Yamaha 90hp becoming hard to start

[shaunjones]

Hi all,

I recently purchased a boat with a 1989 yamaha 90hp on it. Initially it had a faulty low oil sender unit and the engine alarm would go off and limit my revs. I had that fixed and it ran fine for a while. I noticed over a month or two the engine is getting harder and harder to start when cold. When it is running its fine, kicks over really quickly.

It has dual batteries so power is not the problem, but it isn't sparking for a long time. I tried to start it today at home and turned it over for about 1 minute and it didn't fire at all. I tried for a few minutes and gave up.

I did notice a few times that the motor would sometimes make a struggle sound when running at low speeds. And when I went to take off, it would cough and splutter then it would take off and eventually get to top speed. But most times it would run normal and be really responsive.

The main problem is the engine not wanting to spark or fire. I'm not sure what it is, I always prime it right up, but it has been getting worse and worse. When I first bought it, it would fire after 1 or 2 seconds!

Any help would be GREAT!!!

 

[robert graham]

Re: Yamaha 90hp becoming hard to start

I'd start by checking/cleaning/replacing the spark plugs, then drain each carb to check for water/debris in float chambers. Are you pumping your primer bulb until hard, and using your choke? It may need carbs to be removed,disassembled and cleaned. Install a Walmart/Attwood fuel/water separator($28), easy 2 screw install on transom...save lots of carb/dirty fuel problems. Good Luck and let us know what you find!