Loss of power

[Ross333]

I have a 1986 Advance.  I just took it out of storage and was out for about an hour and it started to run a little rough.  Then I couldn't get it to go above 15 mph or so.  The engine sounded rough with some knocking etc.  The engine generally sounded rough.  The strange thing is when I take it out of gear and rev the engine it will rev up to 3500 rpm or so (didn't try to go higher) but as soon as I put it in gear it won't go.  My first thought is that the gas in it is bad.  It has the gas from last year in it with some stabilizer but I haven't put new gas in it yet.  Any thoughts would be greatly appreciated. 

[Messer]

Ross- I'm no mechanic, but- I had a similar situation a few years back. Now granted the fuel stands out but I've stabilized fuel in the past had have not had the same issue some had when dropping her in the lake after 5 months of storage when it coms to bad gas.  Anyway, my issue was I had just left my boat with a local shop to convert to an electronic ignition. I was away in the service but upon return home on leave I put her in, ready to go. She ran like, what we call in Alabama, a pulp wood truck (pup wuud). Meaning, pulp would trucks are trucks with 500k miles and last tuneup at 60k. She slugged through the water occasionally spinning good and attempting plane, but then dropping back. Wide open throttle resulted in about 17-20kts with occasional backfire.
Diagnosis- bad conversion parts to electronic ignition (which you may have to check your distributer, cap, rotor and or similar parts if electrionic). After I got a new kit and installed it, she ran, and still does, great. Upon de-winterizing I usually have to pump the throttle couple of times to ger her fired, then it is a simple turn key and fire.

[backfoot100]

I'd start with a good old fashioned tune up. Points, plugs, cap, rotor and maybe wires depending how they look. When was the last time that was done?

I don't think the gas would be a problem as long as stabilizer was added at storage but when did you last replace the fuel filter/water seperator? If that hasn't been done recently, I would change that too.

Then let us know how it runs.

[Joel]

Yep... both the guys above are on it...  I had the same issues and thought it to be bad gas.  Turned out the metal contact inside the top of the distributor cap had fallen out and was pinging all over the place.   Took a while to find & get the correct distributor cap 

Report back on what you find!

[Ross333]

Ok so sorry for the delay on reporting back.  So I replaced the fuel filter in hopes that by some miracle that could be the only problem.  That didn't really do much of anything.  It seems to rev a little better in neutral than it did before I replaced the filter but that could just be my imagination.  Here is some more information about what is going on with the boat.  It has a rough idle and will eventually die.  When I put the boat into gear it will go to about 1000 rpms but then anything after that it doesn't want to go at all.  I drove for about 1o minutes with it at around 1500 rpms and it felt like every once in awhile it would get surges of power.  Nothing major but it felt like a little more gas was getting to the engine.   I also pulled the engine cover off and looked at the carb while under load.  The 2 primaries seem to be working fine (I don't know much about carbs) but if I understand correctly the secondaries won't open until a higher rpm.  I guess my next step is to pull the boat out of the lake.  As recommended by previous posts I may need to do a full tune up.  I don't have a lot of experience with engines but have found that given some guidance I can figure out most problems.  Is a tune up something I should do myself or is it best to take it to a shop and have them look at it?  I know that a tune up may not solve my problems especially since it seems to be fuel related but it may help.

Ross

[RonT]

Full tune-up is still the correct starting point, if convinced its a fuel delivery issue then an anti-siphon valve inspection  would follow a tune-up.

[Ross333]

So I replaced the spark plugs and took it out and she ran strong for about 10 minutes or so.  Then I heard some knocking and miss firing and now it isn't as bad as before but still not running well.  I guess points, cap, condensers are next?

[Ross333]

Just replaced the distributer cap as I see I have a aftermarket electronic ignition system.  I believe it said petronix?  Heading back out to see how she runs.

[Joel]

My bet is its the distributor cap...  Where did you get the new one?   Mine is a Petronix and has the screw down type distributor & cap.

Joel

[Ross333]

I went out for a quick cruise and that seemed to fix the problem.  I got new distributer cap at a place called n3 boatworks here in Indy. They are a pretty big correct craft dealer and happened to have some parts that fit my boat.  Thanks for all the help guys! 

[backfoot100]

It's amazing how many problems can get fixed with a good old fashioned tuneup but guys always want to overthink it.

By the way, N3boatworks are really good people. If you worked with a guy named Zach, he's a frequent poster at CCFan. Lots of parts on different marine engines are not brand specific.

[Joel]

Joel drives the lane... its up... and... HE SCORES!!!!   

[Ross333]

Yeah I'm pretty sure I over thought this one.  Yeah Zach is who helped me over at N3.  Very helpful! 

[Ross333]

Alright well now I'm really confused.  So I ran it yesterday for about 45 minutes.  I pulled a few skiers and it seemed to be running fine.   Then it lost power again and was fighting hard once I got into the 2000 rpm area.  It seemed to get progressively worse.  Started out that it took longer to get on plane than it did the first few times then it wouldn't get above 2000 rpms.  I heard some knocking and some miss firing as well. 

[Mike Harry]

Did you move the distributor by mistake while installing parts? Sounds like it may be out of time.