Exceeding Manufacturer Recommended HP

I have a quick queston for the outboard motor experts on this forum.

The transom on my pontoon boat says Maximum HP is 90 but manual states it can hold up to a 300 pound engine.

If I were to put a 125 HP engine on the transom, but the weight of the motor is only 300 pounds would that be ok?

The boat is a two toon and 24 feet in length by 8 feet in width. The current engine is a Force 50 and it weighs right at 150 pounds. The Force 125 I would like to put on it is 300 pounds.

Thoughts?

Re: Exceeding Manufacturer Recommended HP

Correction... the 50 HP motor is 188 pounds, so it would be a 112 pound difference.

cjsongs81 said:

I have a quick queston for the outboard motor experts on this forum.

The transom on my pontoon boat says Maximum HP is 90 but manual states it can hold up to a 300 pound engine.

If I were to put a 125 HP engine on the transom, but the weight of the motor is only 300 pounds would that be ok?

The boat is a two toon and 24 feet in length by 8 feet in width. The current engine is a Force 50 and it weighs right at 150 pounds. The Force 125 I would like to put on it is 300 pounds.

Thoughts?

Click to expand...

Re: Exceeding Manufacturer Recommended HP

Weight is only one factor. Torque is the other. A 125hp will put a lot more stress on the transom than a 90hp. Even if your transom was brand spanking new...I wouldn't put a 125hp on there.

It's both a safety thing and a liability thing.

Re: Exceeding Manufacturer Recommended HP

Two parts to this problem thatI can see.

First it's not just the weight of the motor that counts but the force it can apply to the transom. A 125hp can push a lot harder than a 50hp. The boats I have seen have a weight and a max hp rating.

Second problem is a legal one. If there is an accident or someone is injured your insurance company may refuse cover. If the boat is not insured and you finish up in court it could effect your chance of defending the case.

I looked into this for my boat here in Australia. My year of manufacture had a max hp rating of 75hp. Later models were rated at 90hp. The manufacturer had strengthened the later models so couldn't re rate mine. I could get my hull strengthened privately but I would need to have it surveyed by a marine engineer. Very expensive and difficult to find an engineer who would do the survey. I finished up leaving it as it was as the fish don't care how fast I go.

Re: Exceeding Manufacturer Recommended HP

exceeding rated hp is actually illegal in some states.

Re: Exceeding Manufacturer Recommended HP

The difference in weight could be a 4 stroker or a 2 stroker.
They weigh a lot more than the 2st.
Follow the recomendations.
You could be liable for damages to your passengers.

Re: Exceeding Manufacturer Recommended HP

Thank you to everyone for the quick responses. We are going to stick with the 50HP engine and look for a 90HP engine and go HP as opposed to weight on transom.

We do not want to hurt anyone on the waters or break any laws.

Thanks again to all the responses. I really appreciate it.

C.J.