2000 90 HP no Rpms

"My boat sat up for a year, C

"My boat sat up for a year, Cleaned Carbs, Replace Fuel line and Bulb, New Fuel, It will Rev to 5300 on Trailer or in Neutral, However in Gear and Under way will only Rev to 3000. No Missing or skipping No smoke, like loading up just no Revs, Has same prop as Last year Not overloaded, Any Suggestions?"

"I could be way out but have y

"I could be way out but have you done a compression check? A friend had a similar problem, would rev up but give hardly any power in gear. After lots of looking turned out he had a cracked piston which a compression check should have revealed.

You could also try removing the HT lead off a spark plug one by one and seeing if that makes it worse. If the same I would look into doing a compression check on that cylinder."

"Thanks, Will give it a try?

"Thanks, Will give it a try? Have pulled Plug wires one at a time and it does make a big difference. It doesn't seem to be missing its like the Butterflies are not opening fully? but they are."

You have to start at one of th

You have to start at one of the engines systems and begin troubleshooting. The only short cut to this is the WAG approach.

"Have good compression 140 ac

"Have good compression 140 across the board, Had carbs cleaned ck'ed spark engine runs fine, cranks right up no missing ,Stalling, smoking, Etc, will run Around 3000 all day just not above Just thought someone had ran into this?"

I've run into it thousands

I've run into it thousands of times...The procedure to determine the cause is the same. You pick one of the engine's three primary systems and start troubleshooting. Sometimes you get lucky and the cause will reveal itself right away. Sometimes you spend hours determining the odd reason. Generally you start with the fuel system and start your testing there. Think of it like this:

You have a stomachache...The potential causes are endless. The likely cause is a reaction to something you ate.

There is no automatic cause. Just potential causes. Look at your fuel system and branch out from there.