Today I made progress ! 🙂
Started going through all the issues I picked up last week, and things to check on. So yes;
- Fixed the butterfly valve in the carburetor. It’s now fully open with full throttle setting.
- Rechecked the tapped clearance on all valve’s. Made a few little adjustments, nothing mayor, but has to be right !!
- Checked the ignition time for both magneto’s. Yes both are 30 deg before TDC (top dead centre).
- Checked the valve timing. All looking good with valve time overlapping; exhaust closing and mixture opening at TDC.
- Drained the 91 octane petrol from the fuel tank, and filled it up again but this time with 95 octane petrol.
Because the carburetor butterfly valve is now a bit more open, starting the engine took a little getting used to. Needed 3 starts, but yes runs beautiful again. Pretty sure that after warming up the engine, it runs a bit better/faster now. The tacho needle is now on the 1900 and starting to touch the 2000 mark.
Some improvement, FINALLY !!!!!
At the moment I am running the engine without a exhaust. I am thinking that instead of putting the ring exhaust back, that I should try to make short stubs for all 5 cylinders. This will completely isolate the 5 exhausts. Read this post for the explanation.
The image here from the book, “Ghosts, the great war“, shows you what it will look like ! 🙂
Maybe a bit hard to see… The top cylinder and the next one to the right have two stubs sticking out to the right. The cylinder to the left of the top one has an exhaust stub sticking out to the left. I can’t see the bottom two stubs but they must just point down… And one of the down going stubs will be used to create carb heat, which will stop the carburetor from freezing up.
Measured the nuts that clamp the exhaust stubs onto the cylinder. I need to source or make 1 3/4″ nuts with 16 threads per inch. If I can do that, I will organise the exhaust stubs !