quickRick

my 1970- 3020 gas, when running at high rpm under load, after about 45-60 min, will sputter and quit. cannot restart it, have to leave it sit about 2 hours before it will start and then the cycle repeats itself. I replaced the fuel filter thinking that was the problem "not" antifreeze level is correct and raditor side screens are clean. The raditor cap dosn't seam to get real tight and will turn past the tight spot and go loose. Im not sure what to do I don't think that the cap could be sine it's been that way long before this problem has started.

tractor beam

Welcome to the forum Rick! Most likely fuel related........Check to be sure your fuel cap is venting properly, nothing in the fuel tank as in dirt. After that, if it doesn't cure it, I'm guessing the carb.

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jd3520turbo

Sounds to me if it is not a gas venting issue, then I would look at the coil. When a coil starts to go bad, they loose their zip when they get hot. Then, when they cool off, they begin working again. I would swap out the coil and see if that doesn't help your issue.

Good Luck.