49 B carb adjusters have no effect

Looking at the archives tells me I need to clean out orifices, drill em out, etc. Is that my last hope? I don't relish the idea of attacking a carburator with a drill unless I have a real good idea of what I'm doing. At least now I could probably limp it down the road to a repair shop.

It has DLT 13 cast under the bowl.

Thanks

Ray

(A) FUEL PROBLEMS

1) When you say you have a nice stream out the petcock, I assume you mean the carb bowls bottom drain cock right??? If a stream of gas runs out there continuous a couple minutes, then you know for sure theres enough gas gettign through the needle valve and seat so it and the sediemnt bowl and tank inlet must be supplyign sufficient gas.

2) You say you turned the adjusters both out 2 turns. The initial rough in settign is for the idle needle out 1 3/4 to 2 turns but the load needle out 3/4 to 1 turn. Try that then tweak once shes running. When you say however too far out makes her backfire, it sounds like shes then gettign too much gas (especially if she black smokes out the stack then) meaning the adjuster does have some difference after all.

3) Now, if the bowl is gettign sufficient gas (sounds like it is) but she lacks power due to fuel starvation (after needle adjusting dont cure), the problem may be the float level is set too low OR the carbs main center vertical brass nozzle has some restrictions.

a) With the bowl removed, you can pull (may need to drill and tap it then use screw and washers and nuts to back it out, careful, if you pry at the top in the carbs bore, you may bend or crush it)) the brass nozzle and clean and wire brush it and clean each and every lil side horizontal hole. Restrictions in the nozzle can cause insufficient fuel and low power.

b) The float level should be set to rise to approximately level when it shuts off gas flow through the needle valve and seat.

4) If the engine wont idle down nice and slow and smooth (dont sound like thats your problem though) thats when you could have the clogged idle circuit passages where you mentioned drilling out passages. If thats the case, you have to remove the brass drill plugs, usually after heatign them, and then use the correct extra long aircraft No 40 and No. 53 drill bits (ONLY in the 3 passages shown, not any smaller ones) which takes the pasages to their correct size and use MIG welding wire or steel guitar strings to clean all the other smaller passages. For a picture of the drill plug locations and what size bit to use, go to

Link

5) Other causes of poor idle or rough runnign may be a vacuum leak, which sucks in air leaning out the mixture. To check for it, use an unlit propane torch or WD 40 or Carb Cleaner etc and with the engione running spray it all around the carb, especially the throttle shaft bushings (good place for leaks) and the base of the mainfold, and if she speeds up, thats likely where the source of a vacuum leak is.

NOW, if the carb checks out, loss of power could be ignition related, so i will give you a few tips in that direction.

IGNITION

1) Due to the relatively low cost, I would first try a fresh new set of Autolite 388 plugs.

2) Next, another possible cause is the points may have developed oxidation while setting. If they are only gray oxide coated, but otherwise look good and smooth, try to clean/polish them and check the gap, 0.015 if a mag and 0.022 if a distrubutor. If they are burned or pitted or carboned up bad, REPLACE THEM.

3) With the plugs removed but their wires attached and their sides up against ground, turn her on and crank the engine over and insure BOTH plugs produce a good visible blue spark. If not with good points gapped right and good plugs, post back what kind of ignition you have (mag or distributor and type) and I will guide you further. Be sure you also have good wire core, not auto carbon suppressor type, plug wires.

SUMMARY, FIRST, you need good clean fresh water free gas. Old stale gas can cause power problems and you might as well look at the air cleaners lower bowl to see if its clean and no water. NEXT, Be sure you have good clean correct gapped points, good plugs and wires, a good blue spark, and then try the needle adjusters again. If the ignition is good and gas flow to the carb is good, then suspect the float level is too low or the nozzle is clogged. If she wont idle down smooth, then look at the web site above and consider drilling out the passages behind the brass drill plugs and cleaning out all the other smaller pasages and look for vacuum leaks.

HOPEFULLY HOWEVER, maybe a fresh set of plugs (or wires) or cleaning or new points and tweaking the needles is all you need. Try the cheaper simple things first, cuz it probably needs that stuff anyway, before you tear deep into the carb if you dont want to tackle that job.

Post back and let us know how it turns out.

Good Luck n God Bless

John T Nordhoff in Indiana

~Because your tractor ran good when put away last fall you probably have varnish or rust in the carb body casting or internal passages. Does running with the choke partially back on help the tractor run better? If so you probably have a carb problem.

~Seeing as you have good fuel flow THROUGH the carb [did you let the fuel run out the bottom of the carb for at least 30 seconds?]. If not make sure you do to eliminate just seeing what's in the float bowl]. Your problem is more than likely inside the carb & possibly a plugged passage.

~You say it now idles good [that is good news] so more than likely your problem is in the load system. Probably the place to start is to pull the float bowl off the carb [you can do that with the carb still on the tractor], be careful you don�t put too much force on the lower bowl nut as the carb stem BREAKS OFF RATHER EASILY & is expensive to have repaired.

~Once the bowl is off, you should pull the MAIN NOZZLE & clean the little holes in the side of that nozzle [common problem & probably your problem]. That main nozzle sits in the channel that's above the bottom nut that holds the float bowl on. To get that nozzle out either run a tap about 3/8" into the bottom of that nozzle & then use a bolt or [piece of all-thread] & a couple of washers to pull that nozzle out the bottom, or run a sheetmetal screw a short ways into the bottom of that nozzle then clamp on a vise grips & give the vise grips a swat in the downward direction with a hammer [DO NOT PRY ON THE TOP OF THAT NOZZLE or damage could result].

~If the nozzle holes were plugged you can probably re-assemble the carb, then try it to see if that was all of your problem. If the nozzle holes are not plugged, then see if the little by-pass hole in the bottom of the stem is open [tends to rust shut].

~When re-assembling the carb make sure the float top is set parallel to the carb bowl gasket casting, then re-set the load needle to 1 turn out from seated.

~If the above doesn�t make it run correctly you will have to pull the carb & remove ALL the passage brass plugs & run a small wire or even the proper sized drill bits through the passages. Seeing as it now idles good you probably won�t have to mess with those drill bits as those are mainly for the idle circuit. CAUTION: don�t run any drill bits through anything until you are sure you know where they need to be run & have the proper size. If you manage to drill out the wrong passage that carb will never meter correctly again.

~If you need to take the carb apart & clean those internal passages, post back or E-Mail & I will send you a carb breakdown showing the holes & passages that need cleaning.

~Your problem sure sounds like it�s fuel related but every once in a while an ignition issue will act like a fuel problem. To be sure [especially if you don�t find a carb problem] it wouldn�t be a bad idea to install NEW spark plugs & clean or replace the ignition points. If the points are oxidized they could possibly cause a weak spark & therefore a miss under load. The same with the spark plugs, if they are partially fouled they could be misfiring under the higher compression of engine load..

A couple of guys who know their stuff are Burrey Carb in Monroeville IN and Roberts Carb in Iowa. That's if you want to go full boat with a carb rebuild, and aren't sure about the skills of the local repair shop.

As it was running well last year, an Italian tune up might work, and save you from a job you don't want - carb rebuild. Clean the sediment bowl making sure you clean the screen on top. Remove and blow out the fuel line and any screen it might have. See if you can blow from the fuel line back into the tank as sediment might have accumulated there as well. Set it fairly rich then let it run and run and run some more. Sometimes these things heal themselves, or at least follow the old addage - the more you run it, the better it runs as the crud in the jet eventually blows away. If you're real daring, a bottle of carb cleaner stuff from WalMart might help - but with old machines it sometimes loosens up more junk in the tank than you had to begin with, so tread carefully with that fix.