WOT and acceleration issues!

[jemsoccer]

The boat: '95 Bayliner Capri 1850

The motor: 3.0LX Alpha One I/O

The problem:
I was out boating the other day and everything was running fine. About 20 minutes into our fun, I noticed we just weren't going as fast as we should have been. WOT rpms were only 3K. We slowly made our way back home and I began investigation.

The details: At WOT, the engine sounds like it is missing and does not reach over 3K rpms. It seems to idle fine, and cruises at low speed fine. Quick throttle can sometimes cause backfire, and I can hear the carb sucking in air (not sure if that is normal). The choke seems to be partially closed when cold, once warmed, it is completely opened. The carb was taken off and inspected, but the thing looks brand new inside. This motor has low hours on it and is very clean.

Other issues that may be related: Prior to the WOT issue, if you throttled to about 1/2 throttle, the boat would sometimes just bog down and die. If you threw it to WOT, you could bypass this issue and be on your way. Not sure if that helps with diagnosing or not.

Any help will be greatly appreciated. I'm just very angry that the dam thing decided to break before a week long spell of 70-80 degree clear sky weather!

 

[Don S]

Re: WOT and acceleration issues!

List of possible causes of low WOT (Wide Open Throttle) rpm.

In no particular order

Engine Won't Reach Operating RPM. Check

1. Fuel condition. Type and Octane possibly old fuel
2. Propeller pitch or diameter, damaged blades
3. Restricted fuel pickup tube or anti siphon valve Fuel System Test
4. Crankcase oil volume, high oil level can cause aerated oil and lifter collapse
5. Marine growth on hull and outdrive
6. Wrong gear ratio in outdrive
7. Restricted carburetor air intake (clogged flame arrestor)
8. Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive
9. Poor cylinder compression Compression Test
10. Carburetor defective, or wrong type.
11. Fuel pump pressure and vacuum
12. Boat overloaded, improperly loaded, or improperly trimmed.
13. Engine Overheating
14. Engine timing and ignition system operation
15. Remote control cables and linkage for proper travel to open throttle plates fully.

 

[jemsoccer]

Re: WOT and acceleration issues!

List of possible causes of low WOT (Wide Open Throttle) rpm.

In no particular order

Engine Won't Reach Operating RPM. Check

1. Fuel condition. Type and Octane possibly old fuel
2. Propeller pitch or diameter, damaged blades
3. Restricted fuel pickup tube or anti siphon valve Fuel System Test
4. Crankcase oil volume, high oil level can cause aerated oil and lifter collapse
5. Marine growth on hull and outdrive
6. Wrong gear ratio in outdrive
7. Restricted carburetor air intake (clogged flame arrestor)
8. Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive
9. Poor cylinder compression Compression Test
10. Carburetor defective, or wrong type.
11. Fuel pump pressure and vacuum
12. Boat overloaded, improperly loaded, or improperly trimmed.
13. Engine Overheating
14. Engine timing and ignition system operation
15. Remote control cables and linkage for proper travel to open throttle plates fully.

Thank you, I did find this list and only a couple may be the issue. I was hoping for more specific troubleshooting advise or even better, someone who had the same experience and could let me know what worked. I will work on this list tomorrow and suggest these issues to my local marina when I get it there.

 

[Bondo]

Re: WOT and acceleration issues!

Ayuh,... It sounds like a Fuel Delivery Issue,...

 

[achris]

Re: WOT and acceleration issues!

When was the exhaust elbow last inspected/changed? Just had a 3.0 litre with the similar problems and it turned out to be a badly corroded elbow... The owner had stripped the carb, and done the fuel system to death. Took me all of 3 minutes to look in the elbow.. I guess that's why they pay us the movie star wages... I wish....

Chris....

 

[Don S]

Re: WOT and acceleration issues!

Thank you, I did find this list and only a couple may be the issue. I was hoping for more specific

Well, if you found the list, and only a couple could be the issue, which ones are they? Then we can concentrate on those items only.

 

[Flukinicehole]

Re: WOT and acceleration issues!

I agree with Bondo it sounds like fuel delivery. Before you take it to a mechanic try changing the filter/seperator and see if this helps. You should change them every year any way. Good luck.

 

[fat fanny]

Re: WOT and acceleration issues!

Mine showed these signs and the 1st thing was a blown head gasket and then a year later was a carb rebuild before a complete fuel system check.

 

[jemsoccer]

Re: WOT and acceleration issues!

Ok, well all that set aside, I took the boat to a local marina. They looked it over and deduced that it is a worn cam shaft lobe. One of the lifters are not moving much at all. He said it should have about 1/2 inch of travel. So their suggestion is that the cam shaft is bad, possibly caused by a tight adjustment of the lifters and would cost 600-1000 to fix (including new cam, gaskets, and lifters). Does this seem about right? They took the valve cover off and watched the lifters not move.

I will probably pick up the boat and replace the cam myself, then have them do the adjustments to the lifters to offset the cost. Any opinions? How hard is it to do this? Where is the best/cheapest place to get these type of parts?

 

[Don S]

Re: WOT and acceleration issues!

Where is the best/cheapest place to get these type of parts?

Which do you want, best or cheapest. They aren't found in the same box. You can have one or the other.

Before you look for any parts, take the engine apart, I mean cam out crankshaft out, pistons out, and inspect everything. With a cam lobe gone, all that metal had to go somewhere. I would bet all the bearings are shot.

 

[Bondo]

Re: WOT and acceleration issues!

Does this seem about right? They took the valve cover off and watched the lifters not move.

Ayuh,.... That's Never a Good thing,....

It'll probably be Cheaper, in the long haul to Long Block it....

Like Don said, All that Iron went somewhere,....

 

[jemsoccer]

Re: WOT and acceleration issues!

Yea, I'll need to look at the cam and see how much or if any is gone. The mechanic didn't seem to think I'd have any issue with metal shavings, though it was discussed. I won't be able to really look at this till next week because I'm trying to get my project car on the road for a race this weekend.

What are your opinions on just having them do it vs. me doing it? I have never messed with a boat motor before, so that will be all new to me, but I am no stranger to messing w/ motors and as long as I find a good manual, I'll be OK to do the work...

 

[jemsoccer]

Re: WOT and acceleration issues!

Ayuh,.... That's Never a Good thing,....

It'll probably be Cheaper, in the long haul to Long Block it....

Like Don said, All that Iron went somewhere,....

Correction: they said only one lifter was not moving, so the cam is not completely jacked, but metal is still a concern.

 

[Don S]

Re: WOT and acceleration issues!

It only takes one.

 

[jemsoccer]

Re: WOT and acceleration issues!

I agree. I'll post pics of my findings when I strip the thing down. This will be sometime next week. Thanks for the input.

 

[jemsoccer]

Re: WOT and acceleration issues!

So I pulled my motor. But now I can't get the camshaft out. I have service manual #13 that says to remove the valve lifters, and this may be a dumb question, but where the hell are they? The manual says I need to remove the rocker arm cover, rocker arm assemblies and push rods, and the intake? I removed all but the intake. Is there where they are located? Why would the intake need pulled otherwise? Sorry for the very basic questions, but I know nothing about these motors and can't seem to find any pictures or diagrams to explain this.

 

[achris]

Re: WOT and acceleration issues!

Big tin cover-plate on the starboard side of the engine block... Lifters hide in bores behind that.....

Chris.....

 

[jemsoccer]

Re: WOT and acceleration issues!

Thanks! I thought they might be behind there. So why does it say remove the intake mani?

 

[Bondo]

Re: WOT and acceleration issues!

Thanks! I thought they might be behind there. So why does it say remove the intake mani?

Donno,... Sounds like You're workin' on an In-line,+ your Manual is workin' on a V-motor...

 

[jemsoccer]

Re: WOT and acceleration issues!

Well, regardless, I removed the camshaft and one of the lobes is round, nearly no lobe to it at all. So I will pull the oil pan and clean it up real well and probably check a bearing or two on the crank to see if there is any damage there due to metal shavings.