First, I have rebuit the radiator, new carb (not rebuilt) new plugs and plug wires, distrubuter cap, all rubber hoses, fuel pump motor rebuilt with 22,000 miles on it all original, no modifications. It is an 1981 base model. Here is what it does. All through winter runs great. Summer hits with 95 degree heat and was running air conditioner and all of a sudden motor dies. Wait 15 minutes and cranks up and runs for about 10 minutes and happens again. does it again after started and then got home. Checked all Fluids and fine. What can I check or replace? Remember, just when it gets hot outside and dosnt happen in the winter.

 

it could just be a coincidence that this problem is summer heat related. but if so, it could be fuel related, like maybe vapor lock. don't know if that really happens to these or not, never experienced it. when it stops running check the carb to see if there's still fuel in it.

 

Fuel pump overheat, maybe? Ignitor overheat? Not much to go on until the prob can be isolated to electrical or fuel basis.

Not a common issue; I've run thru tons of 100+ days.

 

Perhaps the A/C idle compensator isn't holding the idle high enough.

 

^^ that would be my guess too, did you turn the A/C off the second time you cranked it?

 

Its not the air conditioner as the first time it did it I cut the airconditioner and after it cooled for 10 minutes it started and I drove it without airconditioner on and did it again. Appreciate you guys trying to help. I dont drive it to hard either (well sometimes I might ).

 

A fuel pressure gauge just before the carb will tell if it's vapor lock or not. Fuel issues tend to cause the engine to sputter out. Ignition issues usually act like one turned the key off.

 

If it is a vapor lock (it stutters like its out of gas) what is a good fix. Insulate the fuel line? If so, any tips? I take it if I had a fuel pressure gauge it would tell me I have lost pressure, correct? If so I would be on the road in hot weather stranded. But I would know.

 

vapor lock can be eliminated by adding a return line. if ur running stock carb, then it has a return. so I dont think vapor lock is the issue.

 

Back to square one then as I have a stock new Nikki. Does act like it is a gas issue. Any thing else I can check? Would bad ignitors act like that?

 

What would this have to do with the engine dieing and not restarting?

First thing you have to do is figure out the basics.

When it dies and will not restart you need to check to see if you have fuel going to the carburetor. Since you stated this is a 81 then the fuel pump should be on as soon as you turn the key on unless you have wired it differently. Keep a suitable container (coffee can or 1 gal fuel can) and some hose if you have to run it into the can and take the fuel hose off and turn the key on see if fuel is being delivered by the pump.


If that is good then check to see if you have spark the plugs. You would have to be losing spark to both the trailing and leading plugs in order for it to die.

Once you discover what you have lost (ignition or fuel) then you can start diagnosing from there.

 

Thanks. Basic info. I should have been smart enough to figure that. Thanks so much for your help.