OMC goes in gear, no power during acceleration

[acolman99]

I have a 93 Four Winns Horizon 190 with 190 HP OMC Cobra I/O. It has been a very reliable boat although not used much over the last two years. I am a relative newbie to marine tech but I have and can repair almost anything mechanical. Just haven't had any experience in marine repair.

Just put the boat in the water for the first time this year and everything went as normal until I got a ways away from the ramp and gave it some gas. As it accelerated, the engine appeared to 'disconnect' from the prop as it revved and the boat slowed. At idle, the boat propels properly in forward and reverse, but as soon as you accelerate it stays at the same speed. No strange noises - just seems like the prop is slipping - like a clutch slipping on a car. I tilted the stern drive up and put it in gear (with motor off) and the prop was tight on the shaft, but of course I couldn't really turn it with a lot of force by hand.

I just got back home and was reading my shop repair manual and see the prop has a rubber hub and says 'an underwater impact may loosen the rubber hub and cause the prop to slip'. I also see there is a clutch for engaging the forward & reverse gears on the prop shaft. I don't know how old the prop is as I have only owned the boat for about 3 years.

Anyone had this problem before? If so, how can I test if it is the clutch or the prop? Anything else can cause it to act like this?

Thanks for any insight to tell me what to check next.

 

[regalbrad]

Re: OMC goes in gear, no power during acceleration

This same thing happened to me yesterday. Luckily, we had some friends out with their boat, so they towed us in. Otherwise, it would have taken a long time to get back in to shore. We have a 1993 Regal 202se with the mercruiser 4.3 and it is doing the same thing you describe. I hope someone has some insight for us.

Brad

 

[danond]

Re: OMC goes in gear, no power during acceleration

Cobras are notorious for the lower shift cable causing similar shift engagement problems. If left unchecked the issue can destroy gears.

Based on the age of the boat, if you can't recall when the lower shift cable was replaced, you're probably due. It can be $75 in parts that saves you thousands.

It would also be wise to pull the outdrive off and take a look inside. Check out the driveshaft splines, align the engine, check out the u-joints, gimbal bearing, driveshaft bellows and engine coupler. All required maintenance/check items if you don't want to get stuck out on the water again.

The drive is easy to pull - 7 nuts and it comes off. Only need 2 seals to put it back on.

If your prop hub is spun, you can sometimes turn the prop with your hands while the drive is in gear (engine off).

Also - don't run the drive in gear with it in the up position. That's a good way to chew up the u-joints and rubber bellows!