About a month ago I was having engine trouble.  Turned out to be the number 3 fuel injector wasn't opening.  I had someone clean all the injectors and the engine ran fine after that for about 4 trips.  The other day it started acting up again, low RPMs and rough idle.  After doing some investigating it seems that the number 3 injector isn't working again.  I am now planning on replacing it, so my questions are.

 

1. Can I just replace the 1 bad injector or should I change all 4(motor only has 34 hours). 

2. What are your thoughts on Refurbished injectors?  I can get one for $40, as opposed to $180 from the yamaha dealer.

https://www.amazon.com/Yamaha-Marine-Injector-68V-8A360-00-00-Injection/dp/B00TA4TQMA

3. I see a brand new set of 4 injectors on Amazon for the F114(68v-8a360-00-00) for $70, are these trust worthy? Does anyone have any experience?

 

https://www.amazon.com/Injector-Yamaha-Outboard-Mitsubishi-Eclipse/dp/B016HMHUOS

 

Troy

 

Wow 34 hours on a 9 year old motor?? That motor isn't that much past break in. Honestly I'd pony up and buy the one from Yamaha. It might hurt the wallet a bit, but I think you'd be in a better position in the long run. 

I was surprised as well when the mechanic ran the diagnostic and it showed 34 hours..  The guy obviously never used the boat.  I think that's the main reason for the clogged injector, gas sat in the tank/motor way too long.  I called the mechanic and he told me to bring the boat back in at no charge.  He ran all the injectors thru the Ultrasonic machine again, and reversed flowed all 4 injectors.  He said it was the number 3 injector causing the trouble again.  He said to take it out on a few more trips see what happens. I took it out yesterday and its running great again,  hopefully I'll get lucky, if it acts up again he said we will just have to replace that injector.

Did you drain out all the old fuel and install a new fuel filter?  Seems quite likely to me that the old fuel is/was the problem.

I did that the other day.  I drained the tank, pulled it and rinsed it out with water and even attached a sock to a metal clothes hanger and scrubbed the bottom of the tank the best I could.  Replaced all hoses and filters.  When I first got the boat I drained the tank, but didn't actually look inside it and clean it.  When I removed the fuel gauge float and looked inside the the tank the other day, it did seem kind of dirty in there, so hopefully my good cleaning of the tank will keep the issue from returning.

Having purchased an older boat, I went through the same.  As well as draining and cleaning the tank, replacing all of the filters, I also replaced all of the fuel lines.  There are filter baskets in the injectors and on my 250 yamaha a lot more.