Help Troubleshoot - Low Power Four Winns

[LS1Steve]

Hey Everyone,

I have a 1989 Four Winns 200 Horizon 5.8 liter V8 w/OMC Cobra. The boat has been in the family since day 1, but used very little... Has 40 hours on it!!! Engine bay looks mint!

Anyhow, I took possession of it last season, took it to a mechanic to have it checked out. He gave it a tune-up, serviced the drive, adjusted/inspected everything and it was good to go. Took it out last season and it seemed to be fine, but low on power. Throughout the day, it got worse. I had 7 people, but that boat should handle that fine as it always has in the past. By end of day, boat was not even able to plane. Started/idled/ran very smoothly otherwise, just wouldn't rev out. Seemed like a fuel starvation issue.

I've pulled the fuel attachment at the carb and checked the screen - all clear. Pulled a plug, and while they are old, no corrosion. Wires also old but seemed fine and correctly placed. Again, I think this is fuel related. It was on a fresh tank when the issue started.

I'm mechanically inclined and tune my own cars, but boats are not my specialty.

Anywhere you guys suggest looking first? Any 'easy' stuff to check before I take it in to the mechanic? I traced the fuel line from the holley carb (carb looked clean as new) back to some module, which I didn't even know what it was... a pressure regulator of some sort? Any tips would help greatly.

 

[HT32BSX115]

Hey Everyone,

I have a 1989 Four Winns 200 Horizon 5.8 liter V8 w/OMC Cobra. The boat has been in the family since day 1, but used very little... Has 40 hours on it!!! Engine bay looks mint!

Anyhow, I took possession of it last season, took it to a mechanic to have it checked out. He gave it a tune-up, serviced the drive, adjusted/inspected everything and it was good to go. Took it out last season and it seemed to be fine, but low on power. Throughout the day, it got worse. I had 7 people, but that boat should handle that fine as it always has in the past. By end of day, boat was not even able to plane. Started/idled/ran very smoothly otherwise, just wouldn't rev out.

Howdy,

Welcome aboard!

Well, there's quite a few reasons that could cause low WOT. Have a look at http://forums.iboats.com/forum/engin...rch-version-of

Focus particularly on #15 there's quite a few "things" to check there!

Cheers,

Rick

 

[Scott Danforth]

if you have only 40 hours on a boat that is 28 years old, you need to use the boat more often. that is just a bit over 70 minutes a years.

sitting ships go to shi#

 

[JJBoatr]

My brother had a similar issue with his 92' Four Winns 180 Freedom w/4.3L. Problem was one of the main jets was clogged in his Holley 2 bbl. The boat would run and idle good but would only hit 35mph. After he cleaned the jet it was back to normal power reaching 47mph as it should. Might be worth looking into once you check all the simpler stuff.

 

[LS1Steve]

Some updates here....

Again, issue was sluggish acceleration on my boat, worse toward end of day. I think this ended up being an 'easy' issue to solve (famous last words).

Took it to mechanic, he could not find anything wrong at all. Checked everything he could think of and idled it for a while and couldn't see what would cause the issue. We agreed to just have him change the fuel filter and I'd take it out again and report back.

It mostly ran fine. Got up to 45mph (2 people in boat). Accelerated ok. I did notice one thing going on that I believe may have been the culprit, and I'm not sure how I didn't notice before. It seems to be filling the bilge with water pretty quickly. I needed to run the bilge pump pretty much the entire time in the water. When I shut everything off and open the engine hood, I can hear water coming in, sounds like a small water fountain running.

Should the drain plug have teflon tape on it? I had it in there pretty tight, and while maybe its not a complete perfect seal, didn't seem like water should be leaking in that readily. I think before, I hadn't had the bilge on so often, and maybe the sluggishness from before was just a heavy a$$ end filled with water. I did look at the water level and didn't see it too high but maybe just didn't notice, and before I had about 8 people with coolers and gear.

Could there be a transom seal issue here? What seals should the mechanic check on? There was a very audible flow. If I lost the bilge pump I'd be scared.

Side issue - after getting it back, it idled worse than before. It was very smooth idle before and now I have a +200-300RPM surging that happens about every second. The engine shakes during the surge. Any ideas there?? Maybe he messed with the timing? Vacuum?

 

[southkogs]

Water should stay outside the boat You need to find your leak. Could be an engine thing, could be a structure thing. You need to identify which it is. You're seeing water in the bilge, but you've got more hull that's invisible to you where there could be more - and surely that can mess with the performance of the boat.

Find your leak. Put the boat in the water, and look around for where the water is coming in.

What type of plug do you have? It shouldn't need teflon tape regardless, but I'm assuming you have the screw in type. If so, you need to make sure it's screwing in tight and holding water out.

 

[LS1Steve]

Welp, mechanic took a look and says the 'transom plate' has a big leak around it. Normally he'd suspect wood rot, but since the hours are so low and boat was so well kept, we suspect that when the transom was replaced (with a refurb unit many years ago) that it wasn't tightened down enough. Unfortunately the boat was in the water only a couple times since, so we never got to test it much. Motor has to come out to access all the bolts and re-tighten. Bring On Another Thousand.

 

[HT32BSX115]

Welp, mechanic took a look and says the 'transom plate' has a big leak around it. Normally he'd suspect wood rot, but since the hours are so low and boat was so well kept, we suspect that when the transom was replaced (with a refurb unit many years ago) that it wasn't tightened down enough. Unfortunately the boat was in the water only a couple times since, so we never got to test it much. Motor has to come out to access all the bolts and re-tighten. Bring On Another Thousand.

Yes. the drive must be removed, the engine removed, and the transom tightened.
Then the engine is replaced, you do an alignment and the drive is finally replaced.[all in that order]

Before I would tighten the transom though I would remove the transom mount and inspect the wood in the "hole" just so I could be satisfied the transom is NOT rotten.......Otherwise, it's not worth trying to re-install the engine and drive.

 

[Lou C]

Two things
One a common cause of lack of power or lack of ability to plane out the boat that is often overlooked is the anti siphon valve on the gas tank. Did the mechanic check this? I had this same problem on our boat about 15 years ago and that was the cause.
The other is the water issue if this boat was hardly used and the drive shaft bellows was never replaced it could be all dried out and cracked letting in water. Remove the drive and inspect.

 

[LS1Steve]

Boat is back. He pulled the engine and drive and re-tightened the plate. Exhaust was also very loose and contributing to the leak. Anyhow, no more leak! Hopefully it performs better now. Bring on another thousand! Wood looked perfect, very strong, lots of life left in this vessel.

I'm going to do a plug change for good measure, since I think it has the originals, which actually don't look terrible. WISH I'd had him do this with the engine out, ugh. To the best of my research, Champion R15YC4 is the right plug, despite my wanting to find a 'better' premium plug.

I've been reading about octane levels too, and believe it has 91 fuel in there. Is that actually hurting the power? I really need to check my timing to confirm it is advancing right. But from what I've read, I should be using 87 or could suffer some mpg and power loss.

 

[HT32BSX115]

I've been reading about octane levels too, and believe it has 91 fuel in there. Is that actually hurting the power? I really need to check my timing to confirm it is advancing right. But from what I've read, I should be using 87 or could suffer some mpg and power loss.

Power output is not related to octane (alone) . Increased octane is for increased anti-knock properties.

Some earlier model OMC engines did have timing settings that would allow advanced timing to produce slightly more power. In that event, the service manual indicated that IF using advanced timing, you would need to use increased octane fuel to prevent detonation.

You really do not want to do that since not all lakeside fuel suppliers will have 91 or higher octane fuel. Many of then only have 87 octane. If you were timed for using 91 octane, and filled it up with 87, you could damage the engine severely if you had a detonation event

Running an engine on 91 octane that is timed for using 87 is just a waste of money. It's not going to hurt anything though.

Also, ensure that your mechanic did do an engine/drive alignment when he re-installed the engine. If he just pulled the engine and bolted it back, (and didn't align) you'll eventually be pulling the drive and engine to replace the coupler.

Regards, ,

Rick