Any outboard gurus out there?

jamisonace
jamisonace
This has to be a simple fix.....please make it a simple fix, I'm tired of taking motors to the shop.

Early 2000's Yamaha 9.9 4 stroke

Had it running perfectly down in the valley. Purred at low RPMs and ran all day long on a slow troll. No issues. Then I took it to Odell and of course it ran like crap, could barely get it to idle until I had the brilliant idea to mess with the air mixture screw and further adjust with the idle screw. Of course I had no idea what I was doing but I got the boat to run well for about a day and a half before I fouled the plugs so bad it was barely burning fuel and instead burning my eyes with black exhaust.

I figured it would be as easy changing the plugs and re-adjusting the screws but clearly that's not the case. It does run much better than on the mountain but here is the issue I'm left with.

***Idle runs high and won't run if I adjust the idle to a reasonable rpm.
***When I get the idle as low as I can (still not as low as I want) it runs for a minute then the idle slows and it dies
***When I have the idle set high, it dies when I switch into gear. I can make it go into gear and run but I have to put throttle to it and I'm sure this isn't good for the motor. Furthermore, the idle is so high that my troll would probably be around 3 or 4 MPH

Any ideas out there would be much appreciated.
 
Last edited by a moderator:
P
Pni_fisherdude
Sounds like your mixture is too lean. Try to get your mixture more rich and that should bring your idle down as well.

When you put it in gear, it sounds to me like there is not enough fuel for the added load on the engine.
 
jamisonace
jamisonace
Thanks for the input @Pni_fisherdude. I've been adding air and reducing fuel. Definitely moving in the right direction. I have the idle down a bit but not where I want it. However, I am able to get it in both forward and reverse without killing it. I'll keep messing with it today. I think I'm getting there. Pretty sure someone competent would have had it done in minutes.
 
S
Snopro
Have you cleaned the carb and jets?
 
jamisonace
jamisonace
Snopro said:
Have you cleaned the carb and jets?
Yes, before I took it to Odell. About 3 months ago.

I know I probably got crud in there so I also put Lucas Oil fuel additive in my tank yesterday before I started working on it. If all else fails I'll have to clean them but it seems to be clearing up. Hope to avoid that.
 
00Swede
00Swede
I'm no "guru" but I've cleaned a few outboard and small engine carbs. I'm a believer in fuel additives but in my opinion when those kind of symptoms start it's too late, but I hope it works for you.
The best advise I've seen on this came from an internet "guru". Tear the carb down as far as you can. Lots of carb cleaner,welding tip cleaners and high pressure air. Put it together. If it still does it then you didn't clean it good enough.
Run non-ethanol fuel with "Sea Foam" additive in every tank, religiously. I run it in all my small engines and outboards.
Good luck.
 
Chromatose
Chromatose
Early 2000`s ? Might just be time for a Carb rebuild kit. Works every time I have problems that the adjustments on the Carb can't fix.
 
jamisonace
jamisonace
Chromatose said:
Early 2000`s ? Might just be time for a Carb rebuild kit. Works every time I have problems that the adjustments on the Carb can't fix.
I would agree but I just had it done and it was running perfectly before I went to high elevation and screwed with it. I've actually had the carb professionally rebuilt twice and cleaned twice since I got it about 8 years ago. That said, it may have gotten some crap in it.

Anyway, I have to take it out and test it on the water tomorrow. I've been tuning it in a garbage can but I'd like to see how it feels pushing the boat and how fast my slowest troll is.
 
D
Diamond Lake Charlie
Not a guru but it would be nice to know what you have. Here are a couple of questions for you. Is the tank portable and if so when is the last time you cleaned, what kind of a filter do you have and have you changed it? where does it set in the winter? How often do you put fresh fuel in it.when is the last time you changed you plugs nd I may have missed but is it two or four stroke. When was the last time you just ran it full bore with a cleaner in it. One thing I will tell you is just puttering along can cause them to foul up, take it out and run it once in a while. I have two engines on my boat and one of them is an 8 hp four and it often sets and gets hard to start and I often just run it to make sure it is ok..It is my come home engine, my 90 gets run on top end a lot and believe it or not I can use it for trolling for salmon and have to speed it up and I can use it for trolling for trout.. One thing I noticed is you said you took it to high lakes, if it is a two stroke and over 5 k in height you may have to change jets.
 
  • Like
Reactions: jamisonace
jamisonace
jamisonace
I screwed with the air fuel mixture long enough that I finally got lucky and adjusted it correctly.
 
  • Like
Reactions: 00Swede and Chromatose

Similar threads

NKlamerus
Replies
118
Views
10K
NKlamerus
NKlamerus
B
Replies
4
Views
1K
Baydog
B
bass
Replies
4
Views
1K
bass
bass
B
2 3
Replies
42
Views
9K
Wilsonriverfisher
Wilsonriverfisher
C
Replies
11
Views
2K
bigboy70
B
Top Bottom