused to pay Sears the price... been meaning to do a cross reference to another cheaper filter. From what I understand this is not a full pressure lube system, I'm not sure how it works... the thought has crossed my mind to use a by-pass filter that uses some type of cheap element to filter maybe a small canister using cotton ?

If they ever make a simple fuel injected (real multi-port) it will solve so many of the carb problems on these small engines.

 

[JTK]

Being intermittent, I would guess at a carb or contaminated gas issue. When it sputters does it smell lean or rich? Could be a fuel pump on it's way out passing bubbles or starving the engine. I'd probably run a synthetic 10w30 or Shell Rotella-T 5w40 in hot Georgia summers. Yep, Kawasaki makes fuel injected and liquid cooled V-twins for mowers. Kohler does too I believe.

Joel

 

[rclint]

I assume it's running lean as no black smoke, and no smell. I ruled out the fuel pump because I ran it out of gas in order to refill with fresh gas to see if that was the problem. It has a gas bowl under the carburetor with what appears as a electronic vale metering orifice, a bit hard to get to so I have not taken that off yet. I have taken the top plate off and sprayed the jets etc out with carb cleaner. I also notice today while tinkering with it some that the pre filter is already full of dust with less than an hour or grass cutting. Maybe I need to add a big thick foam pre-filter for the air cleaner.

 

[JTK]

Yep, the fuel cut-off solenoid slams the main metering needle shut when power is killed to the solenoid. The bowl stays filled with fuel, but nothing gets out of the carb to prevent spill-over, etc. Another simpleton thing is the gas cap vent. When it acts up, loosen the gas cap to see if it stops. If it's leaning out on you, it's gotta be fuel supply problem.

Joel

 

[Steve S]

Have you drained the carbs float bowl to see it a bit of water is the cause . Do all the simple stuff fires .

 

[rclint]

A update, and the least thing I would have expected. I cleaned the plugs (just a wipe down) to check and see if the plugs would give any indication of the problem, when I replaced the plugs last year or first of the spring I remember putting some of the stuff on it to keep the spark plug wire cover from seizing to the plug. The silicon or whatever it is migrated way up the wire, and gobs of dirt/gunk in there. I used a electrical contact cleaner and cleaned all the mess out, and it runs fine now. I'm thinking I wiped them out with a q-tip before when cleaning the carb, but missed all the gunk up in the wire. I hope no changes, I did clean the filter before this and no change, cleaned to spark plug wire boots and instant change.

Clint

 

[RWEST]

Quote:
it runs fine now.

Yes!!!

 

[rclint]

Just one more update !!

I cut my Daddy's yard last week, about a 3 hour job (big yard). When I first started the engine I thought oh boy here we go again, no time to worry over it, so I just started cutting, forgot about it. About an hour into the job I stopped to get some water, left the engine at idle, when I came back I thought wow that's the best it's ran in a lonngggg time. I think with the above cleaning of the plugs/wires, carb, filter etc and a fresh tank of gas run thru it really solved all my problems, and mot likely had some varnish build up in the carb somewhere and the fresh gas cleaned it out. I plan to use Stabil year around now. Just wanted to make a last update in case another pour soul had the same problem.