Boat will not plane at all and RPMS won't come up

[davis80lm]

Ok. I've got a 1989 Four Winns Horizon 170 with a 2.3L Ford coupled with an OMC outdrive.<br /><br />The boat has a fresh tune-up and the carb was remanufactured. The boat also has a hydrofoil on the outdrive.<br /><br />All was good until the carburetor gummed up on me. The boat planed very quickly and ran like a top. Well I got the carb reworked and changed no settings whatsoever. The boat started right up and idled perfectly at my house and it would rev freely up and down and find idle. I figured all was well in my boating world again but I was wrong.<br /><br />It idles fine in the water but as soon as I try to go WOT under load I can't get the boat past 3000-3200 RPMS and my speedo won't even register I'm going so slow. The bow is almost pointing straight up and I'm kicking up a monster wake. Before hand the boat would run on plane at 4200 RPMS and around 30 MPH (speedo indicated, not accurate I'm sure)<br /><br />I cannot figure out what is wrong with this thing. It's stored on my trailer so the hull isn't dirty. I had a coworker suggest that I may have gotten water between the hulls and I should be able to find a plug or passageway between the hulls back in the transom. I haven't been able to find anything like that as far as plugs go, but the boat isn't sitting any further down in the water that I have noticed.<br /><br />Someone also mentioned that the prop could be slipping in the hub so I swapped my propeller and will be testing that this weekend. I don't see this as the problem since my RPMS cannot climb up and with a spinning hub I would think that the RPMS should shoot up with ease.<br /><br />Anyone have any ideas or things that I could try? I really want to enjoy the last month or so of the season.<br /><br />Thanks in advance.<br />Dennis

 

[craze1cars]

Re: Boat will not plane at all and RPMS won't come up

My first guess is that you maybe didn't get the carb reinstalled properly, and your controller/throttle cable is simply not opening the throttle all the way.<br /><br />Crank the throttle wide-open (engine off!) and look at the position of the butterflies (not the choke...look deeper in the throat), they should be wide open.<br /><br />Second guess is that if your carb gummed up, maybe so did your fuel filter(s) and/or fuel pump.<br /><br />Not sure what else you have already checked, but I'd start there.

 

[vipzach]

Re: Boat will not plane at all and RPMS won't come up

I am with craze, double check your carb install and then replace your filters, check the pickup tube and the anti-syphon valve. I really doubt your prop is slipping, like you said the rpm's would shoot up and the boat go nowhere! Something with that reman carb may not be set correctly.

 

[Bondo]

Re: Boat will not plane at all and RPMS won't come up

Well I got the carb reworked and changed no settings whatsoever.

I'm Sure that's atleast Part of the Problem............<br /><br />There's No Way a carb can be Rebuilt,+ Not Retune it when it's Installed..........<br />That's what 1/2 of the Rebuild is All About...........<br /><br />Wether it's Just the carb Settings,..... Or Other Issues in the Fuel System,.........<br />Your motor is Starving for Gas,..... That's Why it refuses to Pull UnderLoad......<br />What it'll Rev to without a Load is Totally Irrelevant........<br /><br />These Guys have given you the Places to Look,......<br /><br />Good Luck........

 

[Sagabu]

Re: Boat will not plane at all and RPMS won't come up

I agree w/all above .<br /> When I do a rebuild on a carb, I always replace the fuel filter.<br /> I bench set the air mixture screws by turning them all the way in and then backing them out 2.5 turns.<br /> This generaly puts them in the ball park.<br /> I then use a vacume gauge to fine adjust them to maximum vacume at a 1200rpm idle on the gauge and listen for the smoothest idle to ballance them turning them no more than 1/4 turn at a time each.<br /> Then I back down the idle and shoot down the lake.<br /> I always recheck after running it abit so the engine/carb has time to adjust to the reset.<br /> The vacume gauge is my best friend when timing and tuning an engine.<br /> Vacume = Power !<br /> I have also experienced a trim problem that caused a somewhat similar issue once. The trim would not hold in the up position and would work its way back down under presure.<br /> Under full throttle and trim up watch to see if the trim is bleeding off.<br /> Just stabs in the dark but easy to check.

 

[davis80lm]

Re: Boat will not plane at all and RPMS won't come up

Thanks very much for the speedy replies guys. I'm going to get out on the lake today and try to make adjustments to the carburetor. I had put a brand new filter/water separator on right before I had the carb rebuilt, but I do have another one here so I'll just go ahead and put it on. No sense in not changing such a cheap part to make sure that's completely ruled out.<br /><br />Thanks again, I'll let you know how it goes.

 

[trebor0301]

Re: Boat will not plane at all and RPMS won't come up

Heres one for you.My buddy at the docks did a carb rebiuld and when he put everything back together he had the same exact problem as you.It turned out to be the throttle cable was reconnected wrong.When he put the throttle all the way down it actually was only moving the throttle on the carb about 25%.You might want to pump the throttle while watching how the linkage is responding at the carb.