Another Cub Won't Start CSC

ccaissie · Aug 13, 2011

Posted earlier, after 1959 cub rebuild, and after installing new carb, displays same symptoms.

Plugs get wet, after occasional sputters. Sometimes runs on a couple cylinders. Sometimes it runs well for a few seconds, i.e. hits on most cylinders. Mostly it floods.

Obviously, engine integrity is ok, and I get reliable spark when checking plugs.

I'm going to r&r the plugs, points, condenser. Had asked earlier if my cranking speed could be doing it (ignition on 6 volt, starter motor on 12), but cranking speed is under 1800rpm, so that doesn't make sense.

Help! This is going on too long!

El Toro · Aug 13, 2011

You probably should check your float setting to make sure there's no dirt under the needle valve and your float level isn't set too high. Recheck your valve setting to make they're set at .013"cold. Hal

JRSutton · Aug 13, 2011

You say occassionally floods - by that do you mean dripping gas?

To me it sounds like it's flooded the whole time.

I agree with eltoro to check the floats.

But if you just want to get it started before operating on it -

I would try turning the gas off completely. If it's dripping out the carb, let everything drip out for 10/15 minutes. Try starting occassionally in that time. Every time you crank it - if it was dripping, it'll probably make it drip some more.

Make sure it's fully choked.

Try one good attempt at the end of that 15 minutes. If it starts, be quick, or better yet have an assistant open up the gas right away, and push the choke in.

If it doesn't start at all, crack the gas open just a small amount, like 1/16th of a turn. And try starting a few times again.

That way you're using the shutoff valve to do the job your float's supposed to be doing.

And again, if it does start, open the gas right away.

This of course will only let you hear your tractor run finally (which is no small thing!). It will do nothing to solve your problem - but, it would prove it's just a flooding problem, and that playing with your floats isn't just a waste of time.

ccaissie · Aug 13, 2011

Old carb misbehaved, so rebuilt it. Same story. Thought it might be internal crack, defect. New carb now. Same ol' s***.

I'll try the fuel shutoff method. Or Starting ether, sparingly. It has run briefly, so I know the cam timing, valves etc., are ok.

Will recheck valve setting, but that ain't it, I believe.

Will get new plugs,points, etc., and reset the distributor.

Trying.

Jim in Ma. · Aug 13, 2011

When was the last time you cleaned the oil bath section of the air cleaner and the top section under the top screen, where it comes through the hood?

ccaissie · Aug 13, 2011

Not attached yet, but cleaned it out good during reassembly.

Right....what's causing it to suck so much fuel up? Or is the seemingly good spark not actually strong enough in the cylinder, and they get wet/

Trying. Wish it was a diesel. Gassers baffle me.

El Toro · Aug 13, 2011

Your coil may be getting weak. Look for a hot blue spark to your sparkplugs. Hal

ccaissie · Aug 13, 2011

OKAY. New carb behaves better, no major flooding, no wet plugs.

But won't run. Ether will give it a cough, but not running for more than a few seconds. New points, condenser, nice blue spark. Retimed it. Can advance and retard tming too far so will not cough.

Maybe not ENOUGH fuel now? Hate to disassemble the new (ebay) carburetor. Would like to check other options first.

Using 12V to run starter, 6V for ignition. Spins plenty fast. I don't crank it long enough to heat up the starter.

Any hints? Flummoxed.

Janicholson · Aug 13, 2011

#1 on TDC compression (forward cyliinder) Breaker points just breaking at TDC. Wires go:
2-1
4-3
Around the cap looking from back.
Jim

Challenger · Aug 13, 2011

Are you sure you have that firing order right? I think it is 1342. No. 1 is marked on the distributor cap and, as you say, the rotor turns around clockwise inside the cap as one faces the outside "top" of the cap.

Janicholson · Aug 13, 2011

It is 1342. My "picture" is accurate, top right #1 CW down to 3, left to 4, up to 2. seems
OK, Jim

Challenger · Aug 14, 2011

Jim,

I see what you are saying now. I had never seen the firing order set forth that way before. Your number display just threw me off. Thanks.

ccaissie · Aug 14, 2011

no, no. I've checked the firing order every time I pulled the plugs to dry them out, and routinely check them every time I do anything. A checklist for each attempt.

I appreciate your hints, but you're just stabbing at this, sort of like what I'm doing. The fact that it has run for several seconds reasonably smoothly...no belching thru carb, backfire, etc., is what screws me up. It rules out cam timing, head gasket, coil, points condenser, major stuff, etc. It's gotta be something or maybe a couple things at once.
I wish it would at least run crappy for a while so I can get some symptoms to go on.

Denny ('60 Lo-Boy) · Aug 14, 2011

Yesterday you said you were going to get new plugs, points, etc.......

Did you get these or not? Not knowing the history of your Cub from acquisition to now, I would give it a COMPLETE tuneup. All new plugs (Champion D-21 or equivalent), points, condenser, plug wires and distributor cap. Clean the new points at installation as they sometimes are shipped with a protective coating that can effect your spark.

I know you rebuilt the engine, but just for laughs do a compression check to rule out loss of compression somewhere (not likely, but CYA :roll: ).

ccaissie · Aug 14, 2011

It's the carb. No fuel flow through the needle valve. Took it apart, float drops and opens needle valve.Can blow air into inlet. Assembled, the float must hang up or something, because I cannot blow into inlet.

Starts and runs on ether, but not on gasoline. I put the old carb on, and it floods.

Am contacting the ebay seller of this new carb, and expect they will give me another.I could frig with it, but really should have a carburetor that works out of the box, after shelling out $239.

What a fustercluck.

Denny ('60 Lo-Boy) · Aug 14, 2011

It wouldn't run on the original carb, you rebuilt it and it still wouldn't run. You bought a rebuilt carb and it won't run. Tune it up while you wait on still another carb, you might be surprised.

ccaissie · Aug 14, 2011

Problem with the forum I guess. It sometimes won't post the entire contents of the thread. I stated there that I had done ignition work, and it runs.

First carb has internal crack and just dumps fuel. Second carb is a piece of s*** from ebay

Runs fine on ether, replaced ignition parts. Carb is junk.

ccaissie · Aug 14, 2011

Updated thread: new points/condenser, spark is still big and blue. Wires, cap rotor all nice. Expensive to just buy for the heck of it.

I once said that gasoline engines were trash, and in retaliation, the Gods of Octane have been vengeful. Or something.

Carb is junk. Cannot inlet fuel. Again, runs on ether, not on gasoline. Beware Ebay, I think, unless I get satisfaction from the seller.

Janicholson · Aug 15, 2011

an issue that may be important is the internal structure of the intake manifold. If it is cracked between the intake, and exhaust at the heat transfer box, it might have similar symptoms! Jim

mkirsch · Aug 15, 2011

It wouldn't alternately flood, then not suck any fuel at all, depending on the carburetor...

Frankly, I'm pretty sure you've got two carbs with sticky float problems. The old carb sticks open. The new carb sticks closed.

You can't expect a carburetor that was stuffed in a box with some newspaper, and thrown, kicked, and banged around for 1000 miles to be in working order when you get it. Sometimes it is, but usually the float gets bent and sticks. It's not unusual to have to take the carb apart and reset everything...

ih560 · Aug 15, 2011

(quoted from post at 13:18:29 08/15/11) It wouldn't alternately flood, then not suck any fuel at all, depending on the carburetor...

Frankly, I'm pretty sure you've got two carbs with sticky float problems. The old carb sticks open. The new carb sticks closed.

You can't expect a carburetor that was stuffed in a box with some newspaper, and thrown, kicked, and banged around for 1000 miles to be in working order when you get it. Sometimes it is, but usually the float gets bent and sticks. It's not unusual to have to take the carb apart and reset everything...

Exactly, people who have seen how carriers like UPS and FedEx handle packages wonder how anything ever arrives in one piece. I've seen football treated more gently.

I agree that it is more than likely a Float/Needle valve issue in both cases. There isn't a whole lot to go wrong inside of these carburetors if everything is clean.

Another Cub Won't Start CSC

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