1990 johnson 90 HP still low power

[funfisher]

Changed plugs and checked all fuel and replaced all plastic clamps with stainless and new fuel filter. engine idles good and revs good in neutral. pulled plug wires one at a time, rpm dropped on each one. ran ten minutes on hose rechecked plugs, three looked a little oily, one really bad, started up again, rechecked that plug, rpm still drops when I pull the wire put old plug on the wire could see spark when I touch it to head.<br /> Engine is way down on power under load WOT then back off to atleast half before engine starts to slow. Tried choke at WOT almost killed it. Runs alot better with cowl off, not great but better,<br />butterflies are all the way open at full throttle.<br /> I'm at a loss. Any suggestions appreciated.

 

[Dhadley]

Re: 1990 johnson 90 HP still low power

Be very careful with the stainless clamps. They can cut the hose and cause a leak over time.<br /><br />Good luck!

 

[petryshyn]

Re: 1990 johnson 90 HP still low power

>check timing<br />>check compression

 

[funfisher]

Re: 1990 johnson 90 HP still low power

I will have to borrow friends timing light.Do I check one number one plug wire, and is 28' BTC optimum?<br />Thanks for the replies.<br /> <br />P.S. My tach quit working at the same time. Could this be a sign of an electrical problem or maybe just coincedence?

 

[petryshyn]

Re: 1990 johnson 90 HP still low power

The link/synch requires several checks. You need a manual. A very good investment......<br /><br /> manuals

 

[funfisher]

Re: 1990 johnson 90 HP still low power

I would love to buy a manuel, cant figure out which one actually covers '90 model 90 horse johnson. Do you know?

 

[funfisher]

Re: 1990 johnson 90 HP still low power

I would love to buy a manuel, cant figure out which one actually covers '90 model 90 horse johnson. Do you know?

 

[Down South]

Re: 1990 johnson 90 HP still low power

I think th emanual is the 5th one down on this link. Good luck<br /><br /> http://www.boatdealers.com/mall/ind...0116&current_category=johnson outboard manual

 

[funfisher]

Re: 1990 johnson 90 HP still low power

Hello again,<br /> I bought the seloc manuel and with a little trouble shooting came to the conclusion that the rectifier was bad since the tach. quit working and the battery isnt charging. The stator ohms out good. Replaced the rectifier last night and put her on the water. Guess what ,no change.<br /> This manuel is a little vague since it applies to so many motors and years.Is there anywhere I can get a manuel specific to my motor. It is a 90 model 90hp Johnson model# TJ90TLESB<br /><br />Thanks,<br />Teddy

 

[Bear]

Re: 1990 johnson 90 HP still low power

Is it a looper?<br />7) '89-'95 4 Cylinder Looper units: <br />If the engine misses on one cylinder with the white/black temperature wire hooked up and does not with it unhooked, this is usually the timer base causing the problem. <br /> <br /> http://outboardparts.com/troubleshooting/troubleshooting6.htm <br /><br />How about the fuel pump? Did you squeeze the bulb at any time at wot? Maybe it's time for a fuel pump kit. Revving in neutral is one thing. Revving under load requires more fuel.

 

[funfisher]

Re: 1990 johnson 90 HP still low power

I think its a cross flow. Tried squeezing the bulb while at WOT didnt help tried choke at WOT didnt help. Does run a little better with cowl off still not good. Tried moving timer advance at WOT (just with slack in linkage didnt adjust setting) didnt help.<br /> Is there any way to test a tachometer? Im not sure if mine is dead or a symptom of the problem.<br /><br />Thanks,<br />Teddy

 

[funfisher]

Re: 1990 johnson 90 HP still low power

^