85 120 HP evinrude can't get full power,rpm gage wont work,

[steve@wv]

1985 120 evinrude,sn G1025123,when I go to WOT to plane boat out there is no extra power as in the past,I have to get someone to sit in front of the boat to get it to plane,at one time I could go 55 mph,now all I get is 35 mph,I dont here that extra voroom when I full throttle.<br /> Also my tach jumps around and does not work most of the time.I checked for loose conections at the tach,not sure were to check at the engine,I do know that my voltage regulator/altenator is bad because my battery does not charge, but is a good 12 v,Stator tested ok,could this be causing my other problems?

 

[The Marine Doctor]

Re: 85 120 HP evinrude can't get full power,rpm gage wont work,

Your voltage regulator runs your tach aswell.<br /><br />As for the other problem..down in power...do a compression and spark check.<br /><br />TMD

 

[steve@wv]

Re: 85 120 HP evinrude can't get full power,rpm gage wont work,

thanks for the info,i replaced my regulator and that took care of charging and rpm guage.<br /> I still have problem planing ,compession is 100 to 110,spark is good ,at one time i could reach 50 mph very quickly and my rpm would be around 5600 now at 5600 rpm i only get 35 mph,the boat continues to speed up to get this speed but wont lift up and plane out quickly as before the get up and go is not there,<br /> also could my prop be a factor,it is allum. and has a few mior knicks?

 

[OBJ]

Re: 85 120 HP evinrude can't get full power,rpm gage wont work,

Steve....if the engine is still turning 56k rpm, then something else has changed. An engine problem would most likely be indicated by a drop in rpm. But yours, by what you posted, are still where you are used to seeing them.<br /><br />If the prop has nicks, get it rebuilt. Is the rig takin on water? Give the set up a good once over. Something is dragging you down. I could be wrong here (wouldn't be the first time) but from your post, I don't think it's in the engine.