ford NAA bogs when hot

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ford NAA bogs when hot

manny rivera	just got NAA, while cutting 2 acers the tractor had an a few back fires. after 2 hours the tractor would not stay on at high rpms and would not run under load. the tractor would idel, got i home and all worked well at high and low rpms. any suggestions
Bob G	Sounds like you were starving for fuel. Check for fuel flow thru the carb if it happens again.
Jim Loveridge	Mine used to do the same thing. I thought it was a fuel problem too. In my case it turned out to be a bad ignition coil. It would get hot and loose good spark then when it cooled down it ran fine. But don't just start throwing parts at it. That can get spendy. If you have a volt meter you can trouble shoot when the tractor is acting up. Keep us informed and we can get to the bottom of it.
manny rivera	i now notice that the naa is idoling rough and has some more back fire. runs roungh for about 5 mins and start to backfire, stuter and quit, i let the tractor sit for about 2 or 3 min and turns on, run it and it act up again. already changed coil and naa did same thing.
Bob G	Remove plug on bottom of carb bowl and let the fuel run. should fill a pint jar in 2-3 minutes
manny rivera	hellow bob, i tryied to take the brass nut under carb bowl but it is very striped at the nut and left if alown for now, took the line out of gas cut off and gas flowed a a little less than 1/2 pint in three min, took off sediement bowl and flowed the same less than 1/2 pint. any help, my carb leaks and i notice that when the leak runs dry the tractor stars to bog down and back fire, let it idel low and leak come back tractor revs up good then start to act up again, do you think its a fuel problem and if it is what could it do, thank for your help up to know.
Jim Loveridge	Manny, It does sound like a fuel problem. There is a screen just above the sedament bowl. Make sure that isn't clogged up. Then there is another screen inside the tank on the fuel shut off valve. You would have to remove the whole valve from the tank and let it drain into something. May not be a bad idea. Also there is one more screen right at the carburator where the line enters. But here is a question. How much gas do you have in the tank?
manny rivera	removed sediment bowl and it was pluged up, that hepled that but tractor was still back firing so gave it a total tune up runs alot better but still back firing and runing rough at high rmp and under load. might be points gap and questions thanks for the help, the tank is about half way full.
Bob G	you may still have problems in the carb. might try adjusting the main jet. main be set too lean. point gap should be 0.025". also check the mechanical advance in distributor. use timing light to check the timing.
manny rivera	i set the points to .025 and the tractor starts right up good. idels well and runs good in 1st gear with little or no problems. its the forth gear and shredding that give it problems with back firing and loss of power. can you tell me where the main jet and how to set carb, and what do you mean by mechanical advances your info is greatly apreciated.
Bob G	The mechanical advance is below esthe plate that the points are attached to. as the motor increases in speed the flywieght move out and rotate the points so that they open earlier (i think)to advance the spark. see picture for the main jet. some people say to set it open from fully in 2 turns and leave it. I like to start about 2 1/2 yurns opena nd then wwith it running at full speed adjust in until the engine starts to miss and tehen open back up 1/4 or so. I don't think I would use 4th gear for any work, just a road gear. I bush hog in 1st or second gear. sometimes 3rd if it is real light. good luck
Bob G	I think the NAA carb is like the picture, if not shuld be close enougdh to get the idea.
manny rivera	ill check to carb mon afternoon, thanks for all the help the carb pic looks very similar the the carb on the tractor. any help would be great thanks
manny rivera	ok mr bob g, i turned the carb screw out and naa would not start, screwed in about 2 time and wanted to start, turned 1/2 and started, next i reved up and tried to ajust, runs smooth at idel but still a little power loss when trying to shredde with almost no back fire. do i keep screwing in screw to lean out mixture more or what else can if do.
Bob G	You can try and sdjust it some more, but if you are in more than 1 1/2 turns out from full in, you may need to overhaul the carb. turn it clockwise until it stops (by fingers only) then open 2 turns, should start there. sounds like it helped some.
manny rivera	ok, i found that the engine ran best with only one turn on main form all the way in, so i took off carb and cleaned it was very dirty and had some water in it, put it back and tractor does same thing, coughs and spits while shredding and when taking off in forth gear. what do you think. also noticed a small leak of oil on engine above exhast manifold but below valve cover what could it be. any help would be great.
manny rivera	bob you had said some thing about the distributors mechanical spark advance which is below the points how does this work, what is the correct procedue for setting the points, if any of these are off would the engine sputter and fart under load because this the only time it does it.
Bob G	If you just did a quick teardown and clean of the carb, you may still have dirt in the jets or passaways. You need to completely diasemmble and soak in carb cleaner for several days. then rinse in solvent and then blow all the passage ways out with compressed air. Use a rubber tip on air nozzle to get good pressure to all the passage ways. You can get an overhual kit which will include everything you will need. a compression test of the cylinders will give you a better look at the overall condition of the engine. A lot of auto parts stores will rent compression gages. Good Luck
manny rivera	to bob, i decided to try to tinker with the carb and was trying to shred, stop and ajust carb, sounded like it was getting a bit better when the engine just died, would not start, traced back to sediment bowl which was completley cloged with trash, dropped gas tank and found a good amount of rust, this would be a good start to clean tank to ensure carb is not getting starved of gas before tring to tune. ill be busy tommorrow but will post any improvments later. thanks
Bob G	Completely clean the tank. or replace if necessary. It will be a constant source of problems if you don't. Good Luck
manny rivera	hey i noticed when i took the gas tank off the naa i noticed some oil leaking form the left side of tractors engine (if sitting on seat) around or above exauhst manifod but below the plate with the bolts next to valve cover. what could it be from gasket or what.
Bob G	I am not that familiar with the naa engine. Maybe Jim and tell you somthing.
Jim Loveridge	Manny, I can't think of anything except the valve cover gasket that could be leaking where you describe. The distrubutor has counter weights under the plate where the points and condenser are. As the rpm's pick up those weights move out and cause that plate to move, advancing the spark. But it sure sounds like you have found your problem with the conamination in the gas tank.
manny rivera	well jim i droped the tank and cleaned well with citic acid and rust colors came out. took off carb, disasembled, and gave it a good soaking in solvent and cleaned up pretty good, im going to see if the problem is fixed if not going to buy carb rebuit kit next, any other ideas for the tractor boging down under load like trying to shred.
Bob G	During the cleaning of the tank, make sure the stand pipe part of the sediment bowl is not plugged. The top end of the screen is open and dirty fuel can and will geet into the stand pipe. Mine was just about plugged solid last year.
manny rivera	hey bob, now that you said stand pipe sediment bowl, it look like the prevoious owners cut it off flush with the part that screws into gas tank. what do you think, any way i cleaned the carb and put back on and tractor ran better but still under powered when trying to shred, tractor picks power back up in about 10-20 second after shredder is engaged. but i can tell its under power because when cluch is pushed in while shredding the rmps jump right up to high. what do you think spark or carb, might need to tune carb better, have autolite 216 spark plugs with car wires, new everything.
Bob G	You car wires, you need solid copper core spark plug wires. What do you mean by shredder? Make sure it does not require more power than your machine is rated for. Check the governor for correct function. If you do not have one, get the correct service manual for your tractor. It will explain how to check the governor. I would replace the sediment bowl. sounds like you are gaining on her. Keep it up!
manny rivera	ok, i changed the wires to soild copper, changed plugs to 437 auto lite and put back freshly cleaned carb, and ran a can of carb cleaner in tank, the tractor will idel all day long and at a park, rev up fine. the tractor will now shred grass at a medium high gear but still getting a few back fires from exhasut when in first gear and trying to cut grass a full rpm, the tractor is much better but still having a few problems an the highest rpm range with the tractor under load. i need to change the wire that go in and out of resitor noticed blue arcs the other night. what do yall think.
Bob G	If you are seeing arcs at night then you have a problem. fix it, whatever it takes. Good luck
manny rivera	ok i changed every single wire on the tractor, and check gap and wires for conectivity all was good. my oil pressure is about 25 at idel and 40 at full rev. all looks good, BUT, the tractor still has a few backfires at high rpm while under load and just noticed some burbs through carb, but over all the tractor is running and shredding grass much better, any coments on the backfires while under load and burps in carb.

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