Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Here’s a few modifications I’ve done with my FG-VT9.
I’ve put around 7 hours on my engine so far, and it only runs better and better.

I did have my ignitor go out, and am waiting for my new one to arrive soon.

Mods:

I removed the brass cam tappets, and noticed some light scuffing / friction marks on them. 

I polished the 4 tappets, and now they are extremely smooth and move without any friction.

I used a light polishing compound, and did a “valve seat job”  and now the valves seal even better.

I’ve been experimenting with various O rings, since I lost compression in one of my cylinders.  So far, the 1mm thickness 16mm Viton O rings (brown) have worked extremely well.  I also bought the green NBR type 1mm thickness x 16mm. 

When I had the pistons removed for installing the O-rings, I lightly wet-polished the piston skirts with 2000 grit sandpaper.

Before my ignitor or Hall sensor went out, I was getting the lowest, most solid idle I’ve ever gotten with my FG-VT9. 

Digital Tachometer reading was around 1220!   
It idled that low, and would idle so solidly without any stalling or stopping. Sucker would idle through a tank of fuel.  😁 Engine response and rev was perfect and very responsive.
Cylinder temperatures were extremely cool (110 degrees Farenheit) using a fan to keep the engine cool. 

I also made a set of stainless pushrod covers that look great.