93 Rude 70HP : 2500RPM at full throttle, wot in neutral

[jvaccarino]

Few weeks ago out on the water at full throttle, the engine bogged down to 2500 RPM.. thought perhaps slow mode from overheat/bad sensor.. Sensor seems to be fine, and the engine is not overheating.. I can rev in neutral full throttle, no problem. The problem lies when in gear... Is this an easy fix? I pulled the engine cover off, and I can press the throttle gear forward and the engine passes 2500 RPM.. but seems to be gear linkage or something wrong with the throttle body itself.?? Any suggestions?

 

[HighTrim]

Re: 93 Rude 70HP : 2500RPM at full throttle, wot in neutral

You could have any number of fuel system problems. But if you can only start at full throttle (not good for the motor) -- you could be dealing with flooded carbs. So the first thing you may want to check out would be the choke system's operation. Others will jump in with better ideas though,but may want to read through this while you wait, gl

http://forums.iboats.com/showthread.php?t=167352

 

[jvaccarino]

Re: 93 Rude 70HP : 2500RPM at full throttle, wot in neutral

I can start the engine no problem.. I don't have to give it gas to start it.. It's only pushing down the throttle in gear is my problem

 

[jvaccarino]

Re: 93 Rude 70HP : 2500RPM at full throttle, wot in neutral

Just a little FYI.... Hooked up ear muffs to engine just now.. and I can rev past 2500 in gear and neutral. But when the boat is in the water, cannot rev past 2500 in gear..

 

[F_R]

Re: 93 Rude 70HP : 2500RPM at full throttle, wot in neutral

STOP DOING THAT!! Yes, I am shouting. Stop revving it in neutral like that before you blow it to bits. The motor is not making horsepower because it is not running on all cylinders. Of course it will rev in neutral, there is nothing holding it back. It is up to you to find out why it is not running on all cylinders. Can be carb problem on one or more, ignition problem on one or more, compression problem on one or more. Not to mention blown piston from revving it in neutral.

 

[jvaccarino]

Re: 93 Rude 70HP : 2500RPM at full throttle, wot in neutral

I need to understand why it is possible to rev in gear with muffs out of water, but not in water.. this doesn't make ANY sense to me. To reiterate, I am not going WOT, just testing past 2500 RPM..

 

[voodoo]

Re: 93 Rude 70HP : 2500RPM at full throttle, wot in neutral

It revs in gear out of the water because there is no load, no resistance to the spinning prop. For the same reason your car on ice will spin the tires, you are not actually doing any "work". Pull your prop, put the boat in the water and watch the revs spin happily away untill you smoke the motor.