1999 Evinrude 15 4 stroke running too rich?

[caxton]

Hi-
I just bought a used sailboat with a used 1999 Evinurde 15hp outboard. It starts fine, often with no choke whatsoever. When I give it more gas it often hestiates and sometimes stops altogether. If I play around slowly increasing the throttle, I can eventually get it to go.

What should I check for or adjust?

I also have a tach installed which doesn't work, its new so I think its not connected properly, any advice or knowledge on what connections I should check?

Thanks.

Caxton

 

[iwombat]

Re: 1999 Evinrude 15 4 stroke running too rich?

Does it pop or sneeze at all when it hesitates?

And, is this just when coming off of idle, or through the entire rpm range?

 

[caxton]

Re: 1999 Evinrude 15 4 stroke running too rich?

no, it doesn't cough or sneeze. I have an external bombadier throttle. When I put it in forward to the first position (slow forward), everything seems fine. When I move it to full throttle it is most times sluggish and sometimes kills it. What I have been doing to get it to run at full throttle is slowly play with the throttle by increasing it slowly until it "catches" so to speak and runs up to full throttle. Once it is running at full throttle, everything seems to fine. Of couse until I have to do it again....

Caxton

 

[iwombat]

Re: 1999 Evinrude 15 4 stroke running too rich?

Hmmm . . . Well, I have several theories. Here they all are in no particular order.

1) Dirty carb. Specifically dirty midrange jets.
2) Timing off - too far advanced causing pre-detonation.
3) Ignition - cylinder dropping out. Describe "catches" I'd like to know more about that.


I don't know a lot about this motor in particular, but I do know small 4-strokes very well. Unfortunately, I can't get to the online diagrams right now; the site seems to be down. So, I can't get much more specific until I take a look.

 

[mneng]

Re: 1999 Evinrude 15 4 stroke running too rich?

Bad news and good news. All the 99's are that way. The good news is it can be fixed. I bit of a pain though. The idle pick up tube was bent to make it touch in two places so it wouldn't break from vibration. This restricted the flow too much resulting in a lean mid range just off idle. If you get a hold of a .032" drill bit you can open up the restriction at the bottom and fix it. Trouble is you need to remove and replace an aluminum plug. If you pull the top cover off the carb you will see where the tube is pressed in. Or you can buck up and buy a 2000 or later model year carb, which may or may not have my name on the drawings for the calibration holes. Forgot to mention the idle was set rich to try to cover the problem, but didn't work.

 

[caxton]

Re: 1999 Evinrude 15 4 stroke running too rich?

Thanks for the info. So a 2000 carb should fix it, rough idea on how much that carb is? If you don't mind could you give me a call at 415 595-7266? I would like to hear a little more. or you can email me at mrthodes@comcast.net with your phone and I can call you.

Caxton

 

[mneng]

Re: 1999 Evinrude 15 4 stroke running too rich?

The last I saw a price was in 1999 and it was about what the motor is worth now around $450. I think it was replaced with a branded Suzuki in the early 2000's before OMC went bankrupt, so I'm not sure what parts availability is.