TO30 Losing Power.. Puzzling

[Kevin Godshall]

'53 TO30
12V Neg Ground

Been running tractor right along this year: plowing snow in winter, plowing garden in spring, running brush hog in summer.

During brush hogging, tractor seemed to be wanting in the power department, but I chalked it up to extra high, extra thick grass. Took half cuts and got the job finished without any thought to it.

Time to start pulling logs, but now tractor doesn't seem to want to run. Starts right off the bat, idles fine, but as soon as I put it into gear, we get into trouble. If I try to drive out the driveway in 2nd gear, it coughs and sputters and finally dies. When I took it downhill, it was surging and rough. Couldn't climb the back hill to the garage in 2nd gear, so I backed down to the bottom. Pulled the air intake off of the carb and restarted her. Idling rough now. Reattached the air intake and no difference. Tried pulling the choke out as she was struggling and she died.

After a few minutes of contemplation (mostly off color language), I restarted her and got her up the hill in 1st gear. (Not pretty, but she made it).

So........ here's what I did so far: First, removed the sediment bowl, and then replaced it because it was leaking and gunky. Flushed the gas tank and fuel line and re-connected it.

Second, disassembled the carb and fully cleaned it. Made sure float was right and main jet was clean. Reassembled and reinstalled, adjusting to specs in manual. (Main jet and idling air).

No success.

Third, pulled plugs and inspected. All looked good, not fouled or burnt. Re-gapped and reinstalled.

Fourth, pulled the valve cover and inspected the springs and rods. All looks good and seems to be working fine.

Fired it up and it idled fine. Wife came out celebrating the success. I backed it up about 100 ft and it wasn't horrible, (slight upcline), then I shifted into 2nd and it began choking. Made it back about 50 ft before she died.

Seems like when she is cold, she idles best. But as soon as I put her into gear, especially 2nd or higher, it's all over.

Exhaust looks clear (not overly black or white). All gas is new and clean. No backfiring.

I played a bit with the throttle rod and governor, but I'm now thinking (after reading some posts here), maybe I need to look at coil and distributor? Manual not helping me much on the 12V conversion, so I'm back to the experts for help.

Thanks.

 

[jon corbett]

u say 12volt conversion.when?was the 6volt coil changed out?points could b fried also.check inside of distributer cap for moisture,rotor for corrosion.

 

[Bruce(OR)]

12V conversion. How many volts to the points?
Since you cleaned the 3 filters in the system,
AND the fuel cap IS venting. I would have to gander the points condition and gap.
Weak coil?

 

[Charles in Aus.]

Sucking air through a faulty manifold gasket opening
up when hot?

 

[Jerry/MT]

Check your spark as soon as it starts running ragged on you. I mean right now!( Needs to be FAT AND BLUISH-WHITE, the color of lightning.) if it"s not good, then check the primary igntion circuit (battery through the key switch to the coil to the distributor to ground) because that"s where the problem usually lies. Yu have a 12v systemnm and theat"s non-OEM. One of theproblems with them is that some folks put a current limiting resisitor on the old OEM 6V coil(1.6 ohms) to limit the current through the circuit. And some folks don"t. So the coil gets overheated, the points burn or pit from trying to switch too much current. So check your coil.If it is ~3.2 ohms in primary resisitance, then it correct for a 12v system. make sure you don"t have an additional resisitor in the cirucuit. Some guys mistakenly put them in and they have the opposite effect. Key switches sometimes get high resistance and cause low current in an otherwise good primary circuit. jump around the keyswitch andsee if that cures the problem. OEM distributors have a lot bushing wear after 50+ years of operation and they can affect the dwell especially at higher speed. To check for bushing wear, rotate the engine til the points close and then push radially (from the side) on the distribitor shaft watching the points.Do this from several directions, watching the points. They should not move. Check the timing and advance also.
If your spark is good(FAT AND BLUISH-WHITE)
then open the plug on the bottom of the carb and verify you have adequate fuel flow to the carb. The fuel flow should gush out CONTINUOUSLY. If it dribbles or is intermittent, then suspect a blockage in the fuel delivery system. Check the filter in the sediment bowl, the "secret filter" in the fuel connection at the carb. Check th efuel line for a kink. If you find no blockage ther, then the float valve may have a clog or the float is "hanging up". Rap the side of the carb with a block of wood and see if that makes a change. The M-S carbs are sensitive to float setting so really make sure that you have the correct.
How does the engine accelerate from low idle to high idle? is th emain jet set correctly and are all the main nozzle passages clear?

Do these checks and you find the problem is either with a weak spark or poor fuel mixture. Avoid the tempation to throw parts at the problem and do the home work first. you"ll find the problem and you"ll learn something in the process.

 

[Gearhead210]

Sounds like the ignition coil is bad- A coil can work good when it is nice and cool, but a broken wire inside can lose connection after things warm up and expand a little.... Definately check for spark as soon as it does it, and do it right from the main wire coming out of the coil- not a plug wire. That will help narrow it down a little more (bypasses the cap, rotor, extra wire).

 

[2tractors]

Try a partial choke, if it runs better then it's probably fuel clog.

 

[Kevin Godshall]

Thanks to all for the input. Gonna get working on tractor here shortly and will report back later.

To update some of the things I have tried and forgot to list:

I removed the drain plug on bottom of carb and it runs out steady and hard.

Partial choke, or any choke, kills it immediately.

Inside of distributor cap was clean and dry.

When I start it cold, idle is fine at every rpm. Nice and steady, no surging. Engine revs in good response to increased throttle. Problems come up when I put it in gear and put load on engine.

Will troubleshoot the plugs, coil and distributor and report back results or progress.

Thanks again!!

 

[John (UK)]

If as you say it seems to run better when cold but fails when it gets warm then it will almost certainly be an electrical fault, Change the Condenser for a start as that is cheapest and they should be changed quite often anyway.Condensers often show up faulty as they create a spike or hole in the points.
If that doesn't work see if you can borrow a coil and try that. Usually a Condenser will fail in about 5 -10 mins after start up as it will get hot a coil usually takes longer but it is not impossible for it to be the coil. Fuel problems would usually show up sooner than 10 mins. What coil do you have, I see you are 12v neg ground if you have the original coil it was 6 volts and would require a resistor to drop the voltage, if it is a 12 volt coil it wouldn't. Has it by any chance got a resistor fitted when it shouldn't have one..If you need more info or help, email [email protected]

 

[Anonymous-0]

Check the cap and rotor well. I changed to a "high" output coil and the cap and rotor couldn't handle the power, burned holes through them.

 

[2tractors]

Kevin,It's obvious your pretty good from your diognostics,if all else fails do a compression test and then swap out the fuel in case water got in. Sounds like she died in her sleep.

 

[Mark from the Fort]

I'd be looking at the coil and/or condensor.
HOWEVER, I used to fight with my old girls about once every summer doing a similar thing.

I soon learned that the fuel pick up tubes (on top of the sediment bulb--sticking up into gas tank) would fill up with "crap" about once a summer.

The fuel would soak through enough over night to fire her up and idle just fine, HOWEVER, when I decided to put her into gear and throttle her up, she would soon drink more than was making it through the "crap".
I pop them off and twist a small drill bit (with my fingers) into each one and blow out with compressed air.
Another issue I often have is letting the fuel get too low. A "fuller" tank seems to push the gravity system a bit better.
Mark

 

[Kevin Godshall]

Update:
Turned into a "Honey-Do" day yesterday, and I wasn"t able to do much work on the tractor. Did stop by the store and pick up a new condenser though.

Installed it this am, and tractor started, but idled very slow, no response to throttle, and belching black smoke. After a few minutes, it shut down.

While I was pulling the old condenser out, the springs from the points had unhooked as well. There was 1 silver metal one and 1 thin copper one. Since I didn't see where they originally had come from, I hooked them both up together, with the spade of the new condenser with them. Checking in the manual, I can"t really tell if this is right. I tried to move the copper one behind the rubber insulator, but it didn"t seem to want to go, and I didn"t want to break it.

I put it all back together again, and hooked up a spare plug to one of the spark plug wires. No spark.

I re-installed the old condenser. No spark.

So, I have something screwed up. Hopefully I didn"t burn up the new condenser in the process.

 

[Kevin Godshall]

Finally got my voltage tester back from my father, so now have some numbers to report.

Owned this tractor for 5 years and never had to do much electrical work on it. Whoever owned it before and converted it..... well..... it's interesting. Maybe needs a full re-wiring this winter, but for now, just want to get it back to running to finish up the firewood and end of summer chores.

Anyway, here goes. Battery is a bit weak, I'm assuming is from all the cranking yesterday. Have the trickle charge on it now.

Battery
Key off 10.5V
Key on 9.5V

At key switch: 9.3V

Bottom of key switch are 2 wires. One goes to the generator, and the other to a resistor mounted on the dash

Top of resistor: 8.9V
Bottom of resistor: 4.5V

Resistor to coil: 4.3V
Coil to Distributor: (small wire that attaches to the points and condenser inside) .2V (this IS with the key on)

Does the engine need to be cranking in order for the coil output to be higher?

Let me know of other readings I need to take. Will try to do my best and report back.

Thanks again!

 

[Kevin Godshall]

A big THANK YOU to all who offered their expertise and opinions and advise on my problem.

An extremely big [b:3d9e7f6589]THANK YOU[/b:3d9e7f6589] to JohnUK for his persistence in emailing and sending me documentation specific to my tractor and my problem.

Update: Changed out the condenser and points, and decided to do the coil as well, since my 12V conversion was still running the original 6V coil with resistor. After a bit of fine tuning on the points, I was checking the spark by holding the plug against the frame of the tractor, and she started off on only 3 cylinders.

I did a bit more work on the fuel delivery system to make sure it was flowing well and wouldn't be problematic down the road: blowing out filter, gasket/bowl on shutoff, etc.

Since she's been running, I've hauled 7 heavy loads of firewood out of the woods, and she's running like a dream.

Thanks again to all for contributing here. There is definitely a wealth of knowledge and individuals willing to share it.

I can't say enough good about JohnUK. He patiently walked me through step by step, and taught me a lot along the way. Thanks John!