3.0l not accelerating/boggy

[hercules100]

Hello: This is my first post to site. I also have a SeaRay 1984 3.0 last week I was going across the lake 2500 rpm, trimed out and all of a sudden the engine just bogged down like it was out of gas, it idels ok, but know I have a "nocking sound" and I can feel it on the gunnels/floor. I idedled back to the dock and have been looking for problems everysince. I have changed the fuel filter, spark plugs, compression tested out at 140 psi even on all cylinders I also let the gauge set for 10 minutes on each hole, no bleeding back. oil is clean and full, checked timing, rotor cap and wires. I pulled the outdrive to check out the U-Joints and replaced the lower cable and water pump, they were ok, but replaced also the bellows, water pickup hose exhaust bellows, shift shaft bushings. seal kit etc. I'm scratching my head, but this is not helping.

 

[nola mike]

Hello: This is my first post to site. I also have a SeaRay 1984 3.0 last week I was going across the lake 2500 rpm, trimed out and all of a sudden the engine just bogged down like it was out of gas, it idels ok, but know I have a "nocking sound" and I can feel it on the gunnels/floor. I idedled back to the dock and have been looking for problems everysince. I have changed the fuel filter, spark plugs, compression tested out at 140 psi even on all cylinders I also let the gauge set for 10 minutes on each hole, no bleeding back. oil is clean and full, checked timing, rotor cap and wires. I pulled the outdrive to check out the U-Joints and replaced the lower cable and water pump, they were ok, but replaced also the bellows, water pickup hose exhaust bellows, shift shaft bushings. seal kit etc. I'm scratching my head, but this is not helping.

Did you try running with the outdrive off? A rod/bearing knock won't affect compression (and letting the gauge sit won't matter, they have a check valve in them).

 

[Scott06]

Would second running it w the OD off you can jam a hose in the water port on the bellhousing.

Also post a video to youtube etc and link it here. Hard to tell from the keyboard what the noise is.

 

[1979cvx20]

Hello: This is my first post to site. I also have a SeaRay 1984 3.0 last week I was going across the lake 2500 rpm, trimed out and all of a sudden the engine just bogged down like it was out of gas, it idels ok, but know I have a "nocking sound" and I can feel it on the gunnels/floor. I idedled back to the dock and have been looking for problems everysince. I have changed the fuel filter, spark plugs, compression tested out at 140 psi even on all cylinders I also let the gauge set for 10 minutes on each hole, no bleeding back. oil is clean and full, checked timing, rotor cap and wires. I pulled the outdrive to check out the U-Joints and replaced the lower cable and water pump, they were ok, but replaced also the bellows, water pickup hose exhaust bellows, shift shaft bushings. seal kit etc. I'm scratching my head, but this is not helping. So that way because

 

[1979cvx20]

The number one problem has always been water in the fuel after a boat has been sitting for a year or two. I know you say there's no water in the field but if you take the fuel line loose close to the carburetor and run 1/4 fuel into a glass jar and let it sit you will find your problem. I won't work on a boat if it doesn't have a water separator and I've been working on them for 45 years. My first question when somebody comes to me with a problem like this is show me where the water separator is. When it goes?? I say go get a water separator and install it and then you can bring the boat to me. Today's wonderful fuel attracts water like a sponge. The one I'm working on right now is one of my best friends boats. I bought him a what are separator in a carburetor and I told him to put the water separator on first. So of course she put the carburetor on First and try to drive it. When I got it the carburetor was full of water.
The number one problem has always been water in the fuel after a boat has been sitting for a year or two. I know you say there's no water in the field but if you take the fuel line loose close to the carburetor and run 1/4 fuel into a glass jar and let it sit you will find your problem. I won't work on a boat if it doesn't have a water separator and I've been working on them for 45 years. My first question when somebody comes to me with a problem like this is show me where the water separator is. When it goes?? I say go get a water separator and install it and then you can bring the boat to me. Today's wonderful fuel attracts water like a sponge. The one I'm working on right now is one of my best friends boats. I bought him a what are separator in a carburetor and I told him to put the water separator on first. So of course she put the carburetor on First and try to drive it. When I got it the carburetor was full of water.

 

[hercules100]

Thanks for getting back to me, now that you bring it up, I Had a similar problem years ago with my snowplow. I did replace the filter, and it looked clean, but I didn't check the gas in glass bottle after it had a chance to settle. The boat has not sat unused for more than a few days, as I go out at least twice a week weather permitting. But thinking back, I did let the tank get below a 1/4 tank on the gauge, may be some sediment in the bottom of the tank, the boat is a 1984. The spark plugs were a little darker color than normal, but I did idle in at 1000 rpm for at least 8 miles, if I got around 1500 rpm I noticed a (nock) it was a little high pitched for a rod, but I could definitely feel it on the bottom and gunnels of the boat, Oil pressure was steady at 55 psi and temp at 140. As soon as I get over this covid crap, I will get back to work on the boat, just don't have the drive to work on it. Can you please recommend a water separator and/or an additive to help clean out my tank, so many to choose from?? thanks Hercules

 

[hercules100]

Would second running it w the OD off you can jam a hose in the water port on the bellhousing.

Also post a video to youtube etc and link it here. Hard to tell from the keyboard what the noise is.

Thanks for getting back to me, good point about the check valve in Compression tester, I do have the drive off and the U-joints feel good but will check it out running as soon as I get rid of this covid crap, thanks again Hercules

 

[hercules100]

Hello again, I found the shifting problem, and all is well with that (intermediate shaft splines rounded off) The boat runs smoth and shifts great, however when it gets to 18 RPM it sounds like something is loose, I checked the starter, took the belt off, took the outdrive off but still have the noise. It sounds like a timing chain, but I think this boat has timing gears. Not sure if fuel pumps can make noise at the Arm/Cam point, but fuel presure is OK and the site window tube looks normal... Any Ideas!!!!

 

[hercules100]

Took off the fuel pump and found no problems, spring is place and in good shape, getting ready to take off the valve cover and check that area out, but it just doesn't sound like valve noise..

 

[Scott06]

Took off the fuel pump and found no problems, spring is place and in good shape, getting ready to take off the valve cover and check that area out, but it just doesn't sound like valve noise..

You are correct it has timing gears. You can rotate crank back and forth and see if there is excessive backlash before cam start moving.

Also you may want to make sure the balancer is tight and not making a noise.

 

[hercules100]

Took off valve cover and found no problems, put new coil, wires, NGK plugs, cap and rotor, took the boat out for another test, at idle it sounds normal, at 1500 rpm; slight nock, at 2000 rpm the knock is very noticeable. Looks like a winter project!! Now I have to find a cherry picker with enough lift to clear the gunnels, looks like I need around 90 inches, may have to remove tires from trailer, should be fun. I am in hopes the problem is with the flywheel or motor coupling, but my luck doesn't run that way... at least I got a 10# Mackinaw Laker while running on my trolling motor, tonights dinner.

 

[Scott06]

Took off valve cover and found no problems, put new coil, wires, NGK plugs, cap and rotor, took the boat out for another test, at idle it sounds normal, at 1500 rpm; slight nock, at 2000 rpm the knock is very noticeable. Looks like a winter project!! Now I have to find a cherry picker with enough lift to clear the gunnels, looks like I need around 90 inches, may have to remove tires from trailer, should be fun. I am in hopes the problem is with the flywheel or motor coupling, but my luck doesn't run that way... at least I got a 10# Mackinaw Laker while running on my trolling motor, tonights dinner.

Some tool rental places have them in a tow behind size. If you have a beam in your shop you can use a a chain fall. A often overlooked way is a wrecker with a boom, basically the cost of a tow