Mercruiser Inboard/Outboard 3.0L Alpha One

[miguelmaul]

I have a Mercruiser Inboard/Outboard 3.0L Alpha One attached to a 2004 Bayliner 175. It has been running poor ever since I pulled it out for the summer and had it summerized. I just had my mechanic clean my carburetor, change my spark plugs and inspect my fuel delivery system. But now it has poor speed/acceleration it idles ok a bit ruff at the beginning and then once I get it going I put my throttle all the way forward and it only does about 10 mph or less. Any help would be great thanks.

[oldjeep]

Sounds like the choke might be sticking. Are you getting any noticable smoke when you run it on the muffs?

Also could be that the mechanic put the plug wires back on wrong.

[miguelmaul]

Well I don't see no smoke and my mechanic did not put the wires backwards because it starts up the problem Im having now is it not going more that 10 mph.

[oldjeep]

Well I don't see no smoke and my mechanic did not put the wires backwards because it starts up the problem Im having now is it not going more that 10 mph.

The engine will start and idle (poorly) with the plug wires in the wrong location

Easy enough to check

[miguelmaul]

Ok I may check them one more time would it also cause the boat speed to be that slow. What if the plugs are in the correct location? Could it be that the seal inside the prop be blown? Or would I have to press down the prop more down to press against the seal?

[oldjeep]

Ok I may check them one more time would it also cause the boat speed to be that slow. What if the plugs are in the correct location? Could it be that the seal inside the prop be blown? Or would I have to press down the prop more down to press against the seal?

Sure it would cause it to run slow, have no power. I've done it myself on my jeep once or twice

Seal isn't going to keep it from going over 10mph. If the prop were spinning on the hub your rpms would go high and you wouldn't get any movement. I'm assuming that your RPMs are never coming up - is that correct?

[miguelmaul]

Yes thats right my rpm or mph are not coming up i am just guessing the boat is going 10 mph its moving but real slow. I called my mechanic and he told me something about a seal inside the prop thats why I was just asking. So the only problem that you can think about is the firing order and if thats correct pretty much what else may it be?

[oldjeep]

Could also be a fuel delivery issue. No idea what your mechanic is talking about with the prop seal.

[Don S]

It has been running poor ever since I pulled it out for the summer and had it summerized.

Maybe I'm missing something here, but if you PAID to have it "summerized" and it doesn't run as good as it used to, why don't you take it back and have them fix it. it could be several little things that they just made a mistake on.

[miguelmaul]

Maybe I'm missing something here, but if you PAID to have it "summerized" and it doesn't run as good as it used to, why don't you take it back and have them fix it. it could be several little things that they just made a mistake on.

Hahaha if only it was that easy. The reason behind all that is because now i cant get a hold of him. So i am just playing a guessing game and trying to figure it out on my own which is very frustrating .

[Skid-joe]

I am wondering if the seal in the prop is in fact the prop spinning on the hub.....

Joe.

[mercs4mark]

I dont think anything is wrong with the mercruiser...the problem you are describing is it is hooked to a Bayliner

[rickryder]

The vanishing mechanic..... I see the problem right there..... I would suggest a new mechanic or get a service manual for your rig and go thru the trouble shooting section....so many reasons why your boat wont run WOT... I would recheck what the guy touched...wires plugs carb timing etc.

[miguelmaul]

I am wondering if the seal in the prop is in fact the prop spinning on the hub.....

Joe.

That is what i read on another forum i just dont know where to start to check that or the steps to fix that. Any help would be great. Thanks.

[oops!]

uh.....im thinking cracked manifold here....

look for a crack, about middle of the manifold.

if you do all the electrical checks....and find nothing.....and cant find a crack.....pull the manifold and pressure test

[oops!]

I dont think anything is wrong with the mercruiser...the problem you are describing is it is hooked to a Bayliner

uh......i dont think the boat has anything to to with this specific problem.

btw......there is no such thing as a bad boat........just a bad owner......

a properly cared for bayliner is still a joy to own !

[Don S]

once I get it going I put my throttle all the way forward and it only does about 10 mph or less.

What are the rpm's doing at 10 mph or less, are they low, or are they going really high?

[fat fanny]

Take everything into account previously mentioned along w/ checking to see if your distributor cap is cracked aand or installed improperly could also be a bad plug wire or plug. If you suspect a prop issue make the hub of the prop w/a marker and run it under load and as DonS mention about rpm's watch and see if it's pushing allot of rev's and going nowhere. Besides that coner the mechanic with boat in tow ride by his shop when he's open and have your rig with you make address the issue! Get what you paid for!!

[miguelmaul]

What are the rpm's doing at 10 mph or less, are they low, or are they going really high?

The RPM and MPH are reading zero but I can hear my engine revving up.

[Don S]

Sounds like a spun prop hub if the boat moves slow at low (around idle) rpm. Or, if you can smell burned rubber when you speed the engine up, it's the coupler, not the prop.

[oldjeep]

The RPM and MPH are reading zero but I can hear my engine revving up.

So in addition to whatever that problem is - your guages are not working either?

[miguelmaul]

Sounds like a spun prop hub if the boat moves slow at low (around idle) rpm. Or, if you can smell burned rubber when you speed the engine up, it's the coupler, not the prop.

Ok i have not been smelling no burn rubber yet. I also checked my hub partially and everything looked fine. What would be the steps to inspect all that.

[oldjeep]

Pull the prop off - turn it upside down and take a picture. A 2004 is going to have a flo-torque hub same as what is on my boat. There is a square plastic insert that sits inside the hub of the prop, it'll be pretty much melted if it has been spinning.