Declining Efficiency

Try adding some startron. It helps. I add it now and then.
It's in a blue bottle, I think it is viagra for old engines!
LOL!
 
Thanks, Dave. I'll try it for the boat...and me :)

Thank you all for your input. The boat is scheduled for a tune-up on Thursday which is just in time for a nice run to NJ.

I will also be going through the boat before we take off and remove anything that isn't necessary but I think the weight of belongings is not really a variable here as we have a very set inventory on the boat (there's only so much room on a 31PC for storage and we remove almost everything every winter) and as a matter of fact I think we might be running lighter than in the past because I used to carry a dink and a torqueedo (about 100lbs total) 50% of the time and those have been off the boat since before last season but the numbers have continued their march downward (or upward depending on how you look at it).

The hunt for the magic bullet continues.
 
Great point about fogging. When I first joined BE I talked to GVP about plugs. I was going for high end plugs. George said if you fog the engine you are going waste money and ruin the the plug. He told me to go with gtandard plugs and change them annually.
 
I fog my engine every year. After 17 years I put new plugs in it. The difference was zero. Gas with 10% ethanol will yeild a 3% decrease in energy; not likey to be causing the OP to burn 33% more fuel. My guess would be more related to weight and where it's distributed as well a drag of the hull. Props could be an issue if something was hit, but for that to make sense he would have had to ding them more each year.
 
My best 'similar' was a 357 Chevvy in a 29' Boat.
11 GPH at cruise, 13-17 GPH with the throttles into the Four Barrels.
My Plugs hardly showed bad, and changing them did not help.
I think that Ethonal is your problem.

You have EFI which means your injectors might need some help. They are supposed to SPRAY! Not slop or squirt. No Drips, no Runs and no slobbers.
I'd bet the Ethanol and your Injectors are the problem.
Sorry, I've never seen an injector from an EFI, but I did see the Difference in an old VW Injector.

You could have a compression check and get a heat indication off each Exhaust manifold port to see how your engine is doing age wise, but I'd bet, if your not burning oil, your still in good shape except for fuel delivery.
 
That you need more rpm to get the same speed indicates to me that it is not engine problem. You are using more power to get the same boat speed.

The boat got heavier and you have more drag or the props are not as efficient as in the past. A prop scan shop is a good idea if the boat is sitting about the same in the water and the bottom is very clean.
 
Could be the weight is not balanced on the planing part of the hull. Something heavy moved forward?
 
These are all good points and now that we've been having this conversation I did notice that the boat is sitting somewhat lower in the bow than the stern (based on the bottom-paint lines). The only think I can think of there is that I since I made it easier to fill my water tank I probably run with more water more recently (it hold 50 gals under the v-berth so maybe I used to have only 30-40 gals and now I head out with a full 50) and I need to check the anchor locker to make sure it's not loaded with bay bottom. There's no other storage up front except for under the seats in the cabin but they are small and basically contain some snack foods and a few (really) bottles of alcohol. Then again, more recently, I have gotten into the habit of running out to my favorite destination with my wife asleep in the v-berth so that could be a factor too.

The prop scan will either be at the end of the year or mid-season if I need to pull for zincs or the tune-up doesn't have any impact.

However, I just go this from my mechanic on the tune-up: "All done and much needed. Left the old parts in the boat, check out rotors amazed port engine ran." I guess I needed to stay on top of that better.

I will have him check the injectors next unless someone tells me it something I could do myself.

I just want to say it's great having you guys weigh in on this and I appreciate the help.

Jeff
 
quote:
Originally posted by Thudpucker

Could be the weight is not balanced on the planing part of the hull. Something heavy moved forward?

Click to expand...


I'll need to hide this comment when I show my wife this thread :)
 
Thanks,Thud. I'm not burning any oil so I'll save that for last but the injector situation intrigues me. How can I check that...or is that a mechanic thing?
 
You are in a precarious position. I'd get back to blaming the props ASAP, regardless. Don't wait. Scary scary scary.
 
quote:
Originally posted by Ghost

You are in a precarious position. I'd get back to blaming the props ASAP, regardless. Don't wait. Scary scary scary.

Click to expand...


I'm not sure what you mean by this. What do you believe can occur? I confirm with my mechanic that he, at least, carefully inspected the props before re-installation and he said he had and there was no deviation from original that he could detect. I did inspect them over the winter too and they looked fine to me. As far as I know they've hit anything other than a little sand (we have a soft bottom where I boat - shallow but soft).

BTW, now I see what my mechanic meant by he is surprised that the one engine was running at all. There was a missing piece of conductor (the little flexible tab that takes the spark from the center spin) so the spark had to jump about 1/2" to make it to the rod that actually transfers the spark to the outer edge of the cap. Oy.

The plug look ok. used but ok.

1 hr run to NJ tomorrow so that will be a good test.

Jeff
 
LOL, the Injectors are a Mechanics thing. I'm told they can be tested, but dont know anything about it.

In all the boats I ever had, the prop's were never a problem. Maybe I had some of the "Lo-Bucks" models with Zero performance though. The only fast boats I ever had were I/O's where you can always see the props when it's on the Trailer.

That Anchor locker statment got me to wondering.
I had an old Chris Craft with an Anchor locker up on the bow.
When I was tearing out some rotted wood, I discovered the Anchor locker still had about 5 Gal's of water in it.
I 'relieved' the Locker problem with a Bronze Drain port.

Water weighs about 6.5 Lbs/Gal. So your extra 10 Gal's is 65 Lbs up on the bow.
 
I always thought H20 was 8lbs/gal but in any case I went to the boat tonight and the anchor locker has absolutely nothing in it (except 200' of chain rode) and is mush drier and cleaner than I could imagine. I also check the bilge area under the v-berth (where the bow thruster is installed) and it's as clean as can be...as in it's never had water in there.

The big (initial) test will be performance tomorrow with new plugs, caps and rotors. I can only hope for some improvement.
 
Something is wrong I say you have the wrong prop. Dealer or someone switch them on you, your wot should be 5200 rpm I thing this link will help you it is your motors and boat.Oh by the way I assume when your riding you have your trim tabs up and your out drives trims properly.http://www.boattest.com/boats/boat_video.aspx?ID=1394
 
http://www.boattest.com/boats/boat_video.aspx?ID=766#Test-Result This is yours.
 
you will know right away if the needed rpms are still high. When that happens think about what that means in terms of engine doing work.
 
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