Hard starting hot

[JimmyC]

My Pinz takes a lot longer to start when it is hot. It starts instantly when engine cold regardless of air temp. Takes a bit of cranking when hot. Ideas?

[pinzinator]

Heat may be affecting the coil.

[JimmyC]

Did not think of that.

[David Dunn]

Check your charging voltage. If something's wrong with the voltage regulator or the alternatorr and gives out over 30 volts that will overheat your coil

[whitesik]

What is the interval between starts? Long enough for the fuel to evaporate in the bowl in hot weather? Are you using the "choke" in hot weather; full? half? There are many variables.

[JimmyC]

If I leave it off just a minute or two it is fine. If I leave it off an hour it is fine. In between it is likely to be balky.

[eric1355]

Hello
valve clearances too low?
Eric

[rmel]

JimmyC... What you are describing may be heat soak into the intake manifold.
I have experienced this first hand on my Carb'd 712. It is more prevalent if the
intake manifolds are not insulated.

Styer-Puch had a hot climate version of the Pinz and one thing that was done was
to insulate the intake to prevent heat soak. I believe mid to late 73' all versions
incorporated insulated intake manifolds "pants".

What happens is....while running, air flow keeps the pants from getting too hot.
But when you turn the engine off, heat rises from the cylinders/heads and can get
the pants to a high enough temperature that when attempting to start, the higher
volatiles boil off immediately inside the manifolds resulting in difficult to combust mix.
That condition takes in the ballpark of 10 to 15 minuets happen and about 40 minutes
to correct (will vary depending upon altitude, ambient temp, and if your running
Summer or Winter blend).

This happened to me a couple of times; conditions were, elevation, hot day, cranking
away on a grade, stopped for 15 minuets then won't start. On the trail all I had to do
was take the dog house cover off to vent heat out -- after 15-20 minutes started like
there was never anything wrong! My pants were not insulated, now they are. If yours
aren't I'd recommend you get the insulation kit from SAV.

[ChickenPinz]

I believe this is one reason the carb-to-intake gasket is so thick -- thermal insulation.
https://swissarmyvehicles.com/pinzgauer ... carburetor

[rmel]

Yes, that is correct!

[JimmyC]

So my intake manifolds are insulated. I suspect it is carbs, mostly because my ignition is solid and my carbs are decrepit (but rebuilt). It will start when hot but just takes a lot of cranking. I sometimes wonder if I am boiling the fuel in the bowls. I don’tthink it is the coil because once it starts one it starts easily again.