Hard starting & cold blooded, What to do?

[John Niekamp]

Ok, another one of them ASKED OVER AND OVER again questions here, but I too am having the same EXACT problems as Cityofc described. What few suggestions I had to him, I have done myself, with no luck. I even gone back to that thread and re-read eveything once more.

Are there any other secrets on what to do to make this Cub of mine easier starting and less cold blooded?

Last Saturaday when it was warm, it didn't want to start very well after sitting for several months. I could understood this, but after I first got it started it ran just great. Now that it has gotton cold out again. IT DOES NOT want to start again and then when it finially started, I had to run the choke about 3/4 of the way closed and could not take it off completely.

I have new points, plugs (all adjusted correctly) and plug wires, battery and gas all new too. Carb. all rebuilt as well as the starter, with real good compression. Like I already said it ran just fine Sat, when it was 60, now that it's high 20's, it is doesn't. The engine spins over nice and fast and has a clean blue snappy spark at each one of the plugs.

I can't understand what is going on here. What did I NOT do or am I really missing something here? These Cubs aren't typically hard starting and cold blooded, are they?

Do I need a different gap on the points, hotter plugs or as suggested a week or two ago buy Cityofca a block heater? I've always said in the past that a well-tuned engine didn't really need one, but maybe I was WAY wrong.

I am really dissapointed and really don't know what to do next. Maybe I was just spolied from the way my 8N Ford staretd and ran in cold wx.

John Niekamp

[Rick ('50, NC)]

John,

I was having the same problem with mine until I cleaned all of the contacts on the starter, battery, and ground. As a matter of fact, I ran a ground cable directly from the ground strap bolt on the battery box to the frame to ensure good contact. It was amazing how much faster the starter turned that motor. I had just not noticed the gradual decrease in crankng speed until mine decided not to start on a cold morning.

Give it a try and good luck.

[beaconlight]

John I had the same trouble hard starting and keep the choke out in August. It was because of fine rust in the gas tank plugging the carb. Hard starting is one thing but having to keep it choked so long can only be lack of gas or excessive air leaks in the intake manifold, carb the gasket joining them, the sediment bowl plugged, the screen at the inlet to the carb or the gas not fully on at the shut off. As I see it it has to be gas related. Spark related is pushed far daown the list by the excessive choking for so long.

Bill

[Albie]

Hi John: I appreciate the answer you are given and include my own thought that if I have the straight heavy weight oil of the summer I always add a cup of kerosine to that oil for winter. Most likely I would have change to a straight wight LIGHT oil for winter so that the engine can turn over easier when cold. Thin oil, charged battery and tuned uo....cant miss. AlBie

[Lurker Carl]

If it starts and runs fine above freezing, but not below freezing, I would look for moisture in the tank, sediment bowl, fuel line or carburetor. Water 'shrinks' as the temperature drops to about 36 degrees, then expands until it freezes. You could have just enough water trapped in the fuel system that closes down the gas flow when temperatures drop.

[John Niekamp]

Well one other thought I thought about all day today at work was bad spark plug or plugs. I don't know if anyone else had ever had a plug that doesn't fire correctly under compression It sounds like a stupid theory, but I have had other plugs that would fire good out of the engine, but not do anything in the engine. I don't know what else to say or why, but you can take and put in another plug and it will run just fine. Prime example is a single cylinder lawn mower engine. The plug looks good and fires good, out of the engine, but still won't run once installed.

The reason I am wondering this is because again tonight I tried starting the engine and when it did finially somewhat run, it was missing on a couple of cylinders, they finially both picked up one by one.

These spark plugs wasn't purchased from IH, they were some cheap Chineese made ones that I purchased out at the local Farm and Home supply. The only reason I got them there, was the dealer was closed and I found some that was "supposed" to for a Cub. They aren't like a Champion or AC/Delco, just some funny sounding name that I have never heard of before. Should have known better they were way cheap in price.

I think that I will go to Case/IH Friday and get some good ones and hopefully that will fix this problem.

I just have this gut feeling it's in the ignition more than anything. What does anyone else think

Albie, I have considered this too, I am running 20 weight oil in the engine and the engine turns over at a good clip. I've heard the old timers talk about the kerosene (or actually coal oil, old timers again, lol) trick during the winter months. I guess it will just be the process of elimination. It's just so hard for me to belive how easy and well it runs in warmer wx. I would have laid odds that it would start with no trouble at all. Sure glad I didn't bet on it now.

John

[Eugene]

Been thinking about this one for several days. Ignition timing. I didn't see in the initial post that the engine was timed.

[John Niekamp]

Been thinking about this one for several days. Ignition timing. I didn't see in the initial post that the engine was timed.

Eugene,

Well you are right, I didn't mention that, earlier did I? Well I THINK I timed it correctly according to the pointer, but you know that is something that would be an easy check. The way I timed it, was with the engine running at 400 RPMs the mark and the pointer lined up on ZERO degrees on the pulley. My pulley only has the one mark and I assumed it was for a ZERO degree line.

Now you really have me wondering and second guessing myself on this one. Really something I didn't think about, to tell you the truth.

I'm not even 100 percent sure that ZERO degrees is correct at 400 RPM. I was thinking that at HIGH IDLE is around 1200 RPM is around 14 degress BTDC. I don't know how else to check it but at the ZERO mark, I don't have enough room or a way to mount my degree wheel on this engine. BUT I do know the exact engine speed. Well that is if my digital testing tach is correct, lol. So if you can give me some more input on what engine speed verses this little pulley mark, it would be greatly appreciated. If I was smart when I had the front end off I would have made an adpater for my degree wheel, but that's hind sight. I would surely think the mark on the pulley would get me very close.

My thoughts are MAYBE these should be timed on the HIGH IDLE side, for the best performance. It could be after tthinking about it timed to far in advanced. BUT if this was the case, wouldn't it be kicking back on the starter by predetonating

John

[Lurker Carl]

If your Cub is timed at 0 degrees at 400 rpm - she should start and run. Advanced timing will kick back, retarded timing has no power. You may have several problems that keep the Cub from running in cold weather.

Replace your brand X plugs with a name you recognize. Make sure the new wires are copper core, not the modern kind designed for HEI and computerized engines (too much resistance). A bright blue spark that jumps at least 1/4" should not 'blow out' under compression in a charged cylinder.

If an engine won't run (at operating temperture) without the choke engaged, there is too little fuel or too much air. Air is more dense when cold, therefore the fuel to air ratio changes as the temps drop. Also, gasoline is less volitile when cold. If your Cub's fuel to air ratio is marginal at 70 degrees, as the temps drop you get more air, thus you need the choke to reduce the air input to get the fuel to air ratio back close enough for the engine to run. A weakness in the ignition system will exaggerate this problem but fixing an ignition problem will not solve it. You need to look for air leaks or fuel blockages or both.

[John Niekamp]

Lurker Carl,

THANKS, I just got back down here in the basement after going out to Case/IH and getting a set of Champion" plugs. That helped out some, but like you said did not completely fix the problem. (at least this time, all four cylinders were hitting) BTW, yes I do have copper wires and not the graphite ones.

I didn't really have the time tonight, to let it get all the way up to operating temp. (I was getting cold) but after several minutes, I was able to take the choke completely off.

Now this is something else I did discover.

With the throttle lever at 1/3 to 1/2 half way up, it will not start. BUT if you take the throttle and move it completely down to the slowest possible idle, it starts just fine., but in order to run it up to full throttle, you have to ever so slowly take it to full throttle.

What this reminds me of, is an old carburetor. with a bad accelerator pump, when you would stomp on the gas pedal, the engine falls on it face, but you can slowly ease into it. My Cub is acting the exact same way.

Now this leads me to believe (again, like you have said) that the carburetor. needs something done to it, can this be adjusted out by the air mixture screw then ?????? At 70 degrees, I did not see a problem, or if there was, it was not noticeable enough for me to detect.

When I first got the Cub, the P.O. took the carburetor apart and instead of using regular gasket, they used silicone between the top and bottom half of the carburetor, well you know as well as me how well gas and silicone gets along.

Well after soaking the carburetor for several hours in an industrial strength carburetor dip tank, and cleaning by blowing everything out wiht a needle blow gun and visually checking everything over, I am convinced that I got it all out of the passageways, but there could still be one small piece that I overlooked that could be causing all of these problems.

If there is some other way that you know how to "time" the engine, from the way I did it please let me know. I only have the one timming mark on my pulley and I even check that out again tonight by marking it with a yellow paint sitck, just to make sure and there is still only one.

Again that was at 400 RPM on that pointer and mark. The only other thing I have not checked in the ignition is the DWELL, but I think since the points are adjusted correctly, this shouldn't be a real problem, OR should it?

John

[mike mix]

The first thing to always check on hard starting in cold weather is the fuel. Gas companies have summer and winter blends of fuel to help starting in cold weather and to keep fuel from vapor locking in the summer. All of the problems you mention with your cub sound like old summer blend fuel in the tank. To properly trouble shoot this problem make sure the fuel you have in the tank is fresh winter blend fuel.
Good luck Mike

[Lurker Carl]

As long as the timing is at 0 degrees at 400 RPMs, don't fret over the ignition system until you get the air/fuel problem solved. Silicone is evil stuff once it gets loose inside the carb because nothing actually dissolves it but will make to gooey enough to work loose and stick somewhere else.

You have to start at the tank and work your way to the manifold. Something is restricting fuel flow or letting too much air in. So start at the beginning, assume nothing and check everything. If possible, get the tractor above 32 degrees so any ice in the system will melt and the resulting water can be flushed out.

Look inside the tank, is any debris clogging the sediment bowl inlet? Clean the sediment bowl and brass filter screen. Disconnect the fuel line at both ends and blow it out. With the petcock under the tank opened, open the drain on the bottom of the carb and have a can ready to catch gasoline. If you don't get a steady stream of gasoline pouring out for at least one minute, then look for a clog in the fuel screen where the fuel line enters the carb. Make sure the bowl vent is clear. Also check that the float is not hanging up against the bowl. When the float drops, does the needle valve actually drop open? Is something blocking the opening in the cage to keep fuel from flowing?

The main jet, the hex plug on the side of the carb, should have 2 holes in it. One goes thru the side of the shaft and the other goes right down the center of it. Make sure BOTH passages are clear, use a toothpick to poke out any debris. Also check the discharge nozzle for clogs.

Check the idle circuit, there may be debris or even the bowl gasket restricting the ports. Look for a warped throttle body where it meets the bowl casting AND the manifold, the main source of air leaks.

Rudi has this and more posted at http://www.cleancomputes.com/Cub/Maintenance%20Tips%20and%20Techniques/Lurker%20Carl's%20Cub%20Carb%20Fixes/index.html

Be methodical and thorough with your troubleshooting, recheck all the settings and clear ALL passages with compressed air and toothpicks.

Good luck and may the force be with you.

[beaconlight]

I find even better than tooth picks one of the wires from inside telephone wire or cable. It is small enough and will not break off if you are too vigerous.

Bill

[cublo]

My Cub just wouldn't start in the cold. I replaced the plugs, got better spark. Changed oil to 10 weight. Had slow trickle of fuel from strainer to carb pipe. Blew out the line from carb up into tank (removed gas cap and placed rag over filler hole). Fast fuel flow, still no easy start, although more signs of life. Opened idle mixture screw a bit, cleaned out high speed jet or tube (correct term?). It started nicely every cold day after that. Then one day, no start!!!! It turned out that the choke pullout rod was not turning the choke butterfly. It was slipping on the shaft. It took me a while to notice that the choke arm wasn't moving when the rod was pulled. Fixed that, and man does cubbie start mighty quickly on a 7 degree morning! Keep on looking, you will find the solution. Hal in CT

[John Niekamp]

Luker Carl,

I have heard that these carburetors can't be somewhat picky, but as with any carburetor, being clean is crucial. I even may have to think about sending it to a PRO. My top half was a little warped, (as most are) and that was probably the reason they used silicon in the first place. I pressed here and there and got it flat again, then I put in the new kit.

The tank is clean as can be, as well as the sediment bowl too. However I never checked the flow of gas out of the fuel line, so this will be where I shall start at. When I had the tractor torn apart last year, the tank had some varnish and some light rust. I first media blasted out the entire inside of the tank, even got behind the baffle, (spent about 6 hours on it) vacuumed it out, then hot steam power washed and then I inspected the inside of the tank with a flex optical light scope. then the last thing "Red-Kote" was applied. Just looking inside the tank now, there is no signs of debris or crap floating around, everything looks nice and clean, nothing in the sediment bowl or filter screen. (a good sign to me that the tank is well cleaned)

I just went by the rebuild kit instructions for setting the float, but your illustrations makes a WHOLE lot more sense and for a lot more accurate too. Hopefully this weekend if the temps are somewhat warmer and I will tear into the carburetor again. My guess is a piece of that stupid silicon came loose and is causing this whole problem.

I will just drain out the entire tank and put in all brand new gas. My 5 gallon gas can was filled maybe couple of months ago, so may I have some of the summer gas as Mike M. was referring to. It sure won't hurt anything, I 'll just drain the gas, and put in the old 54, it's not picky on what it burns,

I even had one gentleman from here on the forum, sent me an email and offered to send me one of his good carburetors and try it out, but I just hate the thought of something might happen to his in the shipping process.

Thank you SO MUCH for your help, I'll let you know what I find out.

John

PS: From the sounds of it, you are the PRO on these things, do you rebuild them for other people?

Also thank you beaconlight and cublo, I have servel sizes of piano wires or stings of you will, that I have used in the past for getting into them little holes. This probelm I WILL overcome. I gots WAY to much time and money stuck in it to give on it now, AND with all this EXPERT help, how could I not