Need Help with a 1990 Evinrude

[Texasbayboat]

Wow- What a great site, I am glad I found it!

I need help with my 1990 120 HP outboard Evinrude.

Here is the story:

Father in Law gave me his bay boat. Sat for four years before I got it. He knows that I am mechanically inclined (not with boats-but with cars), so he felt I could get it running. Well, not so fast, as I am now very frustrated.

I drained the gas in the tank, and ran about three gallons through the system with an electric fuel pump that I had. I also changed out all the plugs as well, and gapped them correctly.

I re-built the carbs (all four).

Now the boat will start fine at Idle in Neutral. It will idle up in neutral fine as well. It will idle up all the way up to 5000 RPM's if I want it to.

I then drop it down in to idle to go in to gear, it will idle up in gear to about 1/4 throttle, but then act like it is bogging and will continue to do so all the way to full throttle.

If I choke it, it will run fine, and go up on plane, and run at all RPM's.

Noticed today that the Tach stopped working as well.

Where do I go from here? It has a VRO system (I think that is the right initials). It has a S.L.O.W. system on it.

A couple of questions alsol; What does the red lever at the choke control do? If I moved that around, does it do anything?

Is the SLOW system messed up? Would I be able to throddle it up in neutral if this was the case?

Is the VRO system messed up? Same question- would I be able to throddle it up in neutral if this was the case?

Coil problem?

I read something about a Diode that goes bad as a part of the SLOW system, could that be it?

HELP!! What is my next step?

 

[matt9923]

Re: Need Help with a 1990 Evinrude

check compression. what hp?
sounds could be some bad sensor but the choke think makes me think air leak. Maybe you overlooked a seal on the carbs? sounds lik eno power under load. My frein had a chevy3500 with 4 cylinders working and he tows a 4000lb trailer. So even if a cylinders out it shouldn't be that bad in less more than 1 are bad.
good luck Matt

 

[david_r]

Re: Need Help with a 1990 Evinrude

the red valve is manual choke.

sounds like you still have something in your carbs if you can use the choke and it helps.

have you tried pumping the primer bulb when this prob occurs?

does the spark jump a 7/16 gap with a good blue flame?

if you think the carbs are good and clean take some carb cleaner and start the motor and spray the cleaner around the carb gaskets...youll know if it has an air leak.

it doesnt sound like the slow is kicking on do you ahve any alarms going off?

water **** stream good?

 

[david_r]

Re: Need Help with a 1990 Evinrude

welcome to iboats texasbayboat

 

[Texasbayboat]

Re: Need Help with a 1990 Evinrude

welcome to iboats texasbayboat

Thank you- It looks like I will be here a bunch.

I have sprayed carb cleaner around the carb, and do not have any air leaks that I can find.

Does the fuel line in these boats sometimes just get to a point where you need to replace it? That is my next step I think. Maybe the inside of the fuel line is rotting and sending junk in to the carbs?

Should I have two filters on this boat? There is a canister type (like an oil filter on a car- same size), and an inline filter at the motor. Should I have both, or just one?

Compression is fine. High on all cylinders.

No alarms going off at all. The tach not working bugs me a little, is that pointing me to something else?

Yes- Pumped priming bulb many times. It is getting fuel.

I will check the spark. Thanks for that idea.

 

[jonesg]

Re: Need Help with a 1990 Evinrude

A factory service mANUAL WOULD HELP YOU IMMENSELY, THEY ARE AVAILABLE HERE AND ON EBay.


the canister filter sounds like a water seperator, you ought to pour it into a glass , check for water, its very common with boats..

whilst you cleaned the tanks, the canister filter could be full o' water.
If its old it probably is.

When you turn the ignition on does it beep once?
Its supposed to.

Dead tach could be tach, wiring or rectifier, it gets the pulse from rectifier, does the voltage at the battery show increased voltage with rpms (same as a car). Check you're getting 12 feed at the tach, I think the grey wire is signal.

If the VRO was messed up it would seize.
An air leak would cause excess oil to be injected and you'd see smoke and get fouled plugs.

I tend to think pump , unless the fuel bulb is getting sucked flat.

 

[Texasbayboat]

Re: Need Help with a 1990 Evinrude

A factory service mANUAL WOULD HELP YOU IMMENSELY, THEY ARE AVAILABLE HERE AND ON EBay.


the canister filter sounds like a water seperator, you ought to pour it into a glass , check for water, its very common with boats..

whilst you cleaned the tanks, the canister filter could be full o' water.
If its old it probably is.

When you turn the ignition on does it beep once?
Its supposed to.

Dead tach could be tach, wiring or rectifier, it gets the pulse from rectifier, does the voltage at the battery show increased voltage with rpms (same as a car). Check you're getting 12 feed at the tach, I think the grey wire is signal.

If the VRO was messed up it would seize.
An air leak would cause excess oil to be injected and you'd see smoke and get fouled plugs.

I tend to think pump , unless the fuel bulb is getting sucked flat.

I just ordered the manual. Thank you for that. I will look in to the manual further when I get it.

The beep when I turn the ignition on is working.

Not sure what you mean by the fuel bulb getting sucked flat? I pumped the bulb, and it will pump to the point of getting firm, and then it remains firm while driving the boat. If the motor is able to run fine in choke, is it getting enough fuel to the motor?

All I keep thinking is that there is an issue with the carbs. If the choke circuit is getting enough fuel, but the carbs are not, it has to be a carb issue, right? I rebuilt them, and they seem pretty straight forward, but am I missing something here? Maybe the pump is not pumping enough pressure to support all the carbs?

Fuel seperator (canister thing that looks like an oil filter on a car) is new, but I will check it for water.

Thanks for your help. I am so excited that I found this site. It has already helped me.

 

[mikesea]

Re: Need Help with a 1990 Evinrude

If it runs ok with choke.I bet you still have issues with the carbs.Be sure to totally take them apart.I cant recall if you have a looper or crossflow engine.Crossflow has 2 metal carbs,the high speed jets are located inside the brass plugs on bottof of carb bowl.Removeable with a special slotted screw driver.If you cant get them out a pipe cleaner can clean them.Be sure to soak the carbs well in a good carb solution.I have used OMC engine tuner to desolve the varnish when a carb cleaner kit was not avail.after soaking,blow through every passage with a carb spray,carb spray is not strong enough to disolve the varnish crud,its a good cleaner after soaking.I like to use good hot soapy water after the carb soak,then the sdpray and if possible compressed air.The smallest crud in a passage means that cyl wont fire.when you are choking with your eng(has a primer not butterfly choke)your shooting fuel directly into the eng bypassing the carb,thats why it runs ok.That tells me your high speed jets or passages still have issues.

 

[Dhadley]

Re: Need Help with a 1990 Evinrude

Agreed, take a look at the carbs again. Also if the fuel in the boat is 4 years old, get rid of it.

A 1990 120 is a big bore V4 looper.

 

[Dhadley]

Re: Need Help with a 1990 Evinrude

Also, if the tach quit working the water cooled regulator / rectifier probably went bad. That should be checked, it's possible the wiring could catch on fire.