Thread: Sooty Plugs
View Single Post
  #17   IP: 76.173.181.116
Old 08-14-2019, 07:58 PM
SubtoSail SubtoSail is offline
Senior Member
 
Join Date: Feb 2018
Location: Oahu
Posts: 23
Thanks: 2
Thanked 9 Times in 7 Posts
Jerry, thanks for the kind words. I definitely appreciate your thoughts and time, always nice to have someone to talk story with. It is reassuring to have a second opinion that overall, the engine seems to be in good shape and is not past her prime.

I feel a little silly regarding the throttle stop. Somehow I have either never noticed it, or never thought that it would be something useful to have and have never looked for it. Up until yesterday, my idling was with the throttle plate completely closed, confirmed by the control linkage on the carb. From there, I would adjust the mixture screw on the rear of the carb to get as good of a sound as I could. Based on Jerry's ears, that was probably down around 600 RPM or lower. We used the throttle stop to set the idle RPM, which clearly makes sense. By idle, I mean the spot where the throttle cable can no longer move. I think in an ideal world the engine would idle smoothly at an RPM above self sustaining with the throttle plate completely closed (no need for a throttle stop screw), but that just might not be a reality. Any thoughts or experience on setting the idle RPM with the screw on the throttle linkage?

Plugs are RJ-12C. The spares I have are a different brand, based on which ones are on the island when I buy them, but the current ones installed are RJ-12C.

The alternator belt is loose, so I will definitely tighten that up. I can check the voltage at the coil, if required.

The exhaust leak is between the manifold and the flange on the hot exhaust pipe. The leak is new and high on the fix list, only developed since removing the hot pipe in search of a blockage. I suspect I didn't scrape the old gasket completely off, and the new gasket isn't able to make a good seal.

Neil, I do have the test port in the exhaust flange, but I have not tested the back pressure. I have taken the sections apart to visually look for a blockage and found none. The water coming out of the transom batches normally, and when revving the engine it shoots rather surprisingly. The float though...

My memory of the carb assembly procedure is to screw in the float seat, drop in the needle, and put the float on. Then verify that the float is resting parallel when held upside down. My float seat is screwed all the way in. I have always screwed it completely in, checked the float, and decided it looked parallel. When I take the carb apart I'll take a picture of this step. Does the float seat normally go all the way in, or does it usually get backed out some to make the float parallel?

As for floats leaking, do you mean them filling with gas and no longer floating, or the float valve not seating? Either way, it requires a carb disassembly.

The plugs are sooty, which indicates a rich mixture. But we didn't see any other indications of a rich mixture, such as wetness on the plugs, blue exhaust smoke, or gas sheen around the exhaust port.

Thanks for all the helpful advice,
Joe
Reply With Quote