Maiden Voyage....FINALLY!!!

Gangly

Seaman
Joined
Jan 3, 2013
Messages
68
I have a 1991 Four Winns Horizon (22'-23') with an OMC 350 and Cobra drive. It has taken me 6 months but I finally got everything (shifter cable, gaskets, carb, distributor, etc) replaced or working, minus the interior, and took it out on the lake this past weekend. The lake was CHOPPY with all of the boats on the water and the waves were an honest 3 feet sometimes. Made for a rough but fun ride.

Now for some questions:
1. When driving the boat in these conditions (3' waves), maximum speed was around 35 mph when registering 4500 rpm's, is that normal?

2. Max RPM for the motor is listed around 4500rpms. However, I hit it good once and I looked down to see the gauge indicating 5700 RPM's and rising fast when it only sounded like it was around 4,000. The boat was still pulling hard and gaining speed easily. However, I immediately shut it down and got it running around an indicated 3,000 RPMs based on the in dash tach. Granted a gauge is more accurate than my hearing, but working around and bulding multiple engines with a large portion of my life dedicated to racing, the gauge seems to be waaaaay off based purely on my hearing. Are the in dash tachs prone to inaccuracies?

3. Will these motors easily pull past the 4500 RPM and make it to 5700+ rpm? Not that I will ever try to do it, I dont want to take the motor past its recommended redline, i am just curious if these motors will easily spin past that number if you arent careful and paying attention. Just to be sure, is there a rev limiter on the motor or a throttle stop that keeps you from revving the engine too high? If not, is there an aftermarket one available?

Ill take an auxiliary tachometer with me next time to verify the rpms, but it just seems odd to me that the rpms sounded much lower than what the tach showed as well as my top speed being so much lower than expected while at the indicated maximum rpm's. Especially considering the motor so readily rev'd past the indicated 4500 with the boat responding so well to it.

4. While the drive was off, I adjusted the shift cable using the tools required. It went great and the drive shifts smoothely. However, when i shift it into forward or reverse while on the water, I hear a very soft clunk. I dont feel it at all, I cant sense it through the hull or shifter or anything, its just simply a very soft, very quiet clunk sound that I can hear from the rear if Im listening for it. Is that normal or should you not hear anything at all?

Thanks for any and all help, I appreciate it.
 
Joined
May 27, 2013
Messages
22
Re: Maiden Voyage....FINALLY!!!

The Cobra guys will respond about the clunk, my stringer makes the same noise. Your tach is probably not right, unless the prop is in the air. There is no rev limiter unless there is a computer controlled distributor on board. I got my 350 just over 4000 rpm last night and if the water was smoother I might have gone a little more.
 

Gangly

Seaman
Joined
Jan 3, 2013
Messages
68
Re: Maiden Voyage....FINALLY!!!

Thanks for the quick reply.

The motor was trimmed down between 1/4 to 1/2 trim and was definitely in the water.

Does your 350 want to pull past 4000 easily or does it start to top out around there when in the water and not want to pull much past it if at all?
 
Joined
May 27, 2013
Messages
22
Re: Maiden Voyage....FINALLY!!!

If the water was smoother I would have held it wide open longer. There were some small white caps just starting to show. There was still more rpm to be had just on another day. Speedo read close to 50mph in my 18ft Seaswirl Sierra.
 
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