Build Review --RETROL HM-01 7cc Model Hit and Miss 4-stroke Horizontal Internal Combustion Engine

Greetings everyone, and thanks for all the comments. To address a few popular comments.....This model was built per the manufacturers instructions. The oil holes in the bearing caps are shown to be positioned on top, although being on the bottom makes sense too. But remember, an access hole can also act as a drain. As for the constant spark, the cam behind the timing gear drives a block that breaks a set of points and opens the ignition circuit. I'm guessing that eliminates the possibility of the electrical continuity you would need to produce a spark.

Saturday night I got my Labrador Retriever by my side and a new Joe Pie video to watch. Life is great.

Joe, I own and display hit n miss engines at shows and and participate in farm shows for school kids . A hit n miss engine speed is controlled by a governor which holds the exhaust valve open during the Miss cycle. The engine can’t build compression therefore coasts until the engine slows enough for the governor to release the latch on the exhaust valve letting the engine build compression and then fire. They were used because they were very economical but had the disadvantage of not having a constant speed. They were used for running pumps , crème separators or anything that did not need a constant speed . During the same time period they also made throttle governed engines that were used to run machinery that needed a constant speed . Hope this helps and glad to see the model build 😊 !

These are great kits to spend time with the grandkids as thay learn the past ,,, YOU GOT to run it that's the best part of the build as it opens smalleyes makes small ear to ears smiles and laughter!,,, even for old bag of bones like us 😂😂😂😂😂😂

Good to see you again Sir.

Another way to think on the holes in the bearings. If they are pointed down, the groove will fill with oil and act as a reservoir. Up, a bubble can form in the hole of the bearing and the oil just fills the groove. If that latter happens the bearing could run dry. Great video! CMW

We are all kids at heart

The small notch in the pulley on the side of the flywheel is for a rope with a knot to be used for wrapping around the pulley to start the engine. Our lawn mower when I was growing up had a Briggs & Stratton engine which had a similar arrangement for starting it. This was before the days of recoil-starting attachments. The taper of that notch will indicate the running direction of the engine. The knot is placed in the notch and the rope is wound around the pulley such that as the rope is pulled, the crankshaft is turned and when the rope is pulled off of the pulley, it will just slide out of the notch.

I wanted to hear it run

Thanks Joe, I'd love to see this little hit and miss engine running!

Great to see you posting again. I believe that PM Research and Stuart both offer machined versions of some (not all I think) of their engines for those who don't have machine tools - just another option. That is one good looking model though - fit and finish looks pretty good (mostly).

I agree, it's a beautiful kit. thank you for sharing.🙂🙂

Just a heads up, this engine was designed by David Kerzel, who has offered free plans for it for 20 years or so. I built one from scratch a few years back and it was a fun project! Its a shame they used his design and didn’t even give him any credit.

Nice model.Thank you,Joe.

I enjoyed watching you assemble this little engine. Thanks for sharing your experience with what looks like an awesome kit.

That is so cool, thanks Joe!

great kit

Thanks again

Very cool model Joe 👍👍 Thanks for sharing...

Top job again