1980 Evinrude wont go WOT

[Oldyellow71]

Hey Guys!! Havent been on in a year and forgot my password so I opened a new account! Anyway, I am stumped! This is my 9th outboard and can usually get them going but am stuck! This motor starts first try everytime and has the best "around the marina" idle control of all the motors I have had. She never wants to stall and purrs at low rpms. The problem comes when I pass the no wake buoy. It will not go over 2500 rpms, she just hiccups until you throttle back and then purrs again. THis is what I have done personally, checked compression, all 3 cyl are at approx 130, got brand new tank and line, and new fuel pump. I just bought this boat and it came with receipts for carb rebuild (within 4 months), new stator, cdi, and rectifier. The electronics are visibly new stickers and plastic are perfect!! All 3 cyl have strong spark and will jump about half an inch to the water jacket bolts!! So, I have no idea what is wrong, any ideas?

 

[Monte1961]

Re: 1980 Evinrude wont go WOT

Take a spray bottle with mixed fuel and when engine starts to act up, spray or fog the carb/s and see if it helps makes it worse? This way we will be able to if its fuel issue or something else. Post back results.

 

[Oldyellow71]

Re: 1980 Evinrude wont go WOT

Thanks, sounds simple, but havent tried it yet!! I cannot figure this thing out! It has good comp, tilt and trim and is in good shape, so I want to fix it!

 

[Monte1961]

Re: 1980 Evinrude wont go WOT

We need to figure out if it's a fuel or electrical issue. Post back results. Good luck.

 

[Oldyellow71]

Re: 1980 Evinrude wont go WOT

Hey guys, I tried spraying fuel mix in thr throats to no avail! At least at idle the sparks seems strong!! Any other ideas? Does anyone know if a 1980 75hp evin has a SLOW mode?

 

[Monte1961]

Re: 1980 Evinrude wont go WOT

Ok the next step if that didnt change anything, take a inductive timing light with you and and when it acts up check to see if you have good strobe or weak intermentant spark. Post back. NOTE: Cheack all plug wires while testing!

 

[Oldyellow71]

Re: 1980 Evinrude wont go WOT

Hey guys! Have an update, I suspected a weak coil since everything seemed perfect at idle, just not at wot. I have done the carbs twice now, and the bulb trick and spray bottle trick have no effect on the rpms/speed. So I bought a coil and put it on the bottom cyl since it had the "least blue" spark at idle. It now planes out, but should go faster!! I would say I hit 30mph now, that is off feel and the gauge on the boat. not gps. btw tried to test spark on the lake with the cover off, but it stalls once you put it in gear with the cover off, is that normal? When I put the cover back on she starts first try and takes off! I thought that was wierd.