International Cub won't start

[OrtisEvans]

I last ran it last fall and it worked fine. I tried to start it in January and no-go. The carb was flooding so I cleaned it an put in a new needle and seat. I checked the spark, which was weak, so I put in points, rotor, condenser, and cap. Still no go even with ether. I thought that I may have put in the distributor out of phase, so I checked it and that is fine. I checked compression and that is good. I thought maybe stink bugs had gotten in the exhaust and clogged it so I disconnected the pipe at the manifold. No help. Today, I pulled the plugs, laid them on the head with the wires connected and cranked to check spark. All are good. I checked timing again by putting a thumb on the #1 spark plug port, and yes, the spark occurred about when my thumb was pushed off. (I assume that the #1 cylinder is at the engine front - nearest the radiator, right?).

I am out of ideas. Suggestions?

Thanks
Ortis

 

[OrtisEvans]

I'm impressed - my post has 26 views but no answers! Either the answer is so obvious that everyone is laughing, or the problem is impossible. EIther way, I am in trouble!

 

[DJ54]

Yes, # 1 is at the front.

Did you get your wires back on in proper order? Rotation should be CW.

Even though you tried it on ether, did you check for fuel on the plugs?

With wires out 180ｺ, it would probably fire on exhaust anyway... POW..!!

This is a distributor, and not a magneto?

Hand cranking, or starter?

With proper timing, spark, and fuel, it should at least pop...

How far do you have the throttle set? If you do not have it set a little higher to run, than the starter is cranking it over, it may not start.

I have had better luck putting a little gas in the cylinder (half-dozen drops or so), directly in the cylinder. Maybe a couple of them...

 

[flusher]

I last ran it last fall and it worked fine. I tried to start it in January and no-go. The carb was flooding so I cleaned it an put in a new needle and seat. I checked the spark, which was weak, so I put in points, rotor, condenser, and cap. Still no go even with ether. I thought that I may have put in the distributor out of phase, so I checked it and that is fine. I checked compression and that is good. I thought maybe stink bugs had gotten in the exhaust and clogged it so I disconnected the pipe at the manifold. No help. Today, I pulled the plugs, laid them on the head with the wires connected and cranked to check spark. All are good. I checked timing again by putting a thumb on the #1 spark plug port, and yes, the spark occurred about when my thumb was pushed off. (I assume that the #1 cylinder is at the engine front - nearest the radiator, right?).

I am out of ideas. Suggestions?

Thanks
Ortis

I have a 1948 Cub that I'm working on--rebuilding the distributor/magneto.
You need fuel, air and spark to get that beasty running--you have the spark so it's got to be one or both of the other factors. I'd recheck your carb--if it's timed correctly and you're getting spark, it could be the carb--clogged jet would be my guess. To eliminate another fractor, I'd disconnect the air filter line to the carb and try to run it that way.

 

[Soundguy]

1, I would NEVER pull the dizzy to repalce points.. it's asking for trouble.

if it sat a long time.. might be stuck rings.. put some atf down the holes and let it set.. then roll it over the next day to expell the oil.. try again with start fluid.... once you get it started.. work it.

post back.

soundguy

 

[OrtisEvans]

Thanks for the ideas.
I am using the starter to crank it, and I do have the throttle wide open. Since I was using ether, have alwaysfound that having the trottle open gets the ether in better -especially since I am not relying on the carb when using ether.

I did have try disconnecting the air cleaner - no help.

I agree with Soundguy that pulling the distributor is not a great idea. The Cub does not give you much room to work, and I have pulled it several times and been fine. Since I have compression, I was thinking I don't have stuck rings, but a little atf can't hurt.

This tractor does not have a mag.

I'll also try a little gas in each cylinder - can't hurt.

I gotten a lot of engines working over the years, and I know that if you have fuel, spark, and compression they have to run - unless of course you have screwed something up - which has happened once or twice. I'll let you know what happens.
Thanks

 

[BobG_in_VA]

Hook another tractor to the cub and pull start it in 3rd gear. If its got compression/spark and fuel, sooner or later, it will heat itself up enough to fire...and you won't be ruining the starter or the battery to do it....BobG in VA

 

[wrench57]

You also may want to check that your float didn't stick in the carb after the rebuild. Sometimes a little tap on the side gets it to drop and work. Have had this happen before.

 

[Kiwi Farmall]

try another set of plugs,have had plugs short to the cylinder head through cracks in the insulator thus killing spark when installed but test ok when checking for spark.When you tried ether did the engine fire but not start or was there no response ,if spark was good it should have fired with ether and if it didnt i would say the issue still remains with spark or compression.If it did fire on ether then fuel would be the most likely fault .Also check that all the engine valves are opening and closing and not stuck .Have just read about a Farmall B on the farmall forum with spark issues where the condenser and /or wiring was shorting in the distributor,this would give a weak spark or no spark
Hope this may help

 

[OrtisEvans]

Update - I tried ATF in the cylinders. After purging, I tried again - I got a few nice puffs of black exhaust from the ATF (actually, I didn't have ATF and used hydraulic fluid). So, I will replace pugs on general principles, but now I am betting on some valve issue. Next step: pull the manifold and valve cover to see what is happening there.

Thanks for all the ideas.

On spark plugs - I have seen plugs where they are fould to where the spark jumps thru the ceramic right to the shell, but these are sparking right where the should be - even when covered in haydraulic fluid!

 

[Soundguy]

atf would have been better.. that's why we suggested it. it's high detergent.

you can clean the plugs


soundguy

 

[ptexer]

One time I had a similar situation. My cub has a pull ignition switch and it was bad. Your starter can turn and the switch will keep it from starting if bad. If you have a key switch could also be bad. Wire around these switches to check.

 

[Soundguy]

quick check with a jumper wire.. etc.

 

[tcreeley]

One time I crossed the wires. It popped but nothing more. Rechecked and started. When I used to crank it - what I did with the choke made the biggest difference, and how warm it was outside. I choked it. Got a pop unless it was flooded. Then I worked the choke back in until I found the spot where it ran. When it was warmed up, the choke went all the way in. That carb gums up often over the winter. Sometimes the glass bowl needs wiping out-. A clean carb is important. When added gas to the plugs - it was godd for one try, then they all needed drying and I'd start again. I suggest a battery- sears heavy duty 6v (they sell it for vans). Makes life easier. In the winter I used a magnetic block heater to keep it warm so it would start. When it floods, taking a walk helps! I replaced all of he electrical stuff, wires etc. when I put points in the magneto.
Good luck.

 

[ptexer]

one thing I did to help the flooding problem was to put a plastic shutoff right before the carb. If it floods just turn the shutoff to off and crank it should start then turn fuel back on.

 

[Soundguy]

hmm..

flooding is too much fuel from either too much choke or a bad float valve.

I'd adress those vs scabbing in extra stuf that is not needed.

besides.. there should be an oem fuel shutoff anyway.

soundguy

 

[ptexer]

I agree with you soundguy. Howeverthis is an old carb which I have to double gasket because of warpage of the carb top. I keep it inside my building and it is just easier to turn the added shutoff than the regular one under the tank. This keeps fuel from dripping on the floor.

 

[Soundguy]

true up that carb top with some fine paper and a true surface. also.. if adding a 2nd gasket that is throwing off your flaot setting.. that could be part of your issue. have you adjusted your float arm to allow for the extra gasket thickness?

soundguy

 

[tcreeley]

My carb was warped too. I used the rebuild gasket and an amount of gasket maker in a tube that came out gray. Gas resistant. I was careful to not overdo it so it wouldn't run to the inside. Squeeze the parts together so the gasket maker is contacting -then with a nail or something add more gasket maker along the outside edge all the way around. Makes it thicker and helps fill in where it is warped. Squeeze and assemble. Work fast.

I used it on the glass bowl too. I skimmed it along the edge of the glass bowl, thicker on the outside edge so when I pressed it up - the extra wouldn't run down the inside of the bowl. I had two small runs though which I ignored. I let everything dry for a day before adding gas. Never had a leak after that.

 

[Soundguy]

yikes! what a nighmare!!

IMHO.. a new//rebuilt sed bowl and carb just isn't that much money.

I'd only use that technique to get me home or out of a field.

say.. were you the maintenance re-engineer that took care of all my antique tractors before I bought them? sounds like it

good luck!


soundguy