96 20 hp evinrude. Rough mid range, hard start

[Skiptrace]

I have a 20 hp 1996 Evinrude. I have rebuilt everything in the fuel system. It runs really well at idle once running, and at full throttle as well. It is hard to start. Turns for 20-30 seconds before starting. When it starts you cannot leave it at idle as it will stall (no fun at a busy ramp!). warm it up a few minutes and it will idle with no problem. The motor will not run smooth in the mid range. It is consistent and duplicatable every time. If I were to guess I'd say one cylinder stops firing just above idle and does not start to fire again till about 2/3 throttle them is smooths out. Only other issue is if i shut engine off after running, it loses its prime a few squeezes on the bulb and I.m back in business. It will troll at idle for hours no issue. . I have tried different plugs with no change. Should I change the fuel lines? , Coil? I am not sure where to go with this.

 

[racerone]

If it takes that effort to start there is something wrong.----Outline your starting procedure.-----Possibly missing a step.-----.Possibly investigate throttle plate opening too soon .----That causes the motor to stumble.

 

[Silvertip]

Knowing what to do involves analysis. What have you done so far other than just throwing parts at the problem only to find nothing changes? So let's start at the beginning! 1) what is your starting procedure? 2) are you using the choke/primer properly? 3) A soft primer bulb is perfectly normal once the engine starts. The primer bulbs function is only to fill the float chamber in the carburetors. Once the engine starts, fuel is drawn through the fuel line -- not forced under pressure. You should not have to squeeze the bulb to restart. 4) have you checked for spark on both cylinders? 5) have you rebuilt the carbs recently and if so, was a link & sync done after that.

 

[Skiptrace]

Thanks for the responses so far. I really appreciate it. The local Evinrude dealer is too busy selling $80,000 boats to deal with me. Starting procedure: Connect gas line and prime. depress choke switch ( I can hear it engage) turn ignition key until a hear the cylinder fire ( this takes 15 seconds or so. It rarely runs after the first firing that I hear. i repeat and eventua;;y it will struggle to run. If I open the throttle a little while its trying to run, it engages the prop and also raises the rpm enough to run. I have checked for spark and at idle both cylinders spark fine. I have checked compression last year and I can't remember the exact numbers but they were close to each other and within spec. I rebuilt the carburetor, the fuel pump, and the electric choke. The problem existed before and there was no change. I solved one problem by tightening the fuel lines with real cable clamps in place of zip ties.If I figured that out earlier I would not have rebuilt any of them. Originally the motor would warm up after hard start and not start again until it cooled off. Then it would repeat after cooling. That is no longer a problem. Define link and sync if you will. There is only one carburetor on this motor, so if we are talking about syncing carburetors that's not a step that can be taken.

 

[racerone]

Do you give it some throttle when cranking it over ??-----That one carburetor must be synchronized with the timing advance.----Do you hold choke on while cranking it over ?

 

[Skiptrace]

adding throttle engages prop as they are both on the same control. choke is electric. I have tried both ways pressing it once and holding it in. What this choke does near as I can tell is inject additional fuel into the carburetor throat. There is no choke plate.

 

[Newyota]

adding throttle engages prop as they are both on the same control. choke is electric. I have tried both ways pressing it once and holding it in. What this choke does near as I can tell is inject additional fuel into the carburetor throat. There is no choke plate.

It is called an electric primer not a choke.Kill the engine when it starts to miss and look at plugs and see if there is a difference.My 1985 20hp has the manuel primer which I give a couple pumps when cold.Have you ohmed out your coils and or the plug wires??A bad plug wire can cause a miss at different ranges.Had that happen on a car once.How did you check spark?Should use a spark gap checker.You may be flooding it and or fouling plugs in the process if over priming..My 20hp was giving me fits last year at idle and starting and priming it increased RPMS and thought I had the carb. cleaned out good, but took it apart a second time and really worked on it's passages with carb cleaner and compresed air.Must of blown something out of the narrow passage and it took care of one problem.This is one of those problems that can run you in circles.With that old of a motor you could have a number of issues like I had last year.Had air leaks and it was running lean also.Keep us posted.

 

[oldboat1]

Is the red lever parallel to the primer body for running?

If you think you are dropping spark at mid range, you can try a timing gun while running. Place it where you can see it, and see if there is no flashing at some point.

 

[racerone]

Get somebody to show you how to operate your control box !!-----You should be able to give it some throttle without shifting .----Yes indeed , time to learn about the step you are missing !

 

[Skiptrace]

Thanks for the advice. SO Far: (slowed down by something called a job) I checked with the timing light and I could definitely see the misses when in that midrange on one cylinder. Plugs looked okay. coils and wires on order they looked okay but it was real obvious. Regarding the starting. I have done some research and most of the evinrudes of this vintage have a fast idle lever. Met a guy at the ramp with almost the same motor and he had the fast idle lever. Starts real easy with one of those! I have a Binnacle? mount remote control that has just the shift/throttle lever. The fast idle (throttle) cable goes into the control housing which I was able to release from the side of the boat to look at. That throttle cable never moves during the entire cycle of that shift/throttle control. There is no manual lever on the control to lift to feed more gas. IF I (engine off) push the control past full throttle (there is a detent you can feel) the throttle cable engages way out beyond full throttle and does exactly what the manual says it should do. BUt at that point, Motor is in gear and starter would be locked out. The Throttle cable on this motor seems to only be used for fast idle, as I never pushed the throttle/shifter that far on the water and the motor runs quite well at high speed. (27 MPH on a 14 foot boat). The owners manual ( i have the original) only addresses the alternative control system.

The place the throttle is connected is solidly locked and will not move until that shifter is pushed past 75 degrees in the forward direction. SO the manual tells me how to start the engine, just not using these controls. Controls are (were) riveted in at smokercraft factory but they look like evinrude controls if the parts diagrams are right.

 

[racerone]

Run to a shop and politely ask how to start that motor with that control box. !!----You may have to move the handle sideways to disengage the shift.-----Talk to somebody on your control box.-----Might be cheaper to find out how or you may end up having to buy a new starter !!

 

[oldboat1]

Pull outward at the base of the lever (hub?). On many models, that is the secret to the warm-up setting -- trans will be in neutral, and you will have some throttle advance for warm up.

 

[Skiptrace]

OK big breakthrough. Found a parts diagram for this rare as hens teeth controller. The previous owner must have lost a few pieces and replaced them with whatever he had. this eliminated the ability to depress a button at the base of the control handle and disguised the issue. I can play with it now and see that it works properly if depressed. I have ordered the parts.

 

[Skiptrace]

Installed release button and put the earmuffs on it. throttle is now accessible when starting. Starts well and more importantly I can keep it running for the 30 seconds or so it takes to settle down at idle. I replaced coils and plug wires. took it out on the water. Midrange is very good now. Not perfect but there is definitely two cylinders firing at all times and I am able to restart with no problems and not have to reprime. I want to thank you guys for the help. Your advice was spot on.