Too tired?

[OakhamMike]

I've been using my NAA now 22 yrs. for brush hogging, haying,and hauling a half dozen acres.Ive noticed it getting tired over the last few years.Hard starting, warm or cold, has been driving me crazy.I have all the manuals,I've set the timing, rebuilt the carb numerous times. I just installed a pertronix 6 volt neg.ground to eliminate the points question. All my connections are clean,new battery,plugs,fuel. Great spark,good fuel flow. It just cranks over and over without even a fart. I stripped it down a couple days ago and put on a new head gasket and the electronic ignition. I choked it and cranked it and moved the distributor all at once and got it to fire. I let it run for ten min. to warm up,moved distributor to were it ran best, then shut it off. Now it won't start. A compression check before the head gasket revealed approx. 80/85 psi. My question is: would this low compression cause my starting problem. P.S. at one point it almost wanted to start and I covered the carb completely with my hand and it started instantly. I haven't been able to replicate this since I shut it off.

 

[showcrop]

Mike you need to do a little less replacing parts and more trouble shooting. Yes, those compression numbers would cause lack of power and hard start. If two are low and two others are 20 or more lbs higher a new head gasket could fix it. but if they are all down 80 you most likely need new rings and a head gasket won't help. Wet and dry test will assess valves. You need to assess spark. A spark tester is best but you can also do it by removing a plug and grounding it against the block while cranking. Starting with your hand over the intake is indicative of not getting gas to the cylinders. Remove a plug or two after cranking with it choked to see if they have any gas on them. How have you been checking spark and fuel flow?

 

[OakhamMike]

Thanks showcrop,I've been checking spark with a visual checker, and the spark is nice, that's what I can't believe. Not a pop after long cranking with choke on. I thought, does it not have the vacuum to get fuel? Last fall I noticed a small head gasket leak at the rear,that's when I decided to do the head gasket and electronic ignition. All four cylinders are 80 to 86 psi. I pulled the head and found the cylinders mirror polished with a measurement of 3.431 (standard?). The three rear pistons have a 4 stamped in them. I was impressed with the brighter spark than the points. This old dog has served me well the last couple decades, so it's time to overhaul.

 

[showcrop]

(quoted from post at 18:55:02 03/22/20) Thanks showcrop,I've been checking spark with a visual checker, and the spark is nice, that's what I can't believe. Not a pop after long cranking with choke on. I thought, does it not have the vacuum to get fuel? Last fall I noticed a small head gasket leak at the rear,that's when I decided to do the head gasket and electronic ignition. All four cylinders are 80 to 86 psi. I pulled the head and found the cylinders mirror polished with a measurement of 3.431 (standard?). The three rear pistons have a 4 stamped in them. I was impressed with the brighter spark than the points. This old dog has served me well the last couple decades, so it's time to overhaul.

How about gas on the plugs as I asked you??

 

[cdmn]

Does a little squirt of starting fluid work? Are you drawing too many amps at the starter to
allow enough juice to get to the coil? Have you got a volt-ammeter? Are your battery and cable connections in good condition? Do you know someone you can borrow some "known-to-be-good" parts from, such as coil, carb, starter?

 

[OakhamMike]

No, the plugs don't get wet,I'm thinking it's just not getting fuel. I've swapped carbs,both work perfectly when it's roll started. It runs but can't be pull starting all the time. I'm looking at the overhaul kits now.

 

[showcrop]

(quoted from post at 15:01:33 03/23/20) No, the plugs don't get wet,I'm thinking it's just not getting fuel. I've swapped carbs,both work perfectly when it's roll started. It runs but can't be pull starting all the time. I'm looking at the overhaul kits now.

So maybe all it needs as some gas as opposed to a complete rebuild. The fact that it started with your hand over the intake verifies this. It sounds like your float level is low. How high is the gas level when you replace the float bowl drain plug with a barbed fitting and clear vinyl tube???

 

[OakhamMike]

Starting fluid don't work. I'm going to check the maps at the starter. It definitely doesn't crank that fast.

 

[OakhamMike]

Amps.

 

[OakhamMike]

I check that level with clear tube,thanks