1998 evinrude ocean pro "idle cough"

[JohnnyFire]

Was on lake winni in nh this weekend and noticed the cough had gotten bad enough to stall the engine. So heres what has been done.

Comp check only 5 psi less than factory and within3 psi on all 6 cyl.

Checked and performed link n sync.
Found cyl #4 to be cause of cough by pulling wires so i swapped coils with cyl #2 to my amazment issue was still on #4.
If i removed the coil for #4 from circuit engine would idle just fine.
Another thing i noticed when i was pulling the wires off the plugs is it seems the spark isnt as strong or prominant as the other cylinders.

Could this simply be a manual timing adj?(i dont think so)

Good news is i have 2 other brains to try cause thats where im at now 1 is used the other is new in box.

Other info...
All carbs have jets 67d crystal clean. New vro. I installed an additional 2 pressure sensors 1 IN FUEL the other in OIL line at pump.(at begining of last season)
I will be back in at the lake sun morning and can rec 1080hd video of the cough and spark issue i am talking about. Please some one gimme somthing to go on before i drive it again and end up calling seatow....

 

[Chris1956]

Re: 1998 evinrude ocean pro "idle cough"

Normally a cough would be a lean idle mixture setting. Try to richen it up a bit. There is an initial setting for the carbs idle mixture screws. I do not have it with me, but is is multiple turns open, from lightly seated. Did you use this spec? Check grounds on coil with weak spark.

 

[daselbee]

Re: 1998 evinrude ocean pro "idle cough"

Don't even know if it is a six or a four. Post model number.

 

[JohnnyFire]

Re: 1998 evinrude ocean pro "idle cough"

Sorry forgot to write down mn but it is a six cylinder 1998 200 hp ocean pro. As far as mix that doesnt seem to be the case due to it idles in neutral and in fwd-rev. As far as spark its no so much weak as its intermittent . As not firing on time or missing completely. Coils have been checked and swapped only to find the issue on the same #4 cylinder. Is there anything else i can test/check before i pull the brain and swap that?

 

[daselbee]

Re: 1998 evinrude ocean pro "idle cough"

I would start with the condition known as a lean sneeze.
Idling fine, the ppoommphhh, and it stalls or maybe catches back and keeps running.
Is that what it is doing?

If so, there are very very tiny fuel passages in the throttle body, they are fed by fuel sucked up from the carb bowl and mixed with air
that comes from that single air bleed you see in the front face of each carb. Should be a #27 or close.

The fuel mix is fine tuned by the idle adj screws down the hole right next to the air bleeds in the front of the carb.

The easiest and cheapest thing I would do first is get a can of spray carb cleaner with a straw. Put that straw in the opening of the idle air bleed while engine is running and spray liberal sprays of it into the idle circuit. Do it for all six carbs.
You may get lucky and dissolve the blockage in the idle circuit that way.

Next I would look at the butterflies being ABSOLUTELY CLOSED at idle.
Check #5 and #6 by pushing on the butterfly with a long screwdriver while running to force the butterfly closed if it is slightly open.
Use care, don't damage anything, just press on it to close it...
See if your lean sneeze goes away. If #5 or #6 is ever so slightly open at idle, you will get crappy idle and lean sneezing.
I say #5 and #6 in particular because they are two that are adjustable....and ppl just don't take the time to make them perfect.
You can check all of them this way tho.

If it doesn't work, you will have to disassemble the carbs and clean thoroughly the idle passages. This includes the throttle bodies located behind the black carb bodies.

There is a plate held on with 4 screws to the side of the throttle bodies. Behind there are incredibly small holes that feed into the throttle bore. Those holes are the ones that you may get lucky with the spray.

You will absolutely have to re-link and sync it, paying special attention to #5 and #6 being absolutely closed at idle.

All of this should be done while in the water, or in a tank. No muffs.

If you still think it is ignition, look into a timing light while running check each cylinder for even firing. You will be able to see irregularities that way.

 

[JohnnyFire]

Re: 1998 evinrude ocean pro "idle cough"

Thanks for the info das i will give it a shot tomorrow when i yet back up to nh where the boat is but for spare parts/reference ill bring the complete intake off my spare blown powerhead.along with omc manual and clymers.

 

[daselbee]

Re: 1998 evinrude ocean pro "idle cough"

Keep us posted. I am particularly interested in the actual fix you achieve.

 

[JohnnyFire]

Re: 1998 evinrude ocean pro "idle cough"

Alright heres the low down.
I listen to dasel and he was right. On the side of the carb there are two plates with philips head screws i removed both plates to find a yellow mess cloging the 3 small i mean small pin holes in the intake manifold. Once i cleaned the blockage and then went to radio shack for a canof compressed air and then to autozone for a can of gumout carb cleaner and a can of spay seafoam i cleaned all the rest of the carbs just by removing the drain screw at the bottom of each carb forcing the sprays in every orfice i could see in the manuals.
Now my engine is smooth and hits 5600
Instead of 5100 with a loaded boat.( 5 people plus me and 55gal of fuel.
I think it maybe time for a more aggressive prop.
Lol thank you DAS!!!!!!

 

[daselbee]

Re: 1998 evinrude ocean pro "idle cough"

Good to see you running again.

BUT.....all this did was buy you some time til the end of the season. If you picked up 500 rpm....well, I think there may have been some blockage in the HS fuel circuit too.
If it were me, I would overhaul those carbs this winter, pay extra careful attention to the link and sync, and then you will be sure you are good to go next spring.

Interesting to note.....you were pulling plug wires and trying to diagnose it by change in engine sound....
That is not real effective on the V6s, I think. The whole running dynamic of the engine changes when a plug wire is pulled, speed changes, load on crank changes, just all kinds of differences occur....and will mask the true problem.
Just like your case, the engine quit lean sneezing...maybe it was because the lean sneeze was coming from the cyl that you pulled the plug wire from....who knows.

Also, how did you get to the port side carb side plates without taking off the carb bodies? Hard to do....just sayin'.
There is room, but it is tough to do.

Glad you are running.

 

[JohnnyFire]

Re: 1998 evinrude ocean pro "idle cough"

I ground down a philips tip from my srew gun then used a cheapy autozone 1/4 ratchet wrench to achieve the 90deg angle needed. Kit was ordered. But still gonna hit the blue fish tourney in gloucester this sunday.

 

[JohnnyFire]

Das where are need your help again. The sneeze is back. Ugh! Gonna overhaul the carbs. But noticed after chaning the plugs two of cylinders are definitely lean one seems to be rich and the others are fine. Also changing the pulpit valve and t stats as it has been running a little to hot on 1 side. Also adding 2 new external temp sensors and gauges to keep an eye on each side. If there is anyone on here that is will to come to saugus mass to give me a hand I'll buy the beer wife will cook on the steaks need to get this ready for the 4th of July. Hope to attend the fireworks in Gloucester ma.
Engine info E200CXECM G 04425301 ENGINE FAMILY W1PXM0183210