1990 FourWinns Horizon 180 Top Speed

[kschnebly]

I have a great 18' Four Winns Horizon with a 5.0 HO Cobra I/O with a 4.3 OMC outdrive. The boat runs like a top. I just picked it up and thought that I would be running mid to upper 40's at least when running WOT. Sadly, I am hardly pushing mid to upper 30's. The engine RPM's are staying under 4000. I have an aluminum prop that is 14 1/4 x 19p. It has a few knicks and dings but isn't too out of shape. Am I wrong to think I should be getting a better top end speed? It has a hole shot that is excellent. Any advice would be helpful. Thanks,

 

[Bondo]

Re: 1990 FourWinns Horizon 180 Top Speed

I have a great 18' Four Winns Horizon with a 5.0 HO Cobra I/O with a 4.3 OMC outdrive. The boat runs like a top. I just picked it up and thought that I would be running mid to upper 40's at least when running WOT. Sadly, I am hardly pushing mid to upper 30's. The engine RPM's are staying under 4000. I have an aluminum prop that is 14 1/4 x 19p. It has a few knicks and dings but isn't too out of shape. Am I wrong to think I should be getting a better top end speed? It has a hole shot that is excellent. Any advice would be helpful. Thanks,

Ayuh,.... Welcome Aboard,... Try a Smaller prop,... Ya oughta be turnin' 4400/ 4800 rpms,...

Yer drive is for a V8, 'n yer tryin' to spin it with a V6,.....

Ideally, you'd re-gear to a V6 ratio drive,...

 

[thumpar]

Re: 1990 FourWinns Horizon 180 Top Speed

Is the engine a 5.0 with a 4.3 drive or the other way around?

 

[NYBo]

Re: 1990 FourWinns Horizon 180 Top Speed

a 5.0 HO Cobra I/O with a 4.3 OMC outdrive

What exactly does this mean? I read it to mean that you have a 5.0L V8 motor hooked to an outdrive from a 4.3L V6 but Bondo sees it as just the opposite.

Either way, I agree with him: You aren't reaching the proper WOT RPMs for some reason. It could be the condition of the prop, the pitch of the prop, or a problem with the motor itself.

 

[kschnebly]

Re: 1990 FourWinns Horizon 180 Top Speed

Is the engine a 5.0 with a 4.3 drive or the other way around?

Sorry for the confusion. I have a V-8 Ford Engine and a 4.3 drive Not sure why they arent' the same but the serial tag on the OMC drive says 4.3. Thanks for the help.

 

[Slip Away]

Re: 1990 FourWinns Horizon 180 Top Speed

For a 1990 H180 w/5.0L V8. Top Speed is listed at 47-50 mph spinning the stock factory prop 14-1/4" x 21p.

You can look up the Fast Facts for your boat yourself.

http://www.fourwinns.com/upload/Documents/Catalogs/1990/FastFacts_1990.pdf

 

[Starcraft5834]

Re: 1990 FourWinns Horizon 180 Top Speed

I would think a 5.0 engine turning a 19p at less than 4K WOT, means engine power problems, or your boat is very heavy.. (wet foam), if the prop is dinged up/thin, that's usually going to spin faster, causing excessive RPM beyond the top end range... check engine compression first, if ok, look for waterlogging....

 

[kschnebly]

Update: problem was an engine power issue. I found that I had a faulty wire in my harness and my coil was only getting 4v. I added a new wire to the ignition and installed an internally resisted coil and now she runs 44mph at 4500 rpms. Thanks for the help from everyone.