In my quest to find something to mow my excess acreage I have ended up with a Ford 8n (51 vintage) and ford 951 5' brush mower. It seems to be pretty solid but has a couple of things that need attention. It starts well and idles smooth as a kitten but when wrapped up especially under a load it sputters and slobbers - doesn't die, keeps on mowing, just sputtery. It sounds to me like ignition - bad wires, dist cap or associated but someone in another forum answered a question like this for someone else and said carburetor. So far I have just cleaned contacts of plug and coil wires, looked at points (didn't look like enough gap, so I opened them up - don't have specs on gap) and adjusted carburetor mixture screws. Neither of these seemed to have much effect. Put some gumout carb cleaner in the gas tank and mowed for an hour or so. It actually seemed to act better the longer I mowed, but when I started it up cold later it seemed to be like it was at first. Any experts out there with direction for a newby Ford owner?
Calling on Ford 8n experts here - questions
- Thread starter bland
- Start date
Thanks for the input. Am at work, but will check tonight. I did look at air cleaner, but just saw that there appeared to be plenty of oil. But maybe too much. This tractor had been setting and it might be that someone just filled this up and got it too full. I assume you are saying that too much oil could restrict air flow to carb - right? It does have overrunning clutch, but it does this even without pto in gear. It seems to be strictly rpm or throttle position related. I mowed some more on sunday and if I held throttle to 1/3 or so position, it runs smooth and still pulls the mower probably as good as wide open. I slowed engine speed down and went higher on gearing and still was able to mow. The governor idea might be something also. It could be running up against a governor that was dropping it out at lower than normal. Tach is broken, so I don't have any good idea what rpm's I am at. Sounds like some good starting points. I will probably have a lot to learn on this thing.
higgy
Platinum Member
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- Kuota L3130, Ford 9-n, Allis AC, and a JD 4020 with powershift
The 8N's have a Marvel/schleber carburator on them. I have found that the top to bowl gasket on that type of carb get dry and distorted causing an air leak. When this happens the engines do not run well, they sputter cough and act badly but rarely die.
It is an easy fix if that is the problem. Napa carries rebuild kits for the carb if that is the problem.
It is an easy fix if that is the problem. Napa carries rebuild kits for the carb if that is the problem.
Soundguy
Old Timer
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- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
a 51 should have a side mount ignition coil. Plug gaps are .025.. and you should use a champion h12 or al 437 plug... OEM spec has an h10 / al216.. the hotter plug helps with the depoits in the modern no-lead gas.
Points gap on the sidemount is .025.. pointsgap on the frontmount is .015
Wires need to be copper core wires.. not modern anti radio static carbon wires. TSC and most hot rod shops sell metal core wires.
Carb kits for that MS 241 carb are available everywhere.. small kit is 20 bucks.. has no needle replacements.. get the big 35$ kit.. has new idle and mainjet needles.
Get a copy of an I&T fo-4 manual.. it is decent reading for the N series.
To adjust the downpointing mainjet on that carb, set it to about 1.5 turns out.. turning out enriches the mix.
the side idlejet screw adjusts for max rpm.. IN enriches.. adjust it about 3/8 of a turn in, as a start.. then adjust for max idle rpm.. not smoothest idle rpm. Behind the carb is the throttle set screw.. adjusts rpm. There is also an rpm adjustment onthe governor.. but you need the fo-4 for that one.
There are 3 fuel screens.. one in the top of the tank on the fuel bowl.. one in the fuel bowl.. and one in the elbow from the fuel line to the carb.
Check your points, plugs, cap, and wires. TSC has a pre-packaged set of points, cap and plugs.. grab that, a set of wires for 20$ and the carb kit if you need it.
Check for carb halves vacume leak or carb to manifold vacume leak by spraying a squirt of ether or propane from an unlit torch right around the carb just after you start it.. if the engine speed changes.. you have a vacume leak. Could even be inthe 1 piece manifold.. or at the manifold to block union. Does choke help it?
Sounds like it may be too rich.
Email me if you need more info.
Soundguy
Points gap on the sidemount is .025.. pointsgap on the frontmount is .015
Wires need to be copper core wires.. not modern anti radio static carbon wires. TSC and most hot rod shops sell metal core wires.
Carb kits for that MS 241 carb are available everywhere.. small kit is 20 bucks.. has no needle replacements.. get the big 35$ kit.. has new idle and mainjet needles.
Get a copy of an I&T fo-4 manual.. it is decent reading for the N series.
To adjust the downpointing mainjet on that carb, set it to about 1.5 turns out.. turning out enriches the mix.
the side idlejet screw adjusts for max rpm.. IN enriches.. adjust it about 3/8 of a turn in, as a start.. then adjust for max idle rpm.. not smoothest idle rpm. Behind the carb is the throttle set screw.. adjusts rpm. There is also an rpm adjustment onthe governor.. but you need the fo-4 for that one.
There are 3 fuel screens.. one in the top of the tank on the fuel bowl.. one in the fuel bowl.. and one in the elbow from the fuel line to the carb.
Check your points, plugs, cap, and wires. TSC has a pre-packaged set of points, cap and plugs.. grab that, a set of wires for 20$ and the carb kit if you need it.
Check for carb halves vacume leak or carb to manifold vacume leak by spraying a squirt of ether or propane from an unlit torch right around the carb just after you start it.. if the engine speed changes.. you have a vacume leak. Could even be inthe 1 piece manifold.. or at the manifold to block union. Does choke help it?
Sounds like it may be too rich.
Email me if you need more info.
Soundguy
Keep em comin - I can have lots of questions - that is the way I learn - ask those who have been there. - Thanks
Now so far weaseled in a few minutes at a time I have done following. I had checked spark plug wires Saturday and found those newfangled carbon ones, so I went and got a set with real wire - figured I had found the problem - but apparently not. I had set point gap by eye - I know bad - but they were barely opening and I have a pretty good eye - but no change. This evening checked oil in breather - a little bit high - poured some out - slightly too much - will have to top off now - didn't seem to be it. I have adjusted mixture screws - felt I had them close - did this right off without change. Don't have a carb kit but checked bowl screws today - two were loose - tightened them and put a bead of silicone around joint to see if it would help. Suspected screen in tank but sediment bowl is always full so discounted that - need to check the one in carb and sediment bowl (is it after bowl or before?) Watched the carb throttle butterfly linkage to see if governor was dropping it when it falters, but it stays rock solid and governor appears to work otherwise. After all this it actually seems smoother at higher rpm's unloaded, but still slobbers under load - the higher it's rapped the more prevelant it is. Never quits, doesn't backfire or anything like that. I mowed Sunday evening for 1.5 hr with throttle set at about 1/3 on lever - really fast idle almost, mowed in 2nd and 3rd gear pretty heavy stuff and it just walked on through it as well as when it was almost full throttle. Don't have a local tsc - so will try to order points, cap and carb kit. Have some champions h12 and will see about getting them in. Thanks - better shut up now.
Now so far weaseled in a few minutes at a time I have done following. I had checked spark plug wires Saturday and found those newfangled carbon ones, so I went and got a set with real wire - figured I had found the problem - but apparently not. I had set point gap by eye - I know bad - but they were barely opening and I have a pretty good eye - but no change. This evening checked oil in breather - a little bit high - poured some out - slightly too much - will have to top off now - didn't seem to be it. I have adjusted mixture screws - felt I had them close - did this right off without change. Don't have a carb kit but checked bowl screws today - two were loose - tightened them and put a bead of silicone around joint to see if it would help. Suspected screen in tank but sediment bowl is always full so discounted that - need to check the one in carb and sediment bowl (is it after bowl or before?) Watched the carb throttle butterfly linkage to see if governor was dropping it when it falters, but it stays rock solid and governor appears to work otherwise. After all this it actually seems smoother at higher rpm's unloaded, but still slobbers under load - the higher it's rapped the more prevelant it is. Never quits, doesn't backfire or anything like that. I mowed Sunday evening for 1.5 hr with throttle set at about 1/3 on lever - really fast idle almost, mowed in 2nd and 3rd gear pretty heavy stuff and it just walked on through it as well as when it was almost full throttle. Don't have a local tsc - so will try to order points, cap and carb kit. Have some champions h12 and will see about getting them in. Thanks - better shut up now.
RobertN
Super Member
Silicon and gas are a bad mix. Won't help around the carb bowl; it will get slimey and fall away. Knew someone who used it to seal a sending unit in a gas tank. It got all funky and dropped in the tank. Jeep quit running, and when look at filter, it had an orange silicon worm in it. Made running Rubicon kinda hard when the worms kept getting in the fuel line /forums/images/graemlins/blush.gif
Check Napa; it is amazing the things for old cars and tractors that they have... Bet they'd have a rotor/cap/point set, or could easily order it.
Check Napa; it is amazing the things for old cars and tractors that they have... Bet they'd have a rotor/cap/point set, or could easily order it.
I just ran a silicone bead around the outside of carb bowl where it meets the body of carb. Didn't put it in between the bowl and body. Just wanted to try to stop or slow down any air leak if there was one. I know where you are coming from about using silicone where it can get in gas. Thanks for the heads up though. It was actually permatex high temp gasket sealer that I used, might not be silicone at all. Also, went out between slight showers here and put the new plugs in - old ones looked fine actually, but went on with the new - didn't seem to change anything though. Not sure where to go next - need to get carb kit, manual, and maybe new cap and points I guess. In the meantime, I'll just go on using it I suppose.
FOUND IT !!!! - Maybe something new to add to the list of possibilities - found the screw opposite of the points that holds the plate that the points are on down was loose - tightened it and - problem apparently all gone. Oh, well new plugs and wires never hurt anything even if it didn't need them. Thanks much for everybody's input - I am sure I will have many more questions. Oh, by the way - I know that this tractor has hydraulic fluid in trans and diff - fairly recently changed. Not really sure what kind. But there still seems to be no real agreement as to whether it should have the 134 hyd oil or 80 or 80/90 gear lube - does everyone agree on what to use or are there several different opinions as it seems to me?
1savoy
Gold Member
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- B26, ZD323-60 and JD JX75 currently. Previous: L3800 HST w/ BH77, JD301-A , JD450C Dozer, JD 330, JD F525, Ford 4000, Farmall H
Bland,
Use the 134 Fluid. The Ford's use that in everything, even the power steering if you had it, except the engine. Your New Holland dealer has it and can give you the amount needed for the tranny and rear end. Good luck with your tractor.
Russ
Use the 134 Fluid. The Ford's use that in everything, even the power steering if you had it, except the engine. Your New Holland dealer has it and can give you the amount needed for the tranny and rear end. Good luck with your tractor.
Russ