06z400rider
Cadet
- Joined
- Feb 17, 2012
- Messages
- 13
Hi guys, newbie here. I recently bought a boat with a 1959 Evinrude 18 hp Fastwin on it. It was only firing on one cylinder at the time and the previous owner had just spent $350 on repairs. They had installed new points, condensers, coils, and possibly a carb kit, from what I'm seeing. Still not firing on bottom hole. Here's a list of things I've done: One coil was slightly loose and had moved enough to graze the flywheel magnet. I clearanced and tightened it down; points were gapped at .025-.026. Regapped to .020. Checked compression and got 90-95 psi on both holes. Of course I've been through several sets of plugs in a couple hours run time and playing with it. Currently running J4C or J6C. Also tried
J8C. Figured out spark plug wire was being piched between a bracket and timing advance mechanism and keeping me from opening throttle completely. Moved it. I then went to clean spark plug threads to ensure that plugs were able to ground properly to head and fire consistently when I noticed the bottom hole is stripped. I pulled the head and cleaned it, the cylinder and top of pistons and relubed. Helicoiled threads and punched well with spreader to ensure they dont move in or out. Now firing on both holes and runs MUCH better. Here's the tricky part. Took it out and tried it expecting great things and it is better but still doesn't go over 10 MPH on a 15' jon boat. Timing light shows fire on both cylinders and plugs look the same for both now, so I know I fixed the dead miss. But I noticed the carb is flooding and pouring gas out when trimmed up. Also uses WAAAAAY too much fuel due to the waste. Once I got this second hole firing, I noticed the pressure fed gas tank has excessive pressure on it and figured it's pushing too much fuel to the carb. Confirmed it by bleeding some pressure off tank while coming in yesterday, and the thing jumped up on top of the water and ran 25 MPH or so for about a mile to the ramp. I must have too much crankcase pressure, or is there some way the crankcase regulates it with a positive crankcase pressure valve or something? Should the tank vent at a certain pressure? I don't think piston rings are bad, and I pulled carb today. Needle and seat look fine, as well as float. All looks new. I also pulled reed valves and cleaned them. Also checked the rubber check valve assembly and cleaned. I did notice there is another reed valve looking piece on the left side- one small brass strip that appears to vent crankcase pressure back toward the intake manifold??? It had red paint chip under it, holding it open and I removed, cleaned, and reinstalled it. Any ideas what that piece is or what it does? And could it cause it, or am I missing something? I know for a fact that I have too much pressure on the tank and relieving it stops the flooding and sends me flying down the river. Would back pressure on the exhaust system cause crankcase pressure? Someone who knows will find this simple, but I'm a compressor mechanic, not an outboard guy. Thanks for the help! Sorry so long!
J8C. Figured out spark plug wire was being piched between a bracket and timing advance mechanism and keeping me from opening throttle completely. Moved it. I then went to clean spark plug threads to ensure that plugs were able to ground properly to head and fire consistently when I noticed the bottom hole is stripped. I pulled the head and cleaned it, the cylinder and top of pistons and relubed. Helicoiled threads and punched well with spreader to ensure they dont move in or out. Now firing on both holes and runs MUCH better. Here's the tricky part. Took it out and tried it expecting great things and it is better but still doesn't go over 10 MPH on a 15' jon boat. Timing light shows fire on both cylinders and plugs look the same for both now, so I know I fixed the dead miss. But I noticed the carb is flooding and pouring gas out when trimmed up. Also uses WAAAAAY too much fuel due to the waste. Once I got this second hole firing, I noticed the pressure fed gas tank has excessive pressure on it and figured it's pushing too much fuel to the carb. Confirmed it by bleeding some pressure off tank while coming in yesterday, and the thing jumped up on top of the water and ran 25 MPH or so for about a mile to the ramp. I must have too much crankcase pressure, or is there some way the crankcase regulates it with a positive crankcase pressure valve or something? Should the tank vent at a certain pressure? I don't think piston rings are bad, and I pulled carb today. Needle and seat look fine, as well as float. All looks new. I also pulled reed valves and cleaned them. Also checked the rubber check valve assembly and cleaned. I did notice there is another reed valve looking piece on the left side- one small brass strip that appears to vent crankcase pressure back toward the intake manifold??? It had red paint chip under it, holding it open and I removed, cleaned, and reinstalled it. Any ideas what that piece is or what it does? And could it cause it, or am I missing something? I know for a fact that I have too much pressure on the tank and relieving it stops the flooding and sends me flying down the river. Would back pressure on the exhaust system cause crankcase pressure? Someone who knows will find this simple, but I'm a compressor mechanic, not an outboard guy. Thanks for the help! Sorry so long!
