1997 90HP Evinrude

sbump52

Petty Officer 2nd Class
Joined
Feb 5, 2008
Messages
115
Just bought a boat with this motor on it. Is it a looper or crossflow? How to tell difference? Previous owner mixed gas, no VRO. Did it have it? Glad it doesn't. Anything I should be particularly aware of from this motor? Seems to idle good and runs good on the test drive we took today. Any help is appreciated. Thanks. By the way, you guys helped me with my first project a 1955 10HP that now runs great. I hope to have the same kind of motor from this motor. You guys are the best.
 

sbump52

Petty Officer 2nd Class
Joined
Feb 5, 2008
Messages
115
Re: 1997 90HP Evinrude

Ok took it out for my first trip this afternoon. Motor ran great, but noticed the tach would reach about 5200 rpm's at WOt and then slowly go back to 0. When I would slow down, the tach would come back up again and when back at WOT it would go back down to 0 again. What would cause this issue? Also, seems like the fishfinder would stop working also.
 

McGR

Senior Chief Petty Officer
Joined
Jun 19, 2004
Messages
664
Re: 1997 90HP Evinrude

In '97 Evinrude made both crossflow and looper versions of the 90hp. The crossflows are the older design 90 degree V4 motors and the loopers are 60 degree V4s. If you can see the flywheel on top of the motor, it is a crossflow. The loopers had plastic covers over the flywheel.
 

sbump52

Petty Officer 2nd Class
Joined
Feb 5, 2008
Messages
115
Re: 1997 90HP Evinrude

Thanks for the reply. I can see the fly wheel so that let's me know. Any ideas on the tach issue?
 

archcycle

Chief Petty Officer
Joined
Sep 21, 2009
Messages
647
Re: 1997 90HP Evinrude

Get behind the gauge and check every wire going into it. Take them off one by one checking for corrosion and replacing the ring terminals if they are corroded, and then snugly reattach it. Solder any new connectors! The liquid paint on electrical tape is also great for these kind of things. Then work back from each wire plugged into the tach to make sure they are in good shapeand the thing that side plugs into is in good shape. Check for obvious corrosion on butt connectors joining cut wires. This really sounds like a bad electrical connection. Check everything back there thoroughly before you even consider replacing the tach.
 
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