1985 Evinrude 90hp V4 low rpm at wot :( any help would be great!

SCStripers

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Here are all the details,the motor sat for 2 years before i bought it,owner completly cleaned out carbs and we went for a quick joy ride, ran great! have been using the boat every weekend for about 5 weeks. launched boat and headed to honey hole, after two hours started it up and was unable to get any rpm at wot. stopped checked plugs and one is real wet.changed plug, stil runs wet, At low idle she runs like a dream. if i pull plug wire off on that cylnd she barks and is unhappy (like my motherinlaw)so it would seem that its getting spark at idle. Now here is somthing strange, in wot with low rpm as i slowly draw back on the throttle i get about a 3 second burst of rpm or speed. (?) with a second person driving i can watch the gas spraying in all 4 carbs, the carb that has the wet plug seems not to be spraying as much fuel in the throat. I adjusted jets to 1 1/2 turns out to make sure. After reading all of the messages it sounds like a bad power pack?? or maybe a coil? I know this was a long topic but I wanted to be complete, Any ideas? Joe....will you be the man with the plan?!
 

Joe Reeves

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Re: 1985 Evinrude 90hp V4 low rpm at wot :( any help would be great!

SC.... There are no adjustable jets on a 1985 90hp Evinrude. What is the model number of that engine?
 

SCStripers

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Re: 1985 Evinrude 90hp V4 low rpm at wot :( any help would be great!

Joe.. As soon as get back to the house I will get the s\n of the engine, all info on the cover is 90hp VRO V4 (the VRO has been taken off) I mix gas and oil. Thank you so much for helping
 

SCStripers

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Re: 1985 Evinrude 90hp V4 low rpm at wot :( any help would be great!

Ok here is what is stamped on the motor. 85ETLR78C J4964854. Thanks again
 

Joe Reeves

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Re: 1985 Evinrude 90hp V4 low rpm at wot :( any help would be great!

SC.... Sorry to inform you that the engine you have (Model #85ETLR78C) indicates that your engine is not a 1985 90hp Evinrude. It is a 1978 85hp Evinrude.<br /><br />The VRO setup did not come into existence until 1984.... six (6) years later. That is why there are adjustable needle valves on those carburetors.<br /><br />The procedure for adjusting those carburetors follows:<br /><br /> (Dual Carb V/4 With 4 (2 each carb) Slow Speed Adjustable N/Valves)<br /><br />The adjustment procedure of the carburetor slow speed needle valves follows. NOTE... if the needle valves turn too freely, replace the nylon bearing retainer (the nylon item at the front of the carb that the needle valve goes through first) with the newer type RED retainer #315232. <br /><br />If your engine has that weird linkage that connects all four of those needle valves, the newer RED retainers will enable you to discard that linkage. The RED retainers make it impossible for the needle valves to viberate out of adjustment. <br /><br />(Carburetor Adjustment - 2 Slow Speed Adjustable Needle Valves, each carburetor) <br /><br />Initial setting is: All (4) Slow speed valves = seat gently, then open 1-1/2 turns. <br /><br />Facing the carburetors, start with the top left needle valve, then the top right valve, then the bottom let valve, then the bottom right valve. It may be necessary to redo these steps to get the adjustments ideally set <br /><br />Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. <br /><br />Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting. <br /><br />Do not attempt to gradually adjust all four of the valves at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve. <br /><br />When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 

SCStripers

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Re: 1985 Evinrude 90hp V4 low rpm at wot :( any help would be great!

Ok, 1978 85 horse it is...bummer but now atleast I know. So do you think that its the carbs that need attention? and not a coil or power pack? seems funny how the one plug is wet at wot. any more ideas if adjusting the carbs do not clear the problem? Thanks again Joe
 
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