Don:
I wrote a month or so ago about sooty plugs, the probable result of an overly rich running fuel/air mix. After running off and on all day on a recent trip from Elliott Bay, through the Ballard Locks and up to Lake Washington, the final 200 yard leg, after a brisk beat upwind, failed as the engine turned over but did not fire. I pulled up to the dock under jib power and looked into things the next day.
I suspected that the fuel pump had pooped out and investigated on the site the night before I returned to the boat. The majority of issues decribing my symptoms related to pin-hole, air ingesting fuel leaks, not fried pumps. When I pulled the cover off and tried another start, I had the same result as the night before. I ran the pump for a while before trying and it clicked away like normal. The next thing on the list was to check the plugs fearing that the hard cranking from the night before may have sucked some water into the chambers. The cylinders were thankfully dry. The plugs, however, were heavily fouled by dry, black soot like before. I cleaned them not expecting much. Upon re-trying the engine, it sprang to life and I was able to move the boat from its unofficial resting spot on a guest dock to it's proper slip. The fouling this time, created a debilitating and dangerous situation.
I am pretty certain that the fouling was caused by a very liberal main jet. I had noticed before that when trying to push to max RPMs while in gear, I was getting poor firing as though the choke was on. An excess of fuel could cause similar symptoms. I had already ordered an adjustable main jet from you that should arrive in the next day or two. I will replace the suspect part, replace the plugs, adjust it and the idle mix for max smooth-running leanness and see what difference it makes. I'll report back to see if we have a good fix and cleaner plugs.
Dave
I wrote a month or so ago about sooty plugs, the probable result of an overly rich running fuel/air mix. After running off and on all day on a recent trip from Elliott Bay, through the Ballard Locks and up to Lake Washington, the final 200 yard leg, after a brisk beat upwind, failed as the engine turned over but did not fire. I pulled up to the dock under jib power and looked into things the next day.
I suspected that the fuel pump had pooped out and investigated on the site the night before I returned to the boat. The majority of issues decribing my symptoms related to pin-hole, air ingesting fuel leaks, not fried pumps. When I pulled the cover off and tried another start, I had the same result as the night before. I ran the pump for a while before trying and it clicked away like normal. The next thing on the list was to check the plugs fearing that the hard cranking from the night before may have sucked some water into the chambers. The cylinders were thankfully dry. The plugs, however, were heavily fouled by dry, black soot like before. I cleaned them not expecting much. Upon re-trying the engine, it sprang to life and I was able to move the boat from its unofficial resting spot on a guest dock to it's proper slip. The fouling this time, created a debilitating and dangerous situation.
I am pretty certain that the fouling was caused by a very liberal main jet. I had noticed before that when trying to push to max RPMs while in gear, I was getting poor firing as though the choke was on. An excess of fuel could cause similar symptoms. I had already ordered an adjustable main jet from you that should arrive in the next day or two. I will replace the suspect part, replace the plugs, adjust it and the idle mix for max smooth-running leanness and see what difference it makes. I'll report back to see if we have a good fix and cleaner plugs.
Dave
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