Warped Flo-Jet carb body

[mmischni 0]

Hi guys, Was rebuilding the carb on my 64 landlord. It has the large 2-piece flo-jet carb. My briggs manual says to make sure a 0.002" feeler will not pass between the halves of the body when assembled with gasket or the surface is warped. Well, I apparently have a warped carb body half. The manual states that replacement of the upper half is the solution. I was wondering if any of you have come up with any other solutions. I was thinking of thicker gasket, maybe some form of sealer... But I was wondering if this is a common problem with a common (non-replacement!) solution. After the carb rebuild, the engine still perfomrs the same. Runs ok at idle while cold, but when throttle is advanced it fires only intermittently and sometimes dies. Once it is warmed up, it runs the whole throttle range just fine. I am assuming this is excess air leaks through the warped body (and the worn throttle shaft...)? Thanks in advance!

[landlord2110 41]

had same problem with my landlord 2110-bought new carb body and worked fine. my muffler is close to carb so if you can shield muffler from carb it might help.

[HubbardRA 19]

It sounds like you may also have your carb set too lean.

[mmischni 0]

Well, Roy, I didn't even check on a new carb body, thinking it would be NLA or $$$. What did a new carb body set you back? Were you able to just replace the upper body? Or did you replace upper and lower? As for a lean mix, I have the fast mix screw set dead center of the rich and lean stumble points, and it accelerates great when warm. Is it possible that the lean condition is air leakage through the warped body that decreases when that hot, hot muffler heats the carb up a bit? Still interested in possible "hack" solutions if any exist :) Thanks! Matt

[firefoxz1 4]

Mine was warped on the early B10 I aquired this spring. The trottle shaft was tight so I just filed it flat again and rebuild it. Works great. I have done this with old Kohler and Tecumseh carbs where they meet the block as well and have not had a problem. I just go slow and even with the widest file I have continually moving where I'm filing.

[TimJr 206]

Air leakage into the mixture from a warped upper or lower body isn't the problem. The mixture of air and fuel happens elsewhere in the carb. Your warped gasket surface will only cause a fuel leak though, which is obviously a fire danger, but the engine will still run fine. Try filing one or both parts of the carb - use prussian blue dye on the gasket surface of one part, then stick them together to check your high spots and go back to carefully filing. The lower half of the carb can be easily sanded with say 600 or 800 grit paper on a good, hard flat surface. If the throttle shaft is worn, replace it and the bushings, or install bushings if it doesn't have them. 2 reasons - it will mess up air/fuel mixture, and you are sucking in diry air, which will wreck your piston/bore. Try leaving the choke on a little when it's cold - let it warm up for a few minutes. Needing choke for an extended period is a clue that your jetting is too lean, or you do have an air leak, and by cheating with the choke, you are getting it to run OK. Just my thoughts, Tim

[landlord2110 41]

I replaced upper body($47.00) in 2001 and made a shield around exhaust and carb

[mmischni 0]

Thanks very much for the info, everyone. There is a nice granite surface plate at work, so I will try to determine which half is warped and set it right with a file/abrasives. I will plan to replace the throttle shaft bushings as well. If I recall, these parts for a small one-piece flo-jet were not more than a couple of bucks. Does anyone know if the bushing or the shaft is the most likely to wear? Slop in the assembly is 0.018", but the shaft only measures about 0.003" under at the worst wear point. Thanks again! Matt

[HubbardRA 19]

Matt, On the carb adjusting, you should find the points where the engine starts to run rough and set the main jet in the middle as a first step. This should be done at WOT. Then set the idle mixture the same manner. After these settings, you should push the throttle wide open quickly and look for stumbling. If it hesitates or stumbles then richen the main jet just enough to eliminate the stumble. This is the one adjustment that most people do not do. If this adjustment is not made, then you can have problems when the governor kicks the throttle open suddenly.

[mmischni 0]

Hey Rodney, My manual does mention richening the mix if there is hesitation on acceleration. However, with my situation, I am pretty sure that is not the case. On cold start, it will ONLY run at idle speed. Trying to increase speed even very slowly causes it to cease firing regularly. It will fire maybe every 4 revolutions or it will die. However, if I run at idle for a couple of minutes, it will slowly let me increase rpm, until I am able to run full throttle. At this point, it accelerates smoothly from idle to full governed speed. Now I am not saying that my issue is not a lean mixture, cause I still have a sloppy throttle shaft, but even richening the mix does not help the issue at cold start. So far it is not a terrible deal, cause it only takes a few minutes to warm up, but I someday I will want to find out what the problem is :) Thanks all for the discussion and tips! Matt

[toomanytractors 0]

Hi Matt- A clean piece of glass works well for a flat surface for checking for warpage. Mine came out of a door window for a DM Mack truck. This also works well for resurfacing a cylinder head by using duct tape to fasten down a sheet of emery cloth on top of the glass and sliding the head back and forth on that surface. I use this method to finish off gasket surfaces after cleaning with a hand held wire brush. Also, if your throttle shaft and bushings are worn it will suck air and put everything out of wack. Hope this helpssm01--Dave