Ongoing 1993 Evinrude 115 problems...

[Party hut Chris]

Ok- changed line and bulb.

Question: Bulb started drawing fuel, and pumped up hard. I squeezed it another couple of times, and I felt the fuel leave the bulb and it started drawing fuel up again. When I pump it up and it gets firm- do I stop then? I was under the impression that it needed to firm up and stay that way...

In any event- engine started right up and ran for about 5 minutes strong. I had to turn it off and leave, so I don't know if it had enough time to burn off the fuel that I had pumped in...

 

[racerone]

The purpose of the bulb is to fill the carburetors with fuel.----When carburetors are full and there are no major leaks the bulb will go hard as no more fuel can be pumped in.---The bulb has done it's work.----The bulb does not stay hard once motor starts !!!!------This primer bulb is used so that the starter motor does not need to overwork to do the same thing.---And on a manual start motor the bulb saves your arm muscles from having to crank the motor over while fuel pump fills the carburetor.-----This is because 5/ 6 gallon outboard tanks are often run empty as they are not equipped with a gauge.--Also outboard often sit longer than daily driven vehicles.

 

[Party hut Chris]

ok- so if i chase the overheating line...where should I be able to place my hand?

 

[SparkieBoat]

on the top of the head, just above the spark plugs.

 

[racerone]

Most important check is compression.---Have not yet seen compression values posted !!!---Not sure why this simple test is not being done !

 

[Party hut Chris]

recerone- two simple reasons: 1. RAIN, and 2. I'm having to do this on the water, and anytime I've been out, there has been HEAVY traffic on the lake. We're in a terribly unprotected location, and the waves are awful when I'm down in the motor compartment.

I am hoping to be able to get there tomorrow afternoon, get the plugs out, and check the compression.

 

[Party hut Chris]

Racerone and all experts! Compression test has resulted in the following: (Not sure of proper terminology).
Port lower: 120
Port upper: 110
Starboard lower: 120
Starboard upper: 100

What do I have going on?

 

[racerone]

Remove bypass cover on the low compression cylinder.-------Just 6 wee bolts and you can have a look in there.

 

[emdsapmgr]

If the compression is within 10%, it's considered normal. Your compression is outside that "normal" range. Agree, further examination is warranted. Removing the bypass cover is one easy way to check the ringsets. You may need to pull the head on that side. You could do a decarb of the engine, using some factory Engine Tuner. Compression may come up a little. It's a good periodic maint procedure for these crossflow engines.

 

[SparkieBoat]

you can do a decarb with some seafoam that may help if you just have sticky rings. search" decarb seafoam"

 

[Party hut Chris]

Ok, so haven't really had the engine running since changing the fuel line and primer bulb, so I went out this morning to start it up and do a seafoam treatment.

Here is what happened:

1. Added seafoam, primed the bulb, engine started right up, ran for 10 minutes out of gear no hiccups, etc.
2. Took the carb cover off, used a little carb cleaner while it ran for a bit, another 8 minutes with no problems.
3. Since it seemed to be running fine, I put it in gear and put it under a light load for 15 minutes, and it ran perfectly....
4. Did the hand check for overheating- no problem putting my hand on the head and keeping it there.

Thoughts? If I have a fuel pump issue, or a bad cylinder, wouldn't it have shown while it ran for so long this morning? Especially under a load...

 

[V153]

Might still have a weak pump. Won't know til you wind her up a lil.

 

[Fed]

Thoughts?
Primer valve not shutting off the fuel properly.
Next time it plays up try pulling & plugging the input hose and go fishing.

 

[SparkieBoat]

may be something as simple as fuel hose/connection getting pulled the wrong way and sucking air. I always bypass the connector at the motor and do a straight barbbed connector at the tank. those clip on hose connectors suck.. literally.

 

[Party hut Chris]

Ok- so got it out on the water yesterday with a friend- motor would begin to bog down, and then run fine if he pumped the primer bulb. THEN, alarm starts to go off after about 10 seconds...new wrinkle.

 

[jakedaawg]

OK. You have questionable compression. That needs to be addressed 1st. Try OMC or BRP engine tune as per directions on can. Might just be stuck rings. Then retest compression. No point in going much further with a bad hole, it will only get worse.

Is the VRO still hooked up? If so I would suggest doing all further Diagnosis while running on a shop tank with 50:1 pre-mix in it.

Was the alarm horn a solid tone? If so an overheat could be due to lack of oil or a lean condition which would explain away a lot of your symptoms except for the fuel restriction. Although an overheat is usually a water supply/stat issue.

With all that said I believe you need to stop, take a breath and attack this in an orderly way with a thought out plan.

 

[SparkieBoat]

if pumping the bulb helped then your fuel pump is most likely bad. but like Jake said above you need to get your compression readings into acceptable range first. what was the compression?

 

[racerone]

Party man---You need to accept the fact that these motors have a common problem with broken piston rings.---Yes your motor may look very nice but could be junk inside.----Find out by removing the bypass cover and inspecting that piston and rings.---All the adjusting / fiddling does not help if motor is in bad shape !!!

 

[Party hut Chris]

Got the boat turned around so that engine is accessible- going to try to inspect pistons/rings this afternoon if the weather holds. Besides obvious damage, what should I be looking for?

 

[SparkieBoat]

broken piston rings and or scarring on the piston skirt