I am looking for suggestions on what to look for please. I've only had this new to me boat out 3 times since July.
1st trip: No issues, ran great
2nd trip: No issues, ran great
3rd trip: Right off the trailer engine would fire then pop and die over and over again. No throttle response whatsoever. I ran off the trolling motor for a bit until the sun came up and didn't do anything other than poke around at stuff on the engine. Fired up and ran for the next few hours. Starting, stopping, high rpm, low range etc. etc. I burnt probably 4 gallons running all over the lake. Then it started cutting out and bogging down under load. I changed the spark plugs with no change.
Got it home and decided to start taking a look. (I'm new to OB's, but somewhat mechanically inclined) Wiring was done very poorly with bad connections and too many splices, even a wire nut! for my comfort level. Two different styles of coil w/ one being much older, very old fuel lines/hoses. I decided to give it my best and throw some preventive maint at it since components like the power pack and coils had exposed wires and things. Don't knock me for replacing parts.. was going for the benefits down the road of having new components installed.
Here is what I have done:
-Rebuilt Carb, No residue or buildup present, yes I pulled the high speed jet and cleaned it w/ carb cleaning wires. Soaked for a few hours in chem dip and washed off with water and blown out through the passages. The mixture screw was not 1-1/4 turns out. I lost count, but it was in the neighborhood of 5 turns. I did not remove the lead plugs, possibly my issue now.. please keep reading.
-New Coils
-New Powerpack
-New fuel pump/gasket
-Adjusted throttle linkage per the manual (it previously was not opening the butterfly fully)
-New fuel line and oil return/telltale line
-Wiring issues resolved and poor connections corrected
-New primer bulb/hose
-Gas tanks drained and filled w/ fresh mix
After all the work, I cranked the engine on muffs in the driveway. No go. Choke in, choke out, no difference. It's an electric start converted to manual choke.
-Compression on both cylinders was 110. Read 120 when I brought it home, not sure why the different reading.
-New Champion plugs gapped @ .40
-Spark test showed a thin ~1/64"-1/32" blue/white spark reaching 7/16 on a gap tool. (It was in the sun and I was shading it with my hand) It's hard to tell how thick the spark was since it isn't a straight line, but I was expecting a fat 1/8" lightning bolt based off some of the responses I've read. Is this concerning?
- Fuel bulb got rock hard.
Still not even a hint of pop bang happening. I set my idle mixture screw at 1-1/4 as the air box sticker tells me to so I started turning that screw further out as I remembered when I took the carb apart it was no where near 1-1/4. Got to about 3-1/2 turns and it started popping then dying. Finally settled at 5-1/2 turns out and it stayed running. 5-1/4 turns out and the idle sped up a tad. Now it starts runs and responds to the throttle (still on muffs). Let it run for a few minutes with good telltale water and the idle was hanging right around 900 rpm. All of a sudden it drops 200 rpm then comes back up. Then drops again a few hundred. Basically running like crap. Turned it off and put it away for the night.
Other than rebuilding the carb again, which I just did is there anything else that could cause my issue? Is the spark as I described acceptable?
1st trip: No issues, ran great
2nd trip: No issues, ran great
3rd trip: Right off the trailer engine would fire then pop and die over and over again. No throttle response whatsoever. I ran off the trolling motor for a bit until the sun came up and didn't do anything other than poke around at stuff on the engine. Fired up and ran for the next few hours. Starting, stopping, high rpm, low range etc. etc. I burnt probably 4 gallons running all over the lake. Then it started cutting out and bogging down under load. I changed the spark plugs with no change.
Got it home and decided to start taking a look. (I'm new to OB's, but somewhat mechanically inclined) Wiring was done very poorly with bad connections and too many splices, even a wire nut! for my comfort level. Two different styles of coil w/ one being much older, very old fuel lines/hoses. I decided to give it my best and throw some preventive maint at it since components like the power pack and coils had exposed wires and things. Don't knock me for replacing parts.. was going for the benefits down the road of having new components installed.
Here is what I have done:
-Rebuilt Carb, No residue or buildup present, yes I pulled the high speed jet and cleaned it w/ carb cleaning wires. Soaked for a few hours in chem dip and washed off with water and blown out through the passages. The mixture screw was not 1-1/4 turns out. I lost count, but it was in the neighborhood of 5 turns. I did not remove the lead plugs, possibly my issue now.. please keep reading.
-New Coils
-New Powerpack
-New fuel pump/gasket
-Adjusted throttle linkage per the manual (it previously was not opening the butterfly fully)
-New fuel line and oil return/telltale line
-Wiring issues resolved and poor connections corrected
-New primer bulb/hose
-Gas tanks drained and filled w/ fresh mix
After all the work, I cranked the engine on muffs in the driveway. No go. Choke in, choke out, no difference. It's an electric start converted to manual choke.
-Compression on both cylinders was 110. Read 120 when I brought it home, not sure why the different reading.
-New Champion plugs gapped @ .40
-Spark test showed a thin ~1/64"-1/32" blue/white spark reaching 7/16 on a gap tool. (It was in the sun and I was shading it with my hand) It's hard to tell how thick the spark was since it isn't a straight line, but I was expecting a fat 1/8" lightning bolt based off some of the responses I've read. Is this concerning?
- Fuel bulb got rock hard.
Still not even a hint of pop bang happening. I set my idle mixture screw at 1-1/4 as the air box sticker tells me to so I started turning that screw further out as I remembered when I took the carb apart it was no where near 1-1/4. Got to about 3-1/2 turns and it started popping then dying. Finally settled at 5-1/2 turns out and it stayed running. 5-1/4 turns out and the idle sped up a tad. Now it starts runs and responds to the throttle (still on muffs). Let it run for a few minutes with good telltale water and the idle was hanging right around 900 rpm. All of a sudden it drops 200 rpm then comes back up. Then drops again a few hundred. Basically running like crap. Turned it off and put it away for the night.
Other than rebuilding the carb again, which I just did is there anything else that could cause my issue? Is the spark as I described acceptable?