Anyone rebuilt a B&S carb?

[stuckmotor]

I've been starting my Snapper rear engine rider by priming the carb for years and am thinking maybe I should rebuild it. Not wanting to over do things I decided to ask our memership exactly which part goes bad and causes the carb to lose it's prime. I'm thinking the float needle. I can get one for a little less than $5.00 while a complete carb kit is more than $60.00 Is it the float needle?

 

[quicksandfarmer]

Have you priced a complete new carburetor? I've had great results with that. I get them on Amazon or Ebay, often less than $50.

 

[TomSeller]

On small engines anymore I just buy a replacement carb. Much faster than rebuilding and (depending on the model) might not that expensive.

 

[Spanner]

Quite often the 'Choke' butterfly is not closing completely when activated. Operate the throttle control right through to the 'Choke' position and then check for further possible movement at the Choke Lever on the carburetor itself. You can adjust the cable on the 'throttle control plate' (where it is secured by a screw-clamp) to push the choke lever to fully closed.
The B&S engines are running lean for C.A.R.B. emmissions compliance so you need complete choke to ensure starting. That you are 'priming' the carb to start suggests you don't have full 'Choke' closure to me.

This simple adjustment costs ... nothing.

Also make sure your float bowl is clean and has no water in the bottom.

 

[DJ54]

If the fuel tank is located away from the engine, and lower than the carb., it's more than likely an internal check valve hanging up, letting gas run back to the tank. I had this happen on my old Wheel Horse 5-6 years ago. And happened to my BIL a couple years later. They would eventually start, but seemed like forever, before it picked up the fuel, from the rear mounted tank.

The easy fix was getting a can of Seafoam fuel treatment. I was never one to believe in snake oil, or a mechanic in a can, but this stuff works. The biggest problem these days, is dealing with ethanol laced gas, and the problems in using it. One treatment cured both mine, and the BIL's problems of the carbs. losing their prime. Apparently cleaned up the gum that was not letting the check valve seat.

Now, when I fill my fuel cans for all of my lawn & garden engines, they get pretreated with Seafoam, and Stabil. Even now in the Spring, both of the identical Wheel Horses start up, like I just shut them off.

It will only cost you $6-$7 depending on your location, but that is the price here locally. It's just one of those products you have to try to believe it.

 

[stuckmotor]

Thanks to all for the answers. The carb is below the tank so I don't think the problem is a check valve. I'll check the butterfly and if that's not it a new carb might be the way to go.

 

[Brotherdan]

Spanner's advice is a great start. I recommend a carb cleaner that advertises dissolving varnish instead of the bargain brand. I think I used a gumout or gunk product. Carefully remove the carb and really clean the throat and flap while working the flap. HERE'S WHAT'S IMPORTANT. Set the carb aside and let it dry and work the flap. If there's any resistance over how it moved while cleaning it, clean that choke pivot again...until it's smooth. Also, clean ALL the linkage moving parts, even the stuff you don't think does anything. Doing that and setting the valve gap made a huge improvement in starting, running, sound and power.

 

[Snobdds]

I have found more often than not, it's the gasket on the float bowel. It gets old and lets air in. Then I just clean out the needle valve and jets with carb cleaner and it good for another 10 years.

 

[jclaudii]

if you get lucky you can find an exploding diagram on the net somwhere by googling your carb model # or your machine model number and go to the fuel section. For any carb that is having issues you need to pull it off, clean it decently to keep debris out and take it apart. Once it's apart you can easily find out if it was corrosion (white flakey stuff in bowl) usually due to water or just condensation, varnish will be sticky and gummy in there, and the last part is to clean the little passages. Air is best followed by tiny wires. I picked up a torch tip cleaning wire set at Tractor supply for like 5 bucks and it has some tiny little wires that are perfect for sticking into holes to see if something comes out.

Before you go to blasting compressed air, look at the needle and the seat area (where the needle goes) to make sure you won't be blowing the little doughnut shaped seal out. What usually happens is the seat goes bad if it is a Original piece due to ethanol or age. The seal will swell and cause less fuel and/or poor needle sealing or premature needle sealing causing the fuel bowl to not fill up correctly. If it is alot older it won't have a little rubber/nitrile seat and it will just be a metal contact surface for the needle. Either way make sure you don't blast that oring seal out and use a tiny pick to pluck it out or blow it out into a paper towel/rag.

 

[stuckmotor]

More informative replies. The one just prior to this message is most like what I was expecting based on the fuss about ethanol and complaints about carbs around the time I bought the Snapper. Many thanks.