Outboard Motor Performance

Actually it is the lack of performance!
I wanted to post to see if anyone else has experienced something like this with their OB?
I have a Mercury 200 HP EFI. The motor seems to run ok when up on plane at most every throttle setting. When I try to run the boat on the trailer, it performs like a 25 horse trying to push a 2000 pound boat. No Power and the motor will not wind up at all? (even at full throttle?)
We can eliminate one possible cause, that is to say the trailer is in the water!
If anyone has any ideas, I would appreciate your feedback.

Joe, you answered your own question: just hit the trailer at planing speed and you’ve got no problem!

Is it every time you goose the throttle from displacement speed, or only when loading onto the trailer? If it’s okay in open water, maybe the trailer crossmember is starving the prop? Does it ventilate when you’re loading?

Joe Have you checked your oil level ?? Jim

Alright you guys, planning speed has been considered! An interesting idea but the prop does not cavitate. The motor is under load but is way short on power. I have the engine tilted back at the trailer so it is not very close to the crossmember. I have checked the oil and the level is ok. Thanks for the feedback. Still looking.

It sounds like this is only happening when the motor is tilted up for low speed shallow running, and that this probably relates to the operating angle of the motor. A pinched gas line or throttle cable, or possibly a loose wire or a fuel pump issue?

Good luck and let us know how this turns out for you.

Dan

Has this always happened? or is it something that just started to occur?

I think Bassn Dan has the right answer. The motor will only run up to 2500-3000 RPM’s with the motor is tilted past a certain angle for shallow water use. It’s a safty feature on a lot of motors. It prevents the operator from gunning the motor and possibly tossing passengers overboard.

Jon J.

Thanks, Dan and Jon, I really appreciate the ideas, I don’t believe my motor has any rpm limiting device (other than possibly a max >6000, limiter.) The tilt angle I am using to load the boat is the same one I use when running WOT. I would like to add, I currently have the boat in the dealers shop and so far they are thinking that the exhaust tube inside the lower unit may be cracked allowing water to get too high up into the exhaust system? (that was a possibility from Mercury at Fond de Lac!) They are still looking and I am hopeful I will not have to buy a new 250XS to fix this.
Don’t you hate when no one else in the world is having or has ever had the same problem as you?
Thanks again everyone.
Joe

Chitwood…the exhaust thing is exactly what I would have guessed. The motor is choking itself off because it cannot breath out the bad stuff… so to speak. The 200 EFI that I had would do the same thing. It (the exhuast getting plugged up) was a way of me knowing that I had the trailer too far backed into the water. That big baby couldn’t breath! Imagine if you backed your truck down so that the muffler was under water…what would the engine eventually do? With the water as low as it is, we seem to have to get further back with our trailers now. Just my opinion..good luck. Hope it isn’t a cracked unit.

I think your boat just doesn’t want to go home