1986 Evinrude 225hp Diagnostics Part 4 - final??

Scene 1 - during the replacement of some 3/16" ID hose I found that the fuel manifold had a crack at the base of the nipple that fed the bottom starboard side carb...the lean pop from parts 1,2,3.

Replaced the manifold and some hoses and found the lean pop to bottom starboard carb was gone, but a less frequent lean pop had gone to middle port side carb, (the carb that had sooty deposits some times from previous videos)

Spoke to the Marine Doctor on his forum and he confirmed that if your carburetors have a raised edge where the float seat screws into the carb bowl, then you do NOT use the nylon washers.

Scene 2- Removed the nylon washers from under all float seats, readjusted the floats. Replaced a kinked 3/8" ID fuel line from the VRO to fuel filter cup with a 90 degree elbow with 3/8" ID.

Also found one of the tanks' vent hoses had water trapped in it...blew that out and reattached it fuel tank. The vent hose must be forming a p-trap somewhere, making it difficult for the VRO fuel pump to suck gas.

It appears the lean pop is gone and the motor is idling pretty good.

Starting the motor has become easier too. It doesn't turn over on the first turn of the key like newer motors, but holding the primer key switch for several seconds before cranking, then cranking for a few seconds and one good rev up on the throttle was enough to keep her running, where as before I would have had to do this ritual several times.

Category:

Autos & Vehicles

Tags:

• cfauvel
• 1986
• 225
• hp
• evinrude
• bombardier
• omc
• johnson
• outboard
• diagnostics

[saltwaterallday]

what type of boat is this on?

[cfauvel]

@saltwaterallday It is on a 21' center console, whose brand name is Offshore. I really poorly made boat, but the lines are awesome....replaced everything in 1993, floors, stringers, transom. Still solid after all of these years. It is paid for , so no need to sell it.

[cfauvel]

The idle speed should be around 650 +- 50 rpm in forward gear in the water.

Adjusting the idle speed this way has made a world of difference, the engine is running richer (may adjust idle air bleeds) and cold starts in 2-3 cranks.

It has never cold started this well in the 19 years I've owned it....

[cfauvel]

OK for these engines there are two screws near the flywheel, one that is on the end of what looks like a cigar (the one that in question) and another that is just a stop. The one that is just a stop is the WOT max advance stop screw, the other is the idle advance screw, which adjusts the speed as well.

Screw it in(clockwise) and the engine retards and slows down, unscrew it (counterclockwise) and the engine advances and speeds up. to be continued...

[cfauvel]

Update to all...will post a #5 video soon, but in the mean time a little update. It appears I have been adjusting the idle speed all wrong, by using the Idle STOP screw...by doing it that way I was cracking the butterflies slightly and effectively bypassing the idle air bleeds and running too lean at idle. Not sure if this is true for all Johnson/evinrudes or not, but is defintely true for 1987/1987 v6 engines.

The proper way to set idle speed is by the timing advance...continued on next post..

[wetbootsmoke]

Sounds good buddy....But remember, these engines are VERY SENSITIVE to back pressure, so the only true test of idle quality is actually running the boat in the water....But, generally speaking, if it isn't lean popping on the hose, it probably won't do it in the water....D

[cfauvel]

@wetbootsmoke Took it out this past weekend...ur right the engine wouldn't idle in the ocean set at the 1000rpm. Had to adjust the rpm out on the water to about 1200, on land that equated to something like 1400+...What a differnece...some threads speak of drilling the Idle Exhaust Relief holes larger to allow the pressure to escape there above the water line...

[saltwaterallday]

video of boat running? it would be cool to see how it is running,fuel numbers,top speed etc, impressive work. i want to go look at a old bonito 26 with 2 of these engines on a gill bracket. i dont think the engines run so it will be interesting.

[valdi9165]

@cfauvel Get yourself one of those big plastic storage bins I think some walmarts sell them. If the fins are in the way unbolt them for clearance and reinstall when done. Make sure you have no air leaks, restrictions and the synchronization must be checked this is the ignition timing in relation to all the carb plates . The carb plates must all be closed at idle. Again check your timing with the motor loaded. Hope you got it fixed.

[cfauvel]

@valdi9165 any idea where I could get one.. I need one that is over 30 inches long and slightly over 24" wide since I have those dolefins bolted onto the cavitation plate.

[valdi9165]

If you were to use a 50 Gallon test tank and start it up the cough/sputtering would be so much more pronounced as you would have some exhaust back-pressure and you could clearly see the cough through the exhaust ports and which side its coming from. I think some mild cough is normal in these big v6 and up motors.