I just recently repowered an old glasply with a 93 johnson 140. The motor runs great at speed and has good power. It's fairly low hours and still has good compression and all, but in the last couple weeks since I got it, it has started to misfire badly at idle, to the point where it basically won't run when it's warmed up.
When cold it will hold an idle alright, it won't stall out or anything, but it sneezes a bit. Once the motor warms up it starts sneezing badly at low throttle/idle and will stall repeatedly. I believe it's only the #4 cylinder (bottom port side) that is having problems as the other 3 plugs look identical, and very good (light brown) whereas the #4 plug is fouling, which seems odd to me as sneezing usually means that it's running too lean.
Basically I'm really confused about where to look. Here's what I've tried so far:
1. Replaced plugs and plug wires
2. Replaced port side recirc valves (the originals passed the "blow" test, but the one from cyl #4 was carboned up)
3. Sprayed carb cleaner through all orifices and jets
Here's the things I'm thinking it could be:
Starboard side recircs are plugged
Port side T shaped check valve is plugged
VRO pump is either leaking fuel into #4 or air (???)
Am I thinking along the right lines? Is there anything else it might be? Does this sound like as weird of a problem to anyone else? I can't understand how I'm fouling a plug and sneezing at the same time.
On a probably unrelated note the motor has this very strange wuffle sound when throttling back from high speed, the faster I pull the throttle back the more severe the noise. I'm guessing this is just air moving through the air silencer, but I'm paying attention to anything that sounds weird to me so I figured I'd mention it.
When cold it will hold an idle alright, it won't stall out or anything, but it sneezes a bit. Once the motor warms up it starts sneezing badly at low throttle/idle and will stall repeatedly. I believe it's only the #4 cylinder (bottom port side) that is having problems as the other 3 plugs look identical, and very good (light brown) whereas the #4 plug is fouling, which seems odd to me as sneezing usually means that it's running too lean.
Basically I'm really confused about where to look. Here's what I've tried so far:
1. Replaced plugs and plug wires
2. Replaced port side recirc valves (the originals passed the "blow" test, but the one from cyl #4 was carboned up)
3. Sprayed carb cleaner through all orifices and jets
Here's the things I'm thinking it could be:
Starboard side recircs are plugged
Port side T shaped check valve is plugged
VRO pump is either leaking fuel into #4 or air (???)
Am I thinking along the right lines? Is there anything else it might be? Does this sound like as weird of a problem to anyone else? I can't understand how I'm fouling a plug and sneezing at the same time.
On a probably unrelated note the motor has this very strange wuffle sound when throttling back from high speed, the faster I pull the throttle back the more severe the noise. I'm guessing this is just air moving through the air silencer, but I'm paying attention to anything that sounds weird to me so I figured I'd mention it.
