Fuel

[Rich976usaf]

Gentlemen, thanks for all the prevoius threads very helpfull!!

Ok Evinrude 1985 115hp vro. Just bought this motor over the winter cheep. Rebuild the lower unit seals cleaned bearings and water pump. Rebuilt the carbs. Changed solenoid gaskets (leaking). Here is the problem. Starts right up, first crank when its cold. Idles fine.

However I have to have the red solenoid valve about half way open to maintain RPM at idle. If i close the valve (clockwise) the engine REVS HIGH out of control. If i open the valve it dies out. I have disconected the lines going from primer to carbs (proper working, fuel when valve open). I am starting to think its the VRO??? The primer bulb does not get rock hard after 4-5 pumps, Havent seen any fuel going into carbs when i primer bulb it alot. I think there is a pin hole in the diaphram????

VRO pumps are expensive. Does this sound right to all you experts of the boating world. Any suggestions and help would greatly appreciated!!!! Please help. Tomorrow I am going to buy a new external tank and lines and re-plumb the vro to eliminate the possibility of leaks. I am also under the impression that there is no rebuild kit for this motor.

F-16 Crew Cheif Veteran.

 

[Dhadley]

Re: High idle solenoid controlled

Re: High idle solenoid controlled

The VRO (fuel / oil) pump is fine and doing what it's supposed to do. There is a reason the motor idles high, probably a linkage problem. When you open the primer solenoid partway you're letting a small amount of fuel go directly into the intake. That's basically (partially) flooding the motor. That in turn brings the r's down.

If the fuel pump wasn't working, opening the primer valve (solenoid) would have no effect at all. The primer solenoid only releases fuel that's under pressure in the line. If the VRO wasn't working, there'd be no pressure.

Let's go back to when you rebuilt the carbs. Did you release all the linkages and reset them all? It wouldn't be unusual to find the vertical linkage between the 2 carbs is holding one of the throttle butterflies slightly open. Or that the cam follower is touching the roller at idle.

In fact it's possible that at some point, when the carbs needed rebuilding, that someone had advanced the linkage to compensate for dirty carbs so it would idle. You've fixed the carb problem and if you didn't reset the linkage, it'll idle too high. BTW -- describe "too high".

The other thing is to look at the timer base. Make sure it moves with the throttle arm. Perhaps it's not going all the way back. Or even disconnected.

 

[Rich976usaf]

Re: Fuel

Hi thanks for your help, Ya the last thing i want to do is change the vro, ok to answer you the linkage is completely good, both butterflys completely closed, checked and rechecked linkage. i know the vro is working to some extent (fuel pressure)
Back to carbs if there still gummed up then why would i get a high rev situation? can fuel starvation cause this.....i guess this is the question. any more advice is welcome. too high rpm checked by ear, but i think i know the sound of a reving motor. if i disconnect the solenoid it revs to 3-4 k rpm.

 

[Rich976usaf]

Re: Fuel

one thing im thinking is there is alot of AIR in the filter bowl, can this cause a problem.

 

[Dhadley]

Re: Fuel

With the throttle cable disconnected and the arm back aginst the stop, is the roller touching the cam follower?

Disconnect the linkage between the 2 carbs.

Make sure the timer base is all the way back.

Does it still idle at 3K?

 

[Rich976usaf]

High Rev at idle

High Rev at idle

yes with linkage disconnected, and the roller backed off the problem still exists.

see the thing is that its reving fast with the butterfly closed, and the solenoid now disconnected, how can it rev fast if its fuel starved, that makes no cents to me???

I think i should call a priest.... Banish this evil demon

dhadley thanks, and i am trying to kill the duplicate thread... but i will keep this one....

 

[Rich976usaf]

Re: Fuel

ok, so i just was about to pull the carbs for the third time when i noticed that the timimg advance was not against the backstop, this stopped the rev problem, i know the linkage is not right, it was not tight enough, there is some play, so then i noticed there was only a drip of watter coming out of the telltale, so i droped the lower unit, the inpeller is fine, what i want to know now is the propper way to link both the throttle and the shifter, and why there is nop watter comming out of the water pump.

 

[iwombat]

Re: Fuel

Could be your tell tale is just clogged. Run a piece of wire up and see if that helps.

 

[Rich976usaf]

Re: Fuel

problem solved, today was very successful, but long. I dropped the lower unit to check the water pump, its fine, the telltale was clogged by a leaf. The shift problem was cause by my failure to properly adjust the shift rod height. so i dropped the lower unit again to readjust to 22.85". the rev problem was caused by the throttle linkage was also off. the timeing advance was slightly farward and the primer valve helped to flood the engine and compensate. thanks everyone for all the help. love the evinrude they run for ever.