1995 four winns 5.0 sxs running out of umph

maxhighlife · **Joined:** Sun Feb 05, 2012 5:54 pm **Posts:** 6

I have a 1995 four winns 200 horizon 5.0 cobra "50faphue" assumed 190 hp with sxs drive 1.60.1 propped with a ss 14.25X21p it was converted from efi to a eldelbrock 4bbl and it runs good but will not top 35 mph and 4000 rpm I feel it should run 50+mph and pull a ski or wake board the throttle is responsive I don't feel any slippage it just runs out of torque I think it should pull the 21 pitch prop with ease but I have been thinking I may need to consider a 17 or 19 any ideals??

Walt · **Posted:** Sun Feb 05, 2012 7:54 pm

Are you sure the numbers you posted are correct? From those I show 30% prop slip. Check this prop slip calculator and plug in what you know. Make sure speed is by GPS and averaged running both down stream and upstream if applicable.

I would first suggest going through and doing the typical maint stuff.... Plugs, wires, cap/rotor, fuel filter and ensure you are running a fresh tank of good gas. This is to make sure you have a good baseline for doing trial runs on different sized props.

A 5.0 on a 20' boat is somewhat of a pooch, as I test drove one. 40-45 mph would be a reasonable top end; maybe 48 mph with your gear ratio and prop combo (51mph, 4800 RPM, 15% slip). That WOULD be sacrificing low-end for pulling skis/boards and having passengers. As you have 190 HP and expecting 50+ MPH, my boat is only about 1' longer, with an additional 130 HP and I can only do 50MPH turning 5200 RPM.

maxhighlife · **Joined:** Sun Feb 05, 2012 5:54 pm **Posts:** 6

I have new autolite plugs, new 8mm wires, dist. cap, rotor button, new carb, fuel pump, filters, removed and cleaned tank, all new fuel line, 93 octane fuel

I use the term slip more referring to cavitations or something not as a tech term I’m not really familiar with slip % calculation??
When I stab it i’t feel like it grabs good just not like my other 115 johnson on my 17 ft fish and ski and it wont get over 4,000 rpm unless I trim it up to where it blows out or hops very bad

Walt · **Posted:** Sun Feb 05, 2012 9:31 pm

That's a start. Is this a new issue, or something that has been for some time?
Did the old plugs look OK? Fuel Pressure OK? Timing/Advance (no more than 8 deg IMO) Maybe even try opening the fuel cap to be sure you are not drawing a vacuum on the tank.
Trim should be about 1/3 of the way up, but looks like you are already familiar.
Have you verified the tach is reading correct?
4 bbl carb.... verified both sets of butterflies/T-stat operating correctly. If it's a 750 cfm carb, may be dumping too much gas into the intake resulting in too high fuel mixture (had that on a buddies 327; likes 600 cfm much better).

Hope that helps.

LouC · **Posted:** Sun Feb 05, 2012 10:23 pm

I think you are too high in pitch, I know that the 200 Horizons of my boats generation (88-92) came with a 14.5x19 on the V8s and a 15x17 on the V-6s. Mine had a 14.5x19 when I got it and it wouldn't pull max rpm either, but when I changed to the 15x17 it easily pulled 4700.

Borchik · **Posted:** Mon Feb 06, 2012 7:12 am

If it sounds like its running ok but you just arent getting there I would check timing first and if thats good then go with a prop change. If it was fuel it would more than likely fall on its face once the fuel in the carb bowl ran out or ran low. If you havent checked the timing do that first.

maxhighlife · **Joined:** Sun Feb 05, 2012 5:54 pm **Posts:** 6

im running a 600 cfm carb and I cant find the timing mark on the block by the harmonic balancer to refence the light I have it set just a tad high when the engine is hot I shut it off and crank it and it has just a little hump or starter drag but there’s is no octane knock or pinging under hard load

ric · **Posted:** Mon Feb 06, 2012 9:09 am

What the?? Why in god's green earth would you remove the efficient and awesome fuel injection for the world's worst made carburetor?

LouC · **Posted:** Mon Feb 06, 2012 1:21 pm

maxhighlife wrote:

im running a 600 cfm carb and I cant find the timing mark on the block by the harmonic balancer to refence the light I have it set just a tad high when the engine is hot I shut it off and crank it and it has just a little hump or starter drag but there’s is no octane knock or pinging under hard load

I looked at the parts diagrams over at Doug Russell.com

http://www.dougrussell.com look in OMC parts....

and I learned that the 5.0 in that year is a Ford engine. Keep in mind that the Ford engine used different timing marks than the more common Chevy small block. I had a Ford 5.0 (302 cu in) and the way the timing marks were set up, the degrees were on the harmonic balancer, and there was a pointer on the block that you used for reference. On the Chevy, there is a tab with degrees on it on the engine by the timing chain cover, and there is a notch on the harmonic balancer that you mark with paint. On my Ford, I marked the timing mark on the balancer with paint so it would show up and then aligned it with the pointer on the engine. I don't know if the newer Fords still used that system, but in the OMC shop manual I have, the Ford 460 was used in that time period and the timing mark set up is exactly the same as on my old 1970 302.

maxhighlife · **Joined:** Sun Feb 05, 2012 5:54 pm **Posts:** 6

RIC,
I got the boat for free the guy could not find parts for the efi and had someone put Quadra junk Rochester on it and when you launched it fell on its face so I had the bright ideal to use a eldelbrock and it now runs good just not as good as it should

LouC
Thanks for pointing that out I didn’t think to look any further I will check that tonight

LouC · **Posted:** Mon Feb 06, 2012 2:29 pm

LOL, I am surprised that I even remembered that, my parents bought that car ('70 Ford Torino, 302 V-8, C-4 auto trans, Ford 9" rear axle) back in '76 and the last time I saw it was back in 1986 or so, I had given it to one of my brothers and it got rear ended and he gave it to a friend, still ran...

Anyway, there are two things about timing that you have to make sure are right for the engine to run properly and pull max rpms. One is base timing which you set at idle, the other is total timing advance, which is measured at a specified rpm. To do that, you need an advance timing light, and have the boat in the water. You need to have the boat in the water because you cannot usually run it that fast on the water hose, the hose can't keep up and the engine may overheat. So you are running it in Neutral, with the boat securely tied up a the dock, or on a mooring. I did mine with the boat on our mooring, got some funny looks from young'uns who don't know what a timing light is, LOL...
You make sure first the base timing is right. Then you set the throttle at the specified setting (usually its 3000 rpm or so) and with the advance timing light, you check to see if you're getting the total you should (base timing + advance=total advance).
For example, in my OMC manual, for a 5.0 Chevy, the base timing was 10* BTDC, at about 3200 rpm, centrifugal advance is supposed to be 12* for a total of 22* @ 3200 rpm.
Different engines have different specs, so you need to know what the specs were for the Ford 5.0. This tells you if the distributor is advancing the timing as it should, to keep up with the speed of the engine. The distributor can use either electronic advance, or mechanical. My old 88 4.3 has a simple points distributor, with simple centrifugal advance.

If you don't know how to use an advance timing light, the light has a dial on it. You set the # of total degrees of advance on the dial, then check the timing with the engine at the correct rpm. The light should show that the timing is at zero or TDC on the timing pointer, because it can allow for the total degrees of advance.

ric · **Posted:** Mon Feb 06, 2012 2:41 pm

What he said.

I grew up around Edlebrock carbs, they are hit or miss on the setup. They normally always require re-jetting. If you would have got a Holley marine carb from a 5.0 mercruiser/VP it would have been pretty much setup perfect since the chevy/ford are same stroke/bore/displacement.

Walt · **Posted:** Mon Feb 06, 2012 3:07 pm

I want you to bear in mind the potential explosion hazard using an automotive carb versus marine....
An automotive carb can vent.... it's not in an enclosed space and such, and well ventilated. The marine carbs are different in that respect, and that difference can result in hazardous build-up of fuel vapors in the engine compartment. Can you say kablueeeee?!

Otherwise, I would agree you may be propped too tall.

LouC · **Posted:** Mon Feb 06, 2012 3:19 pm

Judging by the pix on the Doug Russell site, the carb models of that Ford engine, used what looks like a Holley Marine carb. I have a Rochester Quadrajet on my boat, it's needed to be rebuilt a couple of times, but that's probably due to the fact that the internal seals, gaskets, float, etc were not made to be ethanol proof. Once it is set up right it works fine. I also have heard good things about the Edlebrock Marine carbs too, supposed to be better or easier to set up than the Q-Jet. In any case, you have got to get the basics right first. Don't forget to check the anti siphon valve, if it's corroded and sticky, it will make the engine starve for fuel even if nothing else is wrong.

fiznuka · **Posted:** Tue Feb 07, 2012 12:04 am

I have a question what is your elevation (sea level-5200ft). I seem to have the same problem with mine if it is a problem at all. With a 14.25x17 according to the speedo in the dash and tach I had similar numbers 42 mph at 4300 rpms at around 4500 ft elevation. With a 14.25x21 prop I was at 37mph at 4000 if I remember correctly. With the new engine I built I was expecting a little more out of it so this spring I am going to change to a 19p prop. The numbers should fall into line of what the engine can do and the elevation I am at. I will run the 21p at a lower elevation the 19p for fun and the 17p for tubes and wakeboarding. I have done the timing in the water and in the driveway doesn't seem to help. Maybe I am still in the break in period but who knows. I also don't trust the gauges in the dash to many years and waves.

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1995 four winns 5.0 sxs running out of umph

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