g741.org

I haven't driven my own M42 much at all, perhaps a 150 miles or so, and won't be able to handle the pedals for several more weeks as I re-habilitate my knee replacement. But while it starts just fine when cold (after all, it has the 100 amp/24 vold OEM system), a hot restart can take some cranking. I know holding the gas pedal down can't "air out the cylinders" of dripped gas from the carb, so I am wondering if turning the heat riser off may help, if some of the hot restart crankiness may be vapor lock too. My truck does have the fuel pump heat shield, and not only the original fuel pump but also a switched electrical fuel pump. Since I live in Upstate SC, I don't imagine I really need carb heat for smooth drivability, and to avoid traffic stalls, I keep the idle knob pulled out, keeping the idle revs up a bit. I am pretty sure right now the riser is on "heat", but my truck sits a hundred miles away for now in my son's work garage. The operator's manual says not to use the choke on a hot restart.

Maybe I just need more miles and driving experience to see what my own truck wants to make for quicker hot restarts. And here is my M 42's powerplant.
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If you can close the heat riser I would do so, or just a little will work.
But most of the time there froze and won't move.

99% sure your problem is a dripping carb(flooding) and needs a rebuild,
Or very least the float level checked.

Vapor lock condition wouldn't start until after it cools down, no matter
How much you crank it.
Tom

OK, thanks, I will check into the carb. I was pretty good with making tuning adjustments to race Holley's, SU's, and Strombergs, so hopefully won't be impossible for me to figure this one out.

Mine has always cranked a bit longer on a hot restart. I don't use the choke and my heat riser is frozen in place. I think it's a familiarity thing-once I got used to it and put some miles on it, it starts a bit faster to me.
Gary

I cut my heat riser butterfly out when I had the manifolds apart om my truck

and it seems to start very good now that it turns over fast and has excellent spark

It's been years since I don't have a carb in my M37. (20 now that I think of it) but I remember that when the engine was hot, I just have to kick the throttle twice before starting and then it cranked half turn and it was purring like a flathead kitten.

Man I feel old now. This post made me think of it and realize that 1997 was the year I've started the diesel conversion on my M37. It seems it was yesterday when I posted in the old Big E forum. I remember having to scan paper pictures to share them in the forum. (no digital camera at that time)
I Don't have much time to post these days so I'm not so active here as I was then, though I read from time to time. The M virus is hard to beat.

Good to see that new blood is pumping in the forum.

Juan, good to hear from you again.

As to heat risers, I read this article years ago, and thought it worth bringing up again here: http://www.dodgepilothouseclub.org/know ... bunked.pdf