40B engine improvements
Saturday, July 22, 2006
On Friday, July 21st Charley, Craig, and I worked in the 40B engine again. We swapped out the exhaust stacks for the downward direction which will eventually be needed. I had thought that might involve rusted bolts, but everything came apart easily.

We set the valve clearances, and went through the carb again. Since the engine did not run well the last time we ran it, we looked for what might be wrong. Craig suggested raising the gas tank higher above the carb so we mounted a new tank support.

Now the engine runs much better! It actually will come down to an idle and tick over, sort of.

We painted all of the engine gloss black. The carb will be painted later with a suitable color. The primer cup and the compression release were polished into the natural brass color and look very nice.

When tipped with the flywheel end of the engine downward, a considerable amount of oil leaks out the rear main “seal” which is only an oil slinger. This must be kept in mind during later storage because if parked facing uphill, it can lose a lot of oil. I plan to investigate any possible fixes for this, and eventually a shield can help keep the oil off the traction surface if the flywheel.

We discovered one rocker arm that had apparently been damaged and repaired in the past. It is not a good repair, but it works. However I will swap out that rocker arm for one off the display Model 40 engine.

— Dick Ray
3900

40B engine improvements