Mery Engine fuel system question

[Jasonb]

I've never used a jet on any of the propane fueled engines I have built, just an accurate flow control that will allow you to adjust down to a minimal amount of gas.

Also run the pressure a slow as possible, too high and it will just lift any valve or demand regulator.

Simple test to check if you have the right sort of air to gas mix is to place a candle by the exhaust as you turn the engine over by hand with the ignition off. You want a short blue flame as it exhausts, if you get a big orange one you have too much gas in the mix.

[Dave Otto]

Max uses a BBQ regulator that most likely only puts out about 3psi, and they are also adjustable which makes a difference in running.
As Jason has indicated there is only a needle valve which allows for very fine adjustment of fuel flow once the demand regulator opens.

Dave

[Alyn Foundry]

Don’t forget that you require a negative pressure differential for a demand style regulator. Placing jets of any size in the line will greatly reduce the performance.

Using a quality or fine adjustment regulator and preferably a closely fitted needle type valve is the best option.

   Graham.

[JBM3M]

I got a regulator that I can adjust down to as low as 1 lb, unknown accuracy, but it is minimal.  Still need to get it tried.  Trying to get ready for a snowbird trip down south for a few weeks and avoid some of the predicted cold weather.  Have not tried with demand valve as the pressure is too high and it opens the valve a bit. Yes I was trying to do it straight and all I got was a few pops early on.  Will try that candle thing, good idea.