Jet Slicker
New Member
Hey everyone! Really looking for some guidance with my 1998 Challenger 1800 with the twin 787’s. I am fairly well versed working on engines, but less knowledgeable on 2 strokes.
The boat has been sitting for 3 years and I purchased it. The starboard engine had oil in the cylinders (Presumed crank seals) so I got all the oil out, put a ¼ turn valve on, and got it running. I have about 30 minutes driving the boat and the port engine runs perfectly and I’m super happy with it. The starboard engine starts and idles fine, and has great throttle response. However, it would hardly go above 3500rpm in gear (Not rev limiter). Removed the intake screen and it ran better, but now it won’t go about 4000~4500rpm.. It runs great until it gets to that RPM and then it bogs. The more throttle I give, the worse it bogs. At WOT it will drop at least 300rpm and sounds the worst out of any throttle position. I pulled the plugs and they look a bit funky after just 20 minutes of run time. Neither of them smell like gas. The engine revs to 7k out of the water, but not in the water.
Things I’ve tried:
-Disassembled, cleaned, and reassembled both carbs. No notable problems and both pretty clean.
-Replaced line that goes from fuel pump to the crankcase (It didn’t seem cracked, but it was old
-Replaced fuel filters and oil filters for both engines
-Unplugged rectifier with no change
-Tried 2 sets of plugs
-When the engine is bogging, choke makes it worse
-Connections going to coil are tight and not corroded. Coil could be bad?
-Engine does not produce an abnormal amount of smoke, even when bogging.
I understand that I should probably do a compression test, but I won’t be able to grab my tester for another week almost. I’m not fully convinced the problem is bad compression, but who knows. The engine is original to the boat to my knowledge. Not super high hours, but the boat has been used. The port side engine was replaced 12 years ago.
Does anybody have any other leads? I was hoping to enjoy my week off without having to work on the boat all week but that’s not happening. I was hoping that somebody more knowledgeable and experience would have a lead. Any help is appreciated!
The boat has been sitting for 3 years and I purchased it. The starboard engine had oil in the cylinders (Presumed crank seals) so I got all the oil out, put a ¼ turn valve on, and got it running. I have about 30 minutes driving the boat and the port engine runs perfectly and I’m super happy with it. The starboard engine starts and idles fine, and has great throttle response. However, it would hardly go above 3500rpm in gear (Not rev limiter). Removed the intake screen and it ran better, but now it won’t go about 4000~4500rpm.. It runs great until it gets to that RPM and then it bogs. The more throttle I give, the worse it bogs. At WOT it will drop at least 300rpm and sounds the worst out of any throttle position. I pulled the plugs and they look a bit funky after just 20 minutes of run time. Neither of them smell like gas. The engine revs to 7k out of the water, but not in the water.
Things I’ve tried:
-Disassembled, cleaned, and reassembled both carbs. No notable problems and both pretty clean.
-Replaced line that goes from fuel pump to the crankcase (It didn’t seem cracked, but it was old
-Replaced fuel filters and oil filters for both engines
-Unplugged rectifier with no change
-Tried 2 sets of plugs
-When the engine is bogging, choke makes it worse
-Connections going to coil are tight and not corroded. Coil could be bad?
-Engine does not produce an abnormal amount of smoke, even when bogging.
I understand that I should probably do a compression test, but I won’t be able to grab my tester for another week almost. I’m not fully convinced the problem is bad compression, but who knows. The engine is original to the boat to my knowledge. Not super high hours, but the boat has been used. The port side engine was replaced 12 years ago.
Does anybody have any other leads? I was hoping to enjoy my week off without having to work on the boat all week but that’s not happening. I was hoping that somebody more knowledgeable and experience would have a lead. Any help is appreciated!
