AR230 - engine/fuel issues

[angi klein]

Hi there! We are having some troubles on only one of the engines. We have a 2005 Yamaha High Output AR230- 160 hp engine. There are no check engine or code lights coming up on the dash.

This is what we've kind of diagnosed. The #1 spark plug keeps fouling (closest to the front of boat). Fuel economy has gotten worse. Plug fouls within 20-30 min of running. Switched plugs and coil packs, seems to run great in the beginning and then after it runs a while then it goes back to the same thing.

When we run the throttles wide open at 9-10k RPMs the engine seems to run just fine. When we are running it around 6-7k RPMs is when it starts acting up and engine can't keep up with the RPMs of the other engine and it just doesn't sound so good.

Do you think it's the ECM? We are unsure and don't want to spend $1000 on a new one and not fix the problem.

But if so, where is the best place to get an ECM new or rebuilt? Could it just be a bad injector?

Any help and advice would be awesome!! Thanks

 

[Bruce]

How does your oil look? I am uncertain if a stuck injector could cause plug fowling but it is a potential issue https://jetboaters.net/threads/engine-issue-oil-in-filter-oil-overfilled.14333

 

[Scott griffith]

I agree sounds like u have a injector stuck probably going to have to get your ecm repaired

 

[scokill]

A picture of the fouled plug would be worth a thousand words. Oil fouled no good, wet gas the guys above are on the right track and seems to be a common (at least for those very few that have the issue) issue.

 

[Cobra Jet Steering LLC]

What color is the plug when it fouls? silver grey is the kiss of death " water in the cylinder" smell the oil if your injector is dirty and leaking it usually puts fuel in the oil and raises the oil level also thus fouling your air cleaner element . I add fuel injector cleaner every 50 hours or so, no issues with those fouling yet.