OK, so here's the background. I bought this boat a month ago or so, and have been working on it ever since, and quite frankly it is really starting to irk me. It's a '78 Bayliner 21' Skagitt Sunbridge with a Volvo/GM 5.7 260hp with a 280 single prop outdrive.
I have been battling some issues...to say the least! When I first got it it wouldn't turn over, put a good starter on it and it turned over but wouldn't start. I tried rebuilding the carb, but the carb body was junk (corrosion pitted the gasket surfaces) so I bought a rebuilt Quadrajet carb from what I thought was a good rebuild company....not so sure now. I put the carb on and it would idle, but was surging so I replaced the mechanical fuel pump with a new one (Volvo OEM).
It ran better, but was running WAY lean, so I pulled the carb, reset the float level and checked the metering rods and jets.....The original carb had 69 jets and 35 metering rods on the primary and the "new" rebuilt had 70 jets w/53 metering rods (of which 1 was bent...ugggg). Cannot imagine the 53 metering rods are right for this application knowing what the old carb was set as so I swapped the 35 metering rods into the new carb and also swapped the secondary metering rods since they to looked way lean.
After the changes it was running way better, got on step good, cruised about 3500rpm at 28MPH, but still couldn't reach WOT above 4000rpm.
By this time I had replaced the following: fuel pump, all fuel lines, fuel/water seperator (actually twice), coil, cap/rotor/wires/plugs, rebuilt distributor and new points/condenser.
At this point I am frustrated and confused....I am "carburetor retarded" and really hate working on them but I am shure it is what the problem is, but don't know where to go from here.
Here is what it is doing now....starts easy, idles great, pull out of the harbor and give it throttle and it bogs hard at 2000rpm, feather the throttle and and I can get it up un step and cruise at 3500rpm.....when cruising if I touch the throttle, up or down, it stumbles..........HELP
I know there is a lot of Q-jet posts on here, and I have read several, but like I said I am "carburetor retarded" so I need someone who can help put it in simple terms for me. BTW, timing is correct at 8 deg BTDC per spec.......
I have been battling some issues...to say the least! When I first got it it wouldn't turn over, put a good starter on it and it turned over but wouldn't start. I tried rebuilding the carb, but the carb body was junk (corrosion pitted the gasket surfaces) so I bought a rebuilt Quadrajet carb from what I thought was a good rebuild company....not so sure now. I put the carb on and it would idle, but was surging so I replaced the mechanical fuel pump with a new one (Volvo OEM).
It ran better, but was running WAY lean, so I pulled the carb, reset the float level and checked the metering rods and jets.....The original carb had 69 jets and 35 metering rods on the primary and the "new" rebuilt had 70 jets w/53 metering rods (of which 1 was bent...ugggg). Cannot imagine the 53 metering rods are right for this application knowing what the old carb was set as so I swapped the 35 metering rods into the new carb and also swapped the secondary metering rods since they to looked way lean.
After the changes it was running way better, got on step good, cruised about 3500rpm at 28MPH, but still couldn't reach WOT above 4000rpm.
By this time I had replaced the following: fuel pump, all fuel lines, fuel/water seperator (actually twice), coil, cap/rotor/wires/plugs, rebuilt distributor and new points/condenser.
At this point I am frustrated and confused....I am "carburetor retarded" and really hate working on them but I am shure it is what the problem is, but don't know where to go from here.
Here is what it is doing now....starts easy, idles great, pull out of the harbor and give it throttle and it bogs hard at 2000rpm, feather the throttle and and I can get it up un step and cruise at 3500rpm.....when cruising if I touch the throttle, up or down, it stumbles..........HELP
I know there is a lot of Q-jet posts on here, and I have read several, but like I said I am "carburetor retarded" so I need someone who can help put it in simple terms for me. BTW, timing is correct at 8 deg BTDC per spec.......