Gas Giant
Petty Officer 1st Class
- Joined
- Aug 8, 2010
- Messages
- 239
I'm not sure if I should put this here or in an engine topic....I apologize if I got it wrong.
The boat is a 1988 Cobia 17 foot center console, with a 1988-ish Force 50 motor. The engine starts and runs wonderfully - I just bump the key and it fires. It also has great compression (135 on each cylinder) and is running on both cylinders. The disadvantage to this engine is that there is no power tilt setup, meaning that to adjust the tilt I have to move a metal rod to one of about 5 different settings. (with the engine off of course, because one has to be standing behind it to do this)
So, I took it for a test drive in the river on Thursday. The boat didn't behave as well as I hoped - it wouldn't plane out, and engine didn't want to rev to WOT. I base this purely on sound, as I don't have a tach yet since 20-pole tachs aren't that easy to find or that cheap. The engine ran smooth as silk, but it just wasn't making maximum power (almost sounded like half-throttle, but who knows for sure) and it was pushing the bow up but not planing out. The boat was also moving along pretty darn slow, but making a huge wake.
We went to an island in the river where I tried adjusting the trim somewhat. On the way out, it was set at the furthest hole from the boat. I adjusted it to one of the middle holes, but it made no difference in how the boat performed. When we finally got back to the boat ramp, I had nearly burned almost all of my 6 gallons of gas, despite the island and boat ramp actually being within sight of each other (albeit they are still pretty far apart)
I think I may have a combination of problems. The first thing I'd like to point out is that I believe my anti-cavitation plate is down too low on this engine - its around 1.5-2" below the lowest point on the transom. See if you can tell what I mean in this pic:
Does that look too low? I couldn't get a clear picture of what the symptoms of having the engine mounted too low are from doing various searches, so I am not sure if this is a problem or not. However, if it is, I am going to have to get a jack plate, as I can't go up any more mounting holes on the engine.
I have no idea what the angle of the prop is - could this also be a culprit?
As far as weight distribution, I was in the center of the boat (around 225 lbs), the battery, engine and gas tank were near the back of the boat, and my friend (probably 235-240) was sitting on the seat near the bow of the boat. I may be able to relocate the battery if I do some wiring, but there really isn't any other place to put the gas tank.
I also checked the WOT setting of the carburetor, and with the control lever at wide open, the carb butterfly is horizontal, so that is set up correctly.
Anyway, any ideas are greatly appreciated, as I feel that I am getting really close to having a working boat for the first time in my life! :grin:
The boat is a 1988 Cobia 17 foot center console, with a 1988-ish Force 50 motor. The engine starts and runs wonderfully - I just bump the key and it fires. It also has great compression (135 on each cylinder) and is running on both cylinders. The disadvantage to this engine is that there is no power tilt setup, meaning that to adjust the tilt I have to move a metal rod to one of about 5 different settings. (with the engine off of course, because one has to be standing behind it to do this)
So, I took it for a test drive in the river on Thursday. The boat didn't behave as well as I hoped - it wouldn't plane out, and engine didn't want to rev to WOT. I base this purely on sound, as I don't have a tach yet since 20-pole tachs aren't that easy to find or that cheap. The engine ran smooth as silk, but it just wasn't making maximum power (almost sounded like half-throttle, but who knows for sure) and it was pushing the bow up but not planing out. The boat was also moving along pretty darn slow, but making a huge wake.
We went to an island in the river where I tried adjusting the trim somewhat. On the way out, it was set at the furthest hole from the boat. I adjusted it to one of the middle holes, but it made no difference in how the boat performed. When we finally got back to the boat ramp, I had nearly burned almost all of my 6 gallons of gas, despite the island and boat ramp actually being within sight of each other (albeit they are still pretty far apart)
I think I may have a combination of problems. The first thing I'd like to point out is that I believe my anti-cavitation plate is down too low on this engine - its around 1.5-2" below the lowest point on the transom. See if you can tell what I mean in this pic:
Does that look too low? I couldn't get a clear picture of what the symptoms of having the engine mounted too low are from doing various searches, so I am not sure if this is a problem or not. However, if it is, I am going to have to get a jack plate, as I can't go up any more mounting holes on the engine.
I have no idea what the angle of the prop is - could this also be a culprit?
As far as weight distribution, I was in the center of the boat (around 225 lbs), the battery, engine and gas tank were near the back of the boat, and my friend (probably 235-240) was sitting on the seat near the bow of the boat. I may be able to relocate the battery if I do some wiring, but there really isn't any other place to put the gas tank.
I also checked the WOT setting of the carburetor, and with the control lever at wide open, the carb butterfly is horizontal, so that is set up correctly.
Anyway, any ideas are greatly appreciated, as I feel that I am getting really close to having a working boat for the first time in my life! :grin:
