Frustration

I spent over three hours today messing with the 300. I put the correct coil on it and have verified that I do have a blue spark which will jump a 1/4" gap on a spark plug. I took the carb apart again and checked the passages, the new carb top is cleaner than the old one from what I can see but I still cannot get it to fire. There are four holes on the hinge pin side of the venturi that I do not feel like I am getting completely clean, maybe, but I do not know where they go. I do have gas in the carb bowl, and I do have suction when I put my hand over the inlet. I got it to pop once by putting about a tablespoon of gas in one cylinder. The starter is turning the engine over at what I would call a normal speed and the battery is making good spark at the same time. I have plugged in the coolant heater for the night and tomorrow I will try again to figure it out. I do not have a compression tester, so I guess that could be the problem. I also have not checked the valves since I set them after putting the engine back together in the summer. It was running great when I was doing a small logging job for a week or so before Thanksgiving, but these last few weeks it has not been happy, and when the tractor ain't happy ain't nobody happy, as the saying goes.
Zach

Hello zack,
I had a 300, and it would not start if you had any throttle on.,also had to hold my hand over carb to get it started.
Make sure the dist hasn, cut a pin , the hydrolics put quite abit of pressure on it
Clif in ogdensburg
3157134115

If it is pulling a vacuum on your hand, it is going to have compression. If the spark is getting t the cylinders at TDC it is going to be assumed that the system is correct. Two things then stand in the way. one is fouled plugs. They might even look perfect, but need to be heated with a propane torch till the little ground electrode is very hot, and the plug smokes some. Put them in warm, with a rubber hose to keep your hands from getting toasty.
Use a squrt oil can with gasoline (2stroke is great) in it to put two pumps into each cylinder before the plugs go in. If it fails to keep running then it is some major plugup in the carb. Merry new year, and I hope this helps. Jim

Thank you very much, your advice is always much appreciated. I had heard of cleaning plugs with a propane torch but I never knew that they should be put in hot, and I have never done it at all. I cleaned them somewhat with sandpaper but I couldn't seem to get them squeaky clean. I will follow your directions tomorrow morning. Happy tomorrow and New Year.
Zach

Put say a table spoon full of ATF in each cylinder and then spin it over holding you hand on the carb ignition on. Do so and listen close to the engine for it to maybe try to start. It may well do so and if it does that says the compression is a tad bit low but the ATF may free up what is causing it to be low. A non starting tractor is why I have more then one that way no matter what at least one will run and if one will run then others will too even if I have to pull start the next one. Something else to try is a simple tarp and a light bulb close to the manifold

Thank you for the advice, it started pretty well when the temperature was warmer and once the engine has been running I can shut it off and it will start right back up again instantly, but something about cold starting seems to be hard for it. I have not heard of putting your hand over the intake, I imagine that would function rather like a choke plate but maybe better. The rotor does turn with the engine when I checked, I wondered about that too.
Zach

300"s are notorious for very very hard starting in the winter (cold weather). First tractor I restored was a 300...started great in the spring, summer and early fall. As soon as it got cold I could crank and crank on it and if I was really lucky, it would fire but if you werent ready to feather the choke, it would die and not fire again.

Complained to my parts guy who also restores them and he said to send the carb to him and he would take care it. Something about the jets being too small and need to be drilled out to a larger size. I dont remember for sure but after that I never had a single problem starting that tractor. Feel free to call him and talk to him about it.

Scott Puntam @ A.P. Equipment in Valley City, ND
1-800-400-2143

Zack I had a engine that the plugs looked good and I cleaned them and heated them and it still would not start. I put in a new set and it fired right up. I let the tractor warm up good and then put half of them in and it started and missed a little and then it smooth out and ran OK. then I replaced the other two and after that it started OK.

Bob

We had 300s dad and uncle were always pulling them for cold weather starts.

how about your air cleaner ?
it might be full of water and freezing and making it hard to start
sometimes its the simple stuff over looked
good luck

Thanks, I did check that but it is clean and I had the pipe off it anyway to check the suction on the carb inlet.
Zach

Thank you, I will give him a call if I can't get this to work.
Zach

(quoted from post at 22:50:50 12/31/12) Thank you for the advice, [b:807bad1431][i:807bad1431]it started pretty well when the temperature was warmer and once the engine has been running I can shut it off and it will start right back up again instantly, but something about cold starting seems to be hard for it[/i:807bad1431][/b:807bad1431]. I have not heard of putting your hand over the intake, I imagine that would function rather like a choke plate but maybe better. The rotor does turn with the engine when I checked, I wondered about that too.
Zach

Click to expand...

That is a very good description of how an updraft carburetor engine acts when the gas has had the most volatile parts evaporated off. The gasoline that is left will still run fine once the engine is running because the air moving past the idle port and venturi is moving fast enough to vaporize the fuel. At cranking the air speed is so slow that the fuel just dribbles out, and with the most easy to vaporize parts no longer in the mixture, remains as a liquid and is not drawn into the engine.

Fuel blended for summer use will also act the same way when the weather gets colder.

When my Super C and 2444 start to act like this I just give them a shot of Brake Clean before trying to start them. The Brake Clean vaporizes very quickly since that is what it is designed to do. Once started the engines run fine.

Adding enough fresh gasoline to have 10% - 20% mixture is usually enough to cure the problem until it also suffers from evaporation. About three months is the longest my tractors will go without adding fresh fuel before this problem starts to occur.

Thank you, that is interesting. I put gas in the tractor maybe a month ago, and that gas was probably bought in November as best I can recall.
Zach

Thank you all very much for your advice. I did what Janicholson said and it started right up and was happy. I plowed snow for 10 minutes or so and put it away again. I think I will try to plug it in the night before I intend to use it instead of just a few hours before, maybe that will help on future starts now that it is clean. Thank you Janicholson and all of you for your help.
Zach

Which thing did you do? Hand over the intake, or squirt gas?

Hand over the intake is just a one-time test, like a compression check. Just to see if you've got good suction. Use the choke for starting.

Squirting gas tells me that the tractor simply isn't getting enough fuel. You need a good rich shot of air/fuel mix at startup.

Any idea what your idle screw is set at? I can never remember whether in or out makes for more fuel.

I followed Janicholson's advice to put a little gas in each cylinder, heat up the plugs with a propane torch to clean them and put them in hot. I put the throttle most of the way to idle and the choke off and it fired right up this morning after also having the coolant heater plugged in all night. As soon as it started I put the choke on about halfway and left it on for a couple of minutes. I think he was right that the plugs were fouled and I had not gotten them clean enough before. I did put my hand over the inlet yesterday to check suction but today I had the air cleaner hose on. I set the main jet to 4.5 turns out and the idle screw 1 turn out as per the manual.
Zach

On occasion, I've gotten easier cold weather starts by disconnecting the oil-bath air cleaner.

You are welcome. The trick is often usable!
Many of the other ideas have merit as well. Have a splendid new year. Jim