96 Evinrude 25hp 3cyl starting issues

[WhiteRice]

Well, for those that may remember my issues from a few months back, I finally got this thing running well (well, after a $800 power pack and re-working the head seals for a total of a little over $1k).

Have had it out on several occasions and was even able to use it here in several Houston neighborhoods after Harvey to help get people out. Has been running great and putting me on some great fishing.

I have run into two small issues though and my service manual is directing me to the owners manual (which I don't have) for one of the issues. First of all, my idle has become VERY high lately even though my mixture screws are near perfect. This has increased my idle speed as well which is making me a little too fast for driving through the neighborhood canals. I'm basically having to "choke it out" a little to slow me down. This is also making it more difficult to dock. Issue #2 is intermittent starting problems (rope start). I have had days where it will start on the first pull after a few weeks of down time and sometimes it takes 10+ pulls after it's been running strong all day. Just seems like this thing is going to be my "Donkey" and do what it wants, when it wants. Just want a little more confidence with it. Any ideas would be great.

 

[oldboat1]

got remote throttle and shift cables? (throttle cable could be slipping or need adjustment). Throttle idle stop would be at the end of the twist grip, and may have been misadjusted with use.

Let's see, if problem when in gear, could be a prop issue from running into debris in the rescue work (good work you did, btw....)

 

[WhiteRice]

Thanks Oldboat. It is remote and now that you say that, it does "lunge" into gear coming from neutral. Not sure what type of adjusting to do with the cables but I will read through the service manual I bought and see what's in there.

As to it being problematic in gear... the motor runs great and gets on plain quickly. No issues with cavitation either. Skeg got a little banged up but I re-worked that pretty well and the prop is in decent shape (no major couges or cuts).

My major concern is the intermittent starting issues. Just wish it would start consistently with 1 or 2 pulls.

 

[James R]

I dont recall what the carb set up is on your motor but starting problems and high idle smacks of lean mixture at idle.
When were the carbs last stripped, cleaned and rebuilt.

 

[racerone]

Has 3 carburetors.------Are the low speeds mixtures set per the dimension in the book ?----You might consider using a primer instead of the choke flappers.

 

[WhiteRice]

All three carbs were cleaned about 3 weeks ago and low speed adjustments were to spec as listed in the service manual (ran all the way in and then backed off to proper MM gap from the carb body). Ran great for a few days and then the high idle began. I am leaning more towards an air leak in a gasket because I did not replace the gaskets when I cleaned them and I will get occasional back fires at idle speeds. I was told the carbs were rebuilt last year prior to my purchasing this boat but I suspect one or more gaskets may be failing as I just noticed a slight fuel leak at one of the bowl seals yesterday while doing a pre-check. Going to order three rebuild kits and see if that solves it. A freshly rebuilt carb never hurt anything anyways.

I may have discovered the starting issue as well. For the cold start for this motor, it states to place the High Idle lever on my controls at 75% full and to be at full choke for start. I was not activating my High Idle during my start procedure. Tried starting it several times at different intervals in my test barrel a couple of days ago and doing this allowed it to start without issue (after 2-3 pulls at most which is a hell of a lot better than 10+). My thought was that this step was for Cold Start only but apparently that's what this motor wants at every start. I envy you electric start guys... lol

 

[James R]

If you cleaned the carbs but did not rebuild with new kits that was a naughty no no. Still sounds like lean mixture to me.

 

[oldboat1]

Sounds like starting technique which is now corrected -- but agree with James R that the mixture needles might be set just a bit lean for cold starting (but fine for running when warmed up). On my 9.9, it's easy to just tweak the needle a little richer for cold starting, then set it back for running. Not so much on yours.

That motor might benefit from a primer system, like suggested above (prime for cold starting). Short of that, you probably just need to get the choke/throttle procedure down to a science for cold starting. Sounds like you pretty much have it.

 

[WhiteRice]

Well, spoke way to soon and "The Donkey" got stubborn again this weekend. Got to the ramp, went through my new cold start procedure and started right up on the first pull. Idle seemed fine this time around and once I was out of the neighborhood channels I opened it up and took off to our first fishing spot (about 10 min at WOT). Fished for a bit and it started to rain. Rained lightly for about 30 min and then it stopped and the fog moved in. We were using the trolling motor mostly as we were in fairly shallow salt marsh water. Decided to move to another spot and motor started on first pull again. At this point the fog was getting more dense so I throttled down to 1/2 for about 20 min. Water began to get choppy on the open bay and I decided to head back to the marsh to avoid any fast traffic since it was so foggy. Did a 180 and as soon as I throttled up, it sputtered and died. Could NOT get it to restart for anything. Removed cover and checked lines, fuel bulb, throttle cable, checked for spark, etc. and all were in order that I could see.

Kept cover off and tried to start again. At this point, I am seeing a slight "spitting" upward of fuel originating from behind my powerpack when I was pulling the rope (yup... a few drops of fuel were spitting straight up from a source I could not see). At this point I also notice a small pool of milky, white fuel at the bottom of the motor under the carbs. I squeeze the bulb a few times and sure enough, I have milky, white fuel over-flowing from my top carb (actually spitting from the side over flow opening and from the carb mouth at the silencer). Luckily this whole time my wife was guiding us in with the trolling motor and we made it back in to the ramp ok. Loaded the boat up (this was fun with a trolling motor BTW) and headed out.

Had to work yesterday and today so I haven't had a chance to break things down but milky, white fuel is fuel mixing with water somewhere, right? Tank lid was tight and I do not have a separator. Fuel bulb is new and the line from the tank to the motor is fine. Is it possible that the humidity was mixing with the fuel at the possible compromised carb seals? I'm also assuming that the mystery fuel "spurt" from behind the powerpack is a vacuum line that has come loose and could this be another factor for mixing?

 

[racerone]

There are a few wee recirculation hoses behind the powerpack.-----The way they go on is not covered in manuals.------Time to replace those hoses.

 

[WhiteRice]

Thanks Racerone... I'm assuming that they will be basic vacuum line that I can replace those hoses with...? Any ideas on the water intrusion into the fuel? I'm assuming that's why the fuel was white and milky...?

 

[WhiteRice]

Ok... To update what I've done and the results I've had:

I removed the power pack to expose all of the re-circulation and vacuum lines that were discussed earlier. Took a pic of the way they were routed and removed one hose at a time and replaced one at a time. Most of the hoses were cracked at the ends. Replaced them all (5 total) and re-assembled everything. I then rebuilt all 3 carbs from scratch with new rebuild kits. Cleaned them all thoroughly and re-assembled. Filled my flush drum and "The Donkey" fired right up on the third pull following my new cold start procedure. I had my idle screws almost all the way out so it would start high then adjusted them slowly (15 sec increments between adjustments) until the motor started back-firing. I then slowly back the idle screws back out until I got a nice, consistent idle. I let it run like this for about 20 minutes and then shut it down.

Five days later (this morning) I wanted to for it up to do a double check of everything because we are going fishing in the a.m. Filled my flush drum, tired to start it and nothing. I tried making some slight adjustments to the idle screws out, took off my air silencer, double check the vacuum / re-circ lines and even pulled the plugs to check for fouling. Everything looked good but it just would not turn over. Probably tried to start it about 40 times. Had plenty of fuel going to all three bowls, had my wife come out to double check I was getting spark on all three cylinders (I was) and tried starting again... Nothing.

In frustration, I removed the spark plugs and did a few pulls with the ignition off (maybe it was flooded or something... I have no idea) and then replaced the plugs. I switched the ignition back on, pulled twice and then it fired right up! Now I know that pulling the rope with the spark plugs out would be much easier since there is no compression but could I possibly have a clogged exhaust that is causing too much back pressure for a consistent start? The only reason I ask is simply because the motor's "feel" when pulling it plugless felt very similar to when it is a warm start (very easy pull). Any other time I have a cold start the rope is VERY tight. Almost like trying to pull start an old lawn mower. I get LOTS of smoke at initial start up and I have a normal (at least what I have been told) amount of mixture coming from the exhaust while its running.