Billy4130

Carburetor or electrical problem on U-6 and U-264 Power Units

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If it will run on starting fluid, the ignition system is close enough. Might not be perfect, but close enough.

Dumb question: Have you tried to use the choke? These aren't computerized fuel injected engines. They need choke on initial startup.

Of course it should pick up fuel and run after being kept running with starting fluid for a few seconds.

What do the plugs look like after cranking for 30 seconds on full choke?

I don't think any fuel is getting up into the engine, and that's a carb problem.

 

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18 hours ago, Matt Kirsch said:

If it will run on starting fluid, the ignition system is close enough. Might not be perfect, but close enough.

Dumb question: Have you tried to use the choke? These aren't computerized fuel injected engines. They need choke on initial startup.

Of course it should pick up fuel and run after being kept running with starting fluid for a few seconds.

What do the plugs look like after cranking for 30 seconds on full choke?

I don't think any fuel is getting up into the engine, and that's a carb problem.

 

Yep. Tried with choke open, and closed. Also tried manually choking it with your hand with the air cleaner tube off. That does make it *try* to fire up, but never actually stays running.

I tend to agree that it is probably a carb problem, but the thing does not have a lot of parts, so it is frustrating to figure out why that seems to be the case.

The original plugs I pulled out were fairly dark and black, indicating a rich fuel mixture. After running it on starting fluid so much, its just dry and gray'ish colored.

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if you...it were closer would check 3x timing  with ALL marks and valves , piston   seen them jump to being put back-together 1-2 teeth off.....go ahead and move the timing 20-25* from 2;30 position both ways for test.....

then check for vacuum leaks  (vacuum gage in provided test hole//)? then...... gas proof tape other etc 95% block off the intake ( will need a drain for extra gas) and keep adding holes until it runs long enough to drive 50' out

talk with the other 303 owner on here.....

and thru supper thought that since it is 2 hours away,and rich (not firing) plugs  would take along some known   hot working cap and wires and c-86 plugs......not necessarily new out of box....  1 bad and or 2+ weak could cause this

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Just and idea, have you tried checking TDC vs the rotor in the distributor? I once had a 2404 that the PO had swapped the distributor 180 degrees and it would still run. It would drive on flat ground, but you really had to get going to make a hill. The lack of power and the noise gave the issue away. It sounded like a 2 cylinder JD.

Guessing that there are no major problems with the engine, you can systematically go through the possible issues by simplifying them in categorys: electrical/ignition, fuel/air, or timing 

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34 minutes ago, FarmallMMark said:

Just and idea, have you tried checking TDC vs the rotor in the distributor? I once had a 2404 that the PO had swapped the distributor 180 degrees and it would still run. It would drive on flat ground, but you really had to get going to make a hill. The lack of power and the noise gave the issue away. It sounded like a 2 cylinder JD.

Guessing that there are no major problems with the engine, you can systematically go through the possible issues by simplifying them in categorys: electrical/ignition, fuel/air, or timing 

Yes - now it was a little unscientific since I didn't have a way to run a dial indicator down into the cylinder, but using the old screw driver trick while turning the fan by hand, I got pretty friggen close to TDC, and the rotor was lined right up with the cap on the firing cylinder's contact based on firing order of the block casting (4-2-3-1 from memory?). So it may be off some, but it  can't be too much. I brought a timing light the one trip to try and find a notch or mark on the crankshaft pulley, but couldn't find anything, and too bright during the day to do much good with that anyhow. It runs so good on starting fluid, I mean like literally will run, I don't think its an ignition deal, but who knows.

 

 

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9 hours ago, mmi said:

if you...it were closer would check 3x timing  with ALL marks and valves , piston   seen them jump to being put back-together 1-2 teeth off.....go ahead and move the timing 20-25* from 2;30 position both ways for test.....

then check for vacuum leaks  (vacuum gage in provided test hole//)? then...... gas proof tape other etc 95% block off the intake ( will need a drain for extra gas) and keep adding holes until it runs long enough to drive 50' out

talk with the other 303 owner on here.....

and thru supper thought that since it is 2 hours away,and rich (not firing) plugs  would take along some known   hot working cap and wires and c-86 plugs......not necessarily new out of box....  1 bad and or 2+ weak could cause this

I did message the other guy from that link that had the 303 also. No reply yet. I had the distributor out when I replaced the condenser, because the screw was stripped and I had to get the thing pulled out and stood up vertically where I could get a screw driver on it good. I had marked it with some chisel points before I pulled it, and should be okay, but not ruling out the possibility of being a tooth or two off also, but never back fires when running on starting fluid either.

Is there a plug in the intake, to put on a vacuum gauge? I had not noticed or saw anything like that, but had been wondering/thinking along similar lines. 

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55 minutes ago, Billy4130 said:

Yes - now it was a little unscientific since I didn't have a way to run a dial indicator down into the cylinder, but using the old screw driver trick while turning the fan by hand, I got pretty friggen close to TDC, and the rotor was lined right up with the cap on the firing cylinder's contact based on firing order of the block casting (4-2-3-1 from memory?). So it may be off some, but it  can't be too much. I brought a timing light the one trip to try and find a notch or mark on the crankshaft pulley, but couldn't find anything, and too bright during the day to do much good with that anyhow. It runs so good on starting fluid, I mean like literally will run, I don't think its an ignition deal, but who knows.

 

 

Oh, ok. I'm not completely familiar with your power unit, but a Farmall M/Super M firing order is 1-3-4-2. Number one piston is located at the radiator side of the engine. Do you have an inline spark tester? It's also possible your timing marks are under paint, rust and dirt. To find them, I've had to severely clean the crank pulleys in the past. Also, have you been running it with or without the oil bath(?) air filter? Is the intake/exhaust manifold in good condition(good gaskets/no cracks/no broken bolts?) did you adjust the carburetor at all or set it to recommended spec(float height, needles, etc)?

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That's probably what mine is - this was several weeks ago now when I had done that and was going from memory on the actual firing order, but it was staring me in the face at the time :)

I have a test light to check power from ignition running to coil, and have checked the plugs individually firing, but have not utilized an actual inline tester. There were several notches in the crankshaft pulley, a couple of which were fairly close to lining up with what I felt was TDC using the screwdriver, but between the un-exactness there and not knowing for sure that I was looking at a timing mark on the pulley, hard to know what was what with 100% certainty. The thing is literally in the back yard of a house in a neighborhood with a little tiny driveway to snake around through. I've already got my pickup truck stuck once on a trip down there ($160 towing bill...), so it's just difficult to do much. In hindsight, maybe not such a great purchase...lol

Mostly have had the aircleaner tube off, and back of the carb exposed, so that can make sure the choke flap is operating, choke it manually by hand covering it, spraying starting fluid, etc. It does have the oil bath air cleaner assembly. I've tried it a little with it all plumbed back in also, but not as much.

Carb was rebuilt recently, float height is inline with what I've saw recommend here. I got a barb fitting and put in the drain **** plug and then ran a piece of clear hose up to the top edge of the bowl and looked at the height that way. Carb has a new gasket, new needle valve, new seat. I have adjusted the screws quite a bit with no change in its behavior, including adjusting while trying to crank it over. I started at the owner's manual recommended # of turns out for each one and then turned in and back out some more from there.

Intake has a new gasket where the carb bolts on. Have not had the intake off the engine. It has a helluva vacuum on the carb when you put your hand across the back of it, so don't think I'm losing any suction, but possibility. Have not looked at the exhaust manifold any.

 

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problem was in engine prior so cant rule out much internally

frustrating not being there...

being out in the bush....fancy back yard without a rudder   is hard to confirm 110% on issues

your restatements  leads to 2 "quick thoughts........ rich    too much fuel  timing fire weak off.

 

vacuum sounds good.....at any time have you  got excess fuel to run out carb snout? 

need helper ,cover carb 98% with hand  crank 20 sec  should have at least a handful of gas...vacuum/ carb acceptable to putt about

play with timing until backfire both ways then put in center irrespective of where it should be( have an engine 24* out,once we got the dealer service logs factory marks are wrong and it has to be that way???)

spark....td 9 run on SF every time )...did this for 3 hours till I swapped known "WORKING" parts  all checked good  but at cranking speed  points needed filed square and 1 plug 2 wires   caused late weak spark under pressure.....now runs if you get too close!

in '16 bid $500 on a rare find ,since everyone else was quoted $3k "recovery" ...... 2 ALL day wintertrips with everything but $1500 used pump  still no start .   then 3 week wait   borrow trailer  order winch   have mounts made for trailer  200' of chain /cable ,tackle,chain falls ,straps etc etc 4 batteries and means to keep charged  air compressor tools etc  took 6 hours to load...so must be an addiction

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7 hours ago, mmi said:

problem was in engine prior so cant rule out much internally

frustrating not being there...

being out in the bush....fancy back yard without a rudder   is hard to confirm 110% on issues

your restatements  leads to 2 "quick thoughts........ rich    too much fuel  timing fire weak off.

 

vacuum sounds good.....at any time have you  got excess fuel to run out carb snout? 

need helper ,cover carb 98% with hand  crank 20 sec  should have at least a handful of gas...vacuum/ carb acceptable to putt about

play with timing until backfire both ways then put in center irrespective of where it should be( have an engine 24* out,once we got the dealer service logs factory marks are wrong and it has to be that way???)

spark....td 9 run on SF every time )...did this for 3 hours till I swapped known "WORKING" parts  all checked good  but at cranking speed  points needed filed square and 1 plug 2 wires   caused late weak spark under pressure.....now runs if you get too close!

in '16 bid $500 on a rare find ,since everyone else was quoted $3k "recovery" ...... 2 ALL day wintertrips with everything but $1500 used pump  still no start .   then 3 week wait   borrow trailer  order winch   have mounts made for trailer  200' of chain /cable ,tackle,chain falls ,straps etc etc 4 batteries and means to keep charged  air compressor tools etc  took 6 hours to load...so must be an addiction

Yes - Dad has went down there on about 3 or 4 trips now and we've tag teamed the starting and fiddling with teh carb/ watching plugs fire, spraying ether, etc. Just the distance and travel is a little harder on him now with his age than it use to be. It was trifling hot when we first went down there, it's cooled down a little now. Definitely did get some gas on your hand when physically choking air cleaner side of the carb. This is when it would pop off and act like it was trying to fire, but would never stay running. Did this probably on 6-7 different occasions. 

I've told dad I wondered about weak ignition just because ether has such a lower flash point - maybe not good enough to light gas. Don't think I have anything else with a 2 wire coil I know is good but will do that and plug wires and double check the points again. We ran some 320grit sand paper through them and had them pretty clean, didn't look like it was rough or burnt up on the contact.

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frustrating ....!!this can be 1 or 3-4 little issues together

most any new part is such garbage  it has to be tested before install,several dealers have been checking electrical before hitting shelf with 40% bad then get dinged for restock

dist cap $50 I just purchased had a warranty (tested good but I didnt need) cant be returned for didnt need,I said my CC has defective item no pay,return it under warranty, toss it and lose your $25 cost,upper manager tested and agreed cheaper  return 

I would give it another hours try and then figure  how to load it dead

test them if you have to with ohm mtr  known good cap copper core wires new c-86 plugs

 file points with actual point file,  with at hand jumper wire from bat to coil  confirm good blue spark with shielded SN screwdriver (open close them)  use air cap tester to again confirm  flow points cap wires,  when good  squirt 1/2 oz oil into cyls and crank 20 sec  walk away 10 minutes  crank again,   have new plugs at hand   squirt 1 TBS of "NEW" gas into each cyl and firmly hand tighten plugs   add wires stand back and try with main gas off but carb full  and 1/2 choke   if good reaction  move on  but I would still suspect a years old underlying  timing /engine issue...? rotor is turning CW..?

strap your fresh gas supply tank up high  turn on    add gas to cys again  ,have some one crank and use your hand as a choke from 30-90% to keep it running,, get blade raised.....wheels pointed out   with good oil pressure find a throttle spot it will stay running adjust timing for best run

good luck    photos .....be safe.......

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have you pulled the distributer drive to see if the cam gear is loose on the shaft  that happened every once in a while on that engine.

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Have you verified timing by checking #1 cylinder is at TDC compression stroke ?  Both valves fully closed

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