My first Yamaha 1.8 issue in 8 years.

[Evil Sports]

Got out today for the first time this season and since changing my impellers and housings. Excited to feel that 7k pull and notice my starboard engine is not keeping up. Ran around hoping it would fix it self but no. Didnt really have the tools necessary to dig too deep but heres what I figured out. After pulling coils 1 by 1 each time I removed one that engine would run terrible so I would put it back and move on to the next. Finally got to the last one and it didnt affect the running so I narrowed it down to the last cylinder. When I got back and pulled the cleanout plugs I could smell fuel so Im ruling out injectors for now. Now that I think about it, I havnt changed the plugs in 2 seasons. Has anyone had spark plug or coil failures on 1.8s??

 

[Cobra Jet Steering LLC]

Better do the plugs and use dielectric grease on the coil boots to keep moisture out and the boots from sticking to the top of the plugs.

 

[Ronnie]

I had a plug and coil fail at the same time, it may have arced and eventually caused the valve cover seal to leak.

 

[Evil Sports]

Ronnie, how did you got all those lose parts outta the hole

 

[Quad]

@Ronnie I lived in the north end of Fremont practically in Union City for years!

 

[rkluck]

I would change the plugs every year. I found when they started to go the engines would stall when idling especially after she had been running for awhile. It was an easy thing to do and that was part of my annual maintenance.

 

[Ronnie]

Ronnie, how did you got all those lose parts outta the hole

All that stuff came from the coil side of the spark plug. I had to use tweezers and a shop vac as well as remove the valve cover to clear it all before I removed the spark plug. I didn’t get anything out of the cylinder it self.

I used to replace my iridiums every two years, now I just use standard plugs and may start doing so every year again.

 

[Evil Sports]

I hope to get the coil off Wednesday or Thursday and see what Im working with. Do you have the style number for standard plugs