Last 2 years my rig does not like to get on plane in this hot weather. Have regular 100 hrs. maintanance done.The last time was this past weekend at Amistad, motor was banging out and would barely run 50mph. The prop is merc tempest 27 pitch.I have had it in the shop for this before and they cant find anything wrong.Any suggestions.

Sounds like you need to take one of the plugs out in your prop.

go with the Fury 25P no plugs best prop on the water

What RPMs are you getting? The hot weather will slow the motor but it sounds like something else is going on. The 27 is good sized but shouldn't be a problem for the 250 to turn. What was the motor doing when it was running well?

(motor was banging out and would barely run 50mph) This is not the prop it is a coil or a powerhead base gasket leaking.

Sounds like ethanol got your fuel lines.. Mine did it not long ago and changed lines and fuel canister and it runs fine now..

Ask Tommy Yetts at Rockwall Marine. He is on this post.
He can fix anything, nice guy, and above all else he is frugal with spending your money!!!

Coil

Powerhead issue. It should be covered under warranty.

if it is not running right why continue to run it outboards will not fix themselves if it is not right running it like this will compound the problem take it to a pro good luck.

Definitely get it looked at before something serious happens. After you get repaired you may still want to go down a inch or so in pitch for the hot humid summer. We are seeing a big power loss in these big motors these days due to the ethanol and hot temps. You can lose up to 20% horsepower.

I have had in the shop when it does it to me ,but when i leave it with the the mechanic it never does it to him. Plus has ran a scan on the compuer and no codes.Just wondering if anybody else had similiar proplems.thanks for advice

Coil Coil did I say Coil

Ithink I get it 007.