She still didnt start

[Ric0126]

The '51 8n is still not starting. I have repalced the cap and rotor button, verified the firing order, made sure I have fire to all of the plugs and cleaned them (the plugs are new). I have gas to the carb and the breather tube disconnected from the canister so I can apply starter fluid for help. While turning the engine over the best I get is backfire through the carb and not even an attempt to start. Should I now proceed as if I have an intake valve stuck and if so what's the best procedure?

 

[JMOR]

What else has been changed since the last time it ran?

 

[Ric0126]

Well this was my Dad's tractor and has been in the barn since he passed four years ago. I brought it home to get it running. It started briefly with starting fluid before I did anything. Since the gas was vanished I cleaned the tank, rebuilt the carb, replaced the plugs, cap, condensor, rotor, sparkplug wires and coil. Since then it does not even attemp to start?

 

[JMOR]

I would do a compression check, since that would give an indication of both ring sealing (which will improve on second compression test where you first dump a couple of tablespoons of oil in the spark plug hole), and indicate stuck valves.

 

[Ric0126]

I did a shadetree compression test using my thumb while verifing the TDC for cylinder 1 when I was getting the firing order and making sure the cap and wires were correct. I had pressure on all cylinders then but will have to get a gauge and do a true test. Should I be looking for at least 90psi or so?

 

[Dell (WA)]

Ric......how many times have you been advised to do the dreaded compression test??? It really is NOT HARD and will quickly answer many of yer "issues".

Generally, ya hafft take the cylinder head off to access the valve. BUT without doing the compression test, you won't know WHICH valve is stuck. Understand??? ......respectfully, Dell

 

[Chuck (CA)]

"best I get is backfire through the carb"

Backfiring through the carb can also be an indication of timing being off. Use your thumb idea to check TDC for #1, pull off the cap and see where the rotor is facing; (might even be 180 degrees off)
HTH

 

[G6 at Snook, TX]

Ric,

I thought I asked you yesterday on your other thread if the distributor had been pulled or messed with. If so, you might have your ignition timing off. When my tractor would not start and exhibited the exact same symptoms as yours it was because I had knocked off the timing. Yours may be the same case, or it might not, but it is a question worth asking. And with a run of the mill sidemount it should be a breeze to set to the flywheel. Follow the I&T manual.

The compression test is easy to do as well. You will find out a lot there too.

 

[Jerry/MT]

Check the timing.

 

[Bruce (VA)]

Between yesterday & today, you've had about 6 of us now suggest that you check the timing. What's up w/ ignoring those suggestions?

If the distributor is loose or has sufficient wear, the timing will be off.....and it will backfire through the carb.

You're thumb isn't a very accurate compression gauge.
50 Tips

 

[ZANE]

Have you got the wires going clockwise or counterclockise????? It does make a lot of difference.

I doubt that compression is the problem if it ran before you "fixed" it.

Zane