95 evinrude 90hp wont go full throttle

[casey2001]

the motor idles fine but when i throttle it all the way up in gear its like it doesnt have any power and moving about 10mph at 3000rpm then its like it kicks in and pushes hard for a few seconds and then it will kick down again and a little bit later it will do it again but it will never go full, fut it will in neuteral...im not sure..........can any one help?

 

[ezeke]

Re: 95 evinrude 90hp wont go full throttle

Put the control in neutral, disconnect the throttle cable, take the air silencer cover off the carburetors, and check the throttle plates.

The throttle plates need to be fully closed at idle and perfectly synchronized through their entire range. When at full throttle (WOT) the throttle plates should be horizontal.

When you are sure that the throttle plates are synchronized, return them to idle position and adjust the throttle cable until it slips on easily without moving the throttle lever on the engine, then reconnect.

If you have a warm up lever, make sure that it is off before adjusting the cable.

 

[casey2001]

Re: 95 evinrude 90hp wont go full throttle

thanks for the info i will give it a try

 

[casey2001]

Re: 95 evinrude 90hp wont go full throttle

I messed with the linkage and the throttle plates and every thing looked good, so i took it back out on the water and it still does the same thing. I throttle up and it tops out at about 10 mph and 3000 rpms it will drive like that for a few min and then something kicks in and it feels like normal and starts taking off and climbs to about 4000 rpms give or take a few and then it kicks back down it does that on and off but never gets up and goes like normal, but the rpms will climb fine in nuetral. I checked all the plugs for spark and there getting good spark and looked for any loose wires and didnt find any.

 

[ezeke]

Re: 95 evinrude 90hp wont go full throttle

What is the boat like and what is the pitch of the propeller?

 

[casey2001]

Re: 95 evinrude 90hp wont go full throttle

it is a 19ft center console and im not sure what the pitch is but its the origional

 

[ezeke]

Re: 95 evinrude 90hp wont go full throttle

Since you don't know the pitch of the propeller, my question would be: since you have owned it has it run at around 5,800 RPM and has it been getting on plane easily? In other words, is this a new condition in your experience?

 

[trendsetter240]

Re: 95 evinrude 90hp wont go full throttle

If your carbs are in synch, I think it sounds like it might be a fuel problem. If one carb is not getting fuel or is partially restricted you could see symptoms like that.

With the air silencer off and the carbs exposed start the engine and let it idle. Take a can of aerosol carb cleaner and spray into one carb at a time and observe the results. If the motor bogs down and dies that is as expected. If it revs up when you spray in that carb then you know you have a lean mixture (fuel restriction).

If one carb has a fuel restriction remove the single screw at the base of the carb to remove the float bowl. This bowl should be full of fuel.

If not full then the restriction is in the fuel line or the needle valve at the carb fuel inlet. If it is full then that carb has a clogged jet. Either result and the carbs should come off for a rebuild (cleaning and rebuild kit).

If the above checks out ok (engine bogs out when sprayed in each carb) time to check for spark on each cylinder.

Cheers and Welcome to Iboats!

 

[emdsapmgr]

Re: 95 evinrude 90hp wont go full throttle

Is this a looper or a crossflow 90?

 

[klrbruce]

Re: 95 evinrude 90hp wont go full throttle

Had a problem that sounded like yours. Started and idled good. Throttled up couldn't get out of its own way then plenty of power for a while then dropped power again. It was an intermittent coil problem. Broken wire in coil would make contact=full power, wire seperated a little=low power. Changed coils ran great...took a while to find because these type of problems are fuel related 95% of the time and coil tested fine until warmed up.

 

[kenmyfam]

Re: 95 evinrude 90hp wont go full throttle

How did you test for spark ???

 

[ezeke]

Re: 95 evinrude 90hp wont go full throttle

We need for you to do a compression test and report the results. http://forums.iboats.com/showthread.php?t=313963&highlight=compression

 

[casey2001]

Re: 95 evinrude 90hp wont go full throttle

i finally fixed the problem, i had the boat running in the yard tinkering with different things on the motor. I pulled all the plugs again to double check for spark it was good on all, so i put them back in and ran it again and while it was running i started pulling plug wires one at a time to see if i noticed a difference in the tone of the motor and i pulled the last wire and i didnt get any difference so i isolated the problem to that one cylinder i broke down and bought new coils, wires and plugs and it fixed the problem. but i dont understand why i was getting spark while the plug was outside the motor but not while it was in it.

I thank all of you guys for the information and help

thanks casey

 

[kenmyfam]

Re: 95 evinrude 90hp wont go full throttle

i finally fixed the problem, i had the boat running in the yard tinkering with different things on the motor. I pulled all the plugs again to double check for spark it was good on all, so i put them back in and ran it again and while it was running i started pulling plug wires one at a time to see if i noticed a difference in the tone of the motor and i pulled the last wire and i didnt get any difference so i isolated the problem to that one cylinder i broke down and bought new coils, wires and plugs and it fixed the problem. but i dont understand why i was getting spark while the plug was outside the motor but not while it was in it.

I thank all of you guys for the information and help

thanks casey

If you just checked for spark by grounding the plug against the head it may show good. With a spark tester it should jump a decent size gap. The spark can easily break down under compression.
That is the reason for the spark and compression responses posted above.
Glad all is now well.