Outdoor Power Equipment and Small Engines - Rebuilt carb, still surges

Just rebuilt carb for my craftsman 5.5 hp Tecumseh engine and it still surges. replaced needle, seat, float and hinge pin, main nozzle and o-rings and cleaned the entire carb with carb/choke cleaner. engine still surges. the carb is getting fuel (checked that). the only thing that i can think of now is replacing the high speed bowl nut on the bottom. it seemed like it was a little gunked and there are some parts i could't get to. but the carb cleaner should have reached those parts, right?? i am at a loss here and can't think of anything else. any help apppreciated.

Engine: Craftsman part number 143.975501

You should be able to get the high speed nut clean. Did you buy a rebuild kit? PN# 632760

Surging is the carb starving for gas. Check your float level, also did you remove the side welch plug and idle restrictor screw and spray cleaner in there heavily? A bath type cleaner is the prefered method, often just using spray cleaner you have to hit spots multiple times. Also check your linkages to be sure all are moving freely.

If you will clean the bowl nut your problem will be solved. I use the wire from a twist tie, clean the 2 holes at the bottom, the tiny one that is about midway up and the hole down the center, then blow it out with brake parts cleaner(doesn't leave residue) and you should be good to go. Have a good one. Geo

First, spray cleaner is only useful on flaky buildup, not on varnish. Second, for less than $4 and if you have a local small engine shop, you can purchase a new bowl nut/main jet rather than hope to get yours good and clean as it needs to be in order to eliminate governor hunt/surging. The Tecumseh part number for the main jet is 640059.

alright monday I'll buy the new bowl nut and give it a whirl. i'll let you all know how it went! thanks

Not sure if it applies to a tecumseh but after the carb is off/on a briggs the static governor setting must be re-done. I had this problem with my 12hp and the reset solved it. One test was holding the gov. fixed and see if surge stops and runs fine or runs bad like starved for fuel.

FYI, simply removing the carb will not cause any misadjustment of the governor static setting, only loosening the governor arm screw will cause this and there is no need to do that when only servicing the carb.

FYI, simply removing the carb will not cause any misadjustment of the governor static setting, only loosening the governor arm screw will cause this and there is no need to do that when only servicing the carb.

Well, there's a fellow on the forum at www..com that will disagree with you on that. In my case the governor arm screw was never loosened but I pulled the carb and bottom cover (including the governor mechanism on the cam) and it surged consistently for weeks until I did the static reset.

I have to agree with Puey61. The governor should never need adjusting unless component replacement or internal damage has occurred. It is set from the factory, and usually won't even need resetting even if you change carbs. If yours was surging after carb removal, then something changed int he process of removal and reassembly (a linkage bent a little, or spring stretched), or the carb was running too lean. If a linkage was bent some, then resetting the governor could have compensated for it.

It doesn't hurt, however, to adjust it if it is done properly.

In my previous life, I ran a lawn and garden equipment dealership with my father, but I left that 24 years ago.

However, surging was a residual problem with a dirty carb and certainly after allowing gas to go to varnish deposits. When people came in to buy their own carb rebuild kits, more often than not, they didn't know what to do with the welch plug, or just didn't bother. When they finally brought it in to be ridden of the surging problem, if they had done a good job cleaning it otherwise, removing the welch plug and spraying cleaner, then blowing the chamber out with compressed air almost always was all I had to do.

However, the reason I am here today is because after all this time, I have two snowblowers I just bought with carburetors to go through that had old gas left in them until varnish deposits developed. I've tried two carb cleaners only to find that they don't work like they use to. Guess they've been made "safer" which = ineffective, huh?? What are you guys using that works in 2007?? I'd prefer something I can let them soak in for a day or so. Please forgive me if you see this in a seperate post.