18 Auto starts then quits

[buffcleb 2]

So after using our 18 auto last week and it running fine we headed down to the cabin this week and wanted to fine tune the PTO adjustment... thats when the fun started

 

This week the tractor would start, w/ choke, and run for 10 seconds or so then die.... until it died it sounded fine then just putter out... tried it without choke and that had no effect...

 

some of the stuff we have done :

 

1. We rebuilt the fuel pump a couple of weeks ago... its the original fuel pump... we replaced all the fuel lines and the fuel filter at the same time. The gas tank is also original...
2. We installed a new coil (the old one was leaking fluid but seemed to work) and re-gapped the points last week as well..
3. after scratching our heads we pulled the carb and cleaned it and adjusted the idle and main jets back to factory specs... the idle jet was set to 2 1/2 turns and the main jet was set to 4 1/4 turns before we set the idle to 1 1/4 and main to 2 turns... that might explain why the plugs were so black when we pulled them...
4. I check the compression on both cylinders and they were both around 95 - 100 psi...

 

Cleaning and adjusting the carb had no effect... it would still fire run for 10 seconds then quit...

 

So here are my thoughts... 

1. even with the fuel pump rebuild its not putting out enough pressure... I hooked up a mityvac to the fuel line and did not see much pressure...not the 4 PSI I think is needed... more like just 1 or 2 PSI... I also hooked the mityvac up to the crank case vacuum line and saw a strong pulsing...
2. The original gas tank is a bit rusty... I'm not sure if there is a filter in the gas tank that might not be allowing fuel to flow fast enough...

I'm thinking if replacing the fuel pump with an electric one... it might not be the problem but I figure it shouldn't hurt

 

I'm also thinking of pulling the gas tank and replacing it with a boat gas tank until I can clean and seal the current one... 

 

I'm thinking (doing way to much thinking ) that these will help but I want to hear others opinions... to me it seems like a fuel delivery problem... do others think this might be the case? if anyone has switched to an electric fuel pump I'd like to know which one... really any help would be appreciated 

 

thanks in advance...

 

 

 

 

[Trouty56 565]

I made a temporary tank out of a gatorade bottle and a tire valve.....drilled the gatorade cap and stuck the valve in it...pulled the center out of the valve.....I use that to eliminate any pre carb issues....

Just hold it up and let gravity  do its thing....

[pfrederi 17,672]

How long do you have to wait before it will restart??  Also hook up and in  line spark plug tester and see if you get spark as it stalls out.  That would pretty much nail it as fuel issue as you have thought.

[buffcleb 2]

we normally gave it a minute... but was not keeping track of it that closely...

 

I didn't have my spark plug tester down this weekend... I'll bring it down next weekend and try it out...

 

thanks

[buffcleb 2]

OK... an update... it might be long but its worth it...

 

So this week I brought down my two spark plug testers, a new electric fuel pump, an inline fuel pressure gauge and a new fuel filter and proceeded to test...

 

first test was the spark plug testers which showed that we indeed did have spark right up until it died...

 

So I next added the inline pressure gauge and with the mechanical pump it did not sure much pressure while starting... if I used some starting fluid it got about 3psi while it was firing...

 

I figured what the heck and installed the electric fuel pump... I'm pulling 12v from the coil so it comes on when the key is turned on... I installed this pump, Airtex E8016S Electric Fuel Pump and added the inline filter before the pump...

 

the pressure gauge showed 5psi... great... turned the key with great expectations... and... wait for it... the same... it was start sometimes and die...

 

so now I'm thinking WTF... I have spark... compression and fuel... or did I

 

I still had the feeling that I was not getting fuel... sounded like it was running out of gas... so I re-pulled the carb.... and checked the bowl... it had a little fuel in it... but not enough...

 

Thinking that there might be a filter on the inlet I pulled that and checked... no filter... but what did I see... a little white piece of plastic... flapping in the hole... 

 

You have to be kidding me... I have been scratching my head for over a week for a tiny speck of plastic... really...

 

So there you have it... the tractor now fires right up... and with the electric fuel pump no waiting for the system to prime...