D15 not starting - banging head against wall

TitanTn

New User
I"m struggling here. It started with a simple tune up since it hasn"t had one in years and there was a little miss every now and then. Now I can"t get it to start at all.

New parts: plugs, wires, cap, rotor, points, condenser, coil, new to me carb.

I seem to be getting great spark at each plug, and the engine passes the finger compression check. Sucks and blows hard.

The carb float has been set. Fuel is flowing easily into the carb. After attempting to crank for a few seconds and no starting, the fuel dumps back out of the carb air intake. The plugs don"t seem to look very wet at all.

The part that confuses me the most is that spraying ether in the intake doesn"t make any difference.

Every now and then the engine will catch and try to start but it doesn"t.
 
Seems to have good spark as in blue/white in color and jumps a 1/4 inch gap or more?? If you can not answer yes and at all four plug wires check that first.
Gas coming out the air intake tube is not good and says it is flooding. So plugs maybe gas fouled and need cleaned. Learned years ago if it isn't broke do not fix it or it will be broke. I also NEVER replace condenser since you stand a 50/50 chance the new one is bad right out of the box
 
I will bet you are 1/4 out of time. Move each plug wire 1 hole , it will either run or backfire if it backfires move them back the oposite way 2 holes.
 
Time to start over with the timing first. Turning the engine over by hand make sure you are on the compression stroke on number one spark plug hole. (closest to the radiator) When on top dead center at the flywheel inspection hole, Make sure the rotor under the distributor cap is pointing to number one wire terminal. Loosen the distributor at the base and rotate back and forth with power on watching for spark. At this point set the distributor so the points are just ready to open.
If your firing order is 1243 it should start if it has fuel. To make sure that it is not have a fuel blockage if it doesn't start shoot a puff of starting fluid into the carburetor.
 
This is a great explanation and very easy to follow. I"ve confirmed TDC and the rotor is pointing to number 1. I adjusted the distributor as you explained.

Still no go. It tries to catch every now and then but it won"t. ether makes no difference.
 
If you have a good blue spark then it is time to get into the fuel system. Like I said before, try puffing some starting fluid into the carburetor.

You might check to see if you forgot the venturi when you assembled the carburetor. Without that it will not have enough vacuum to pull fuel out of the little feed tube in the neck of the carburetor.
 
I've gone through the carb several times. I've never professed to be a carb master technician, but I'm feeling pretty comfortable with this one by now. The venturi is in place. I am a little suspicious that the fuel is not being sucked up through the intake manifold. The plugs are not really wet at all. But spraying ether in the carb or in the plug holes doesn't make any difference at all.

So confused.
 
Put you hand over the carburetor when cranking it over at full cranking speed. or remove the carburetor and see how much vacuum you have at the manifold. If it trys to suck your hand into the manifold you have enough vacuum to start the tractor. When you cleaned the carburetor did you remove the power jet seat and the discharge tube?

If all of this checks out I would get back to top dead center on number one cylinder and remove the valve cover and make sure both rocker arms are up so you can get a .010 feeler gage on top of both the intake and exhaust valves for number one cylinder.
 
If the tractor will not fire when you spray ether or gas directly into the cylinders you just about have to have a spark/timing problem. Out of curiousity have you tried putting any of the old parts back in? As Old stated some things are better left alone. I have had new parts be bad directly out of the box. If you have not already done so, I would put the old condenser and plugs back in and see if that improves anything. What brand were your old spark plugs? AC Delcos are a resistor type plug that are not recommended for a points ignition system, you need a non resistor plug. I have personally had it where resistor plugs would spark enough to keep the plug dry but not enough to properly ingite the fuel, I changed to a nonresistor plug and the engine fired right up. Both were new sets but only one agreed with the engine.
 
When placing my hand on the carb intake, it's sucking fairly hard.

I did remove the discharge tube, and basically everything that could be removed. The only one I couldn't get out is the jet at the very bottom of the carb. But I sprayed carb cleaner through that jet and it very significantly blew out through the discharge tube.

I guess I'm onto pulling the valve cover.
 
I don't have any of the old parts. I wish I did.

I am actually running AC Delcos. There is another post in this string that recommended Champion plugs I think. I'll get some different plugs today and see if it makes a difference.
 
The bottom or main jet may be plugged even though you passed air thru it,if it cant be removed try to pass a wire thru it then some cleaner and compressed air to see if it is clear,they can be tough,good luck w it
 
Have an early model D15 that drove me nuts once. Its been a good while back but seems like the problem was in the ignition switch. It would run fine(with a little miss)and would die all of a sudden for no apparent reason.Other times it wouldn"t crank. It won"t crank if its flooded either unless you leave the fuel off an have a strong battery and can crank long enough to get the fuel level to a running heighth. Sometimes the float valve works and sometimes it doesn"t so I have learned to close the fuel valve after getting off tractor. Hope ur able to find the problem soon.
 
Well, I pulled the valve cover and everything looked good. Long story short, I've found at least half of the problem. I did not crush the spark plug "washers" enough. So they weren't grounding good. After real tightening them, I got the engine to catch and even run for a few seconds. I'm at a point now where I feel encouraged because the engine is catching and attempting to run. But it's still not running. I've got new plugs, and they're finally getting wet, so I know fuel is getting there. I've been adjusting the timing with the distributor, but it's not having a consistent effect.
 
Check the little square shaped black bakelight insulator, that carries the point wire through the outer wall of the distributor. Also check the point clip, that attaches to the inside of this bolt. easy to get an intermittent ground thataway. Also can be the key switch, if the key is loose, or has a heavy weight of other keys on it, can cause or mask the problem.
 
With the valve cover off you did check both intake and exhaust valves on number one for lash? (the distance between the rocker arm and valve end) with it on TDC? (both rocker arms up)

Any engine with compression, fuel being delivered, sparking at the proper time will run.

Top dead center marks on a fly wheel will show twice for number one. One time both rocker arms will be up the next time one will be down. If one is down you would be 180° off.

The other thing is spotting the FIRE line on the flywheel instead the TDC or CENTER line which would be 30° off on timing.

This is why I ask you to remove the valve cover and check valve lash

If both rocker arms are up and you use the timing instructions I gave first it will run if fuel is getting in the cylinders. If you can turn the distributor as is and get it to run some I would suspect the advance mechanism under the plate the points are mounted on has a problem.

Reading your posts it seems you have ruled out low vacuum to the carburetor and well as not having a good spark. Not running when using starting fluid points back to (timing) when you have a good spark and good compression.

.
 
Did you try to pull start it? Maybe the cylinders are washed down with gas and ether from trying to start it. It would get more voltage to the coil by not cranking the starter.
 
Thanks to everyone. It is running. Ultimately I think it was several things, but the biggest issue was the points. I think they've been burnt several times through out this rebuild process. I took the distributor completely apart and cleaned out the advance mechanism and oiled it up good. Cleaned the points and put everything back together. It started and with a little adjustment on the dist. timing, it was running great. I've got some adjustments to do on the carb, but I'm thrilled it's running.

Thanks again for all the help.
 

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