Fuel and Air Injectors

[tomloans]

I just took out my Air Injectors and ran Carb Cleaner through them and replaced the o-rings and sleeves. I then took off all six fuel injectors and noticed that 3 of the small fat o-rings had deteriorated. I cleaned them also and replace all o-rings.

No more coughing in the morning at first start-up nor do I have need to pump the gas before starting. It starts right up in the mornings. Plus the motor is day and night more power and hops out of the hole now. Who knows how long this has been going on. I only have had this motor (2009 250 pro xs) for 2 years and it has always seemed sluggish out of the hole but I didn't know there was a problem since I wasn't familiar with Mercs. (25 years Evinrude) I thought this sluggishness was normal. Now it is powerful out of the hole and very responsive in all RPMS. I am very happy with the results.

If you have 400 + hours on your motor, I would strongly suggest you send in your fuel rails and injectors and get everything cleaned with all new o-rings and sleeves. You'll thank me later.

[ChrisCarsonMarine]

I just took out my Air Injectors and ran Carb Cleaner through them and replaced the o-rings and sleeves. I then took off all six fuel injectors and noticed that 3 of the small fat o-rings had deteriorated. I cleaned them also and replace all o-rings.

No more coughing in the morning at first start-up nor do I have need to pump the gas before starting. It starts right up in the mornings. Plus the motor is day and night more power and hops out of the hole now. Who knows how long this has been going on. I only have had this motor (2009 250 pro xs) for 2 years and it has always seemed sluggish out of the hole but I didn't know there was a problem since I wasn't familiar with Mercs. (25 years Evinrude) I thought this sluggishness was normal. Now it is powerful out of the hole and very responsive in all RPMS. I am very happy with the results.

If you have 400 + hours on your motor, I would strongly suggest you send in your fuel rails and injectors and get everything cleaned with all new o-rings and sleeves. You'll thank me later.

Tom,you may have saved your motor,but you may not have as well,and actually may have increased your risk of damage.We rebuild lots of optimax motors and find often detonation damaged pistons are very often associated with injectors that are just a few percent lean.An even leaner injector results in poor performance,but the lean cylinder may well not make enough power to hurt itself.By partially cleaning the injectors you may increase your detonation risk...Moreover,different models of motors have cylinders that are inherently hotter running than others,and it is beneficial to place the higher flowing injectors on those cylinders.True testing cannot be done without a proper flowbench,and if in tolerance the injectors are marked and numbered for cylinder placement.This is our standard procedure,after ultrasonic cleaning and flow testing,and will insure the motor performs properly,and with a greater level of reliabilty,Chris

[tomloans]

Thank you Chris. Good talking to you and good advice! Folks proceed with caution. I would call Chris and he will tell you why. Send it off for cleaning.

[EuropeanAM]

A couple other observations- the o-rings that "Tom" referenced would cause a RICH condition. They were likely deteriorated due to improper operation of the Direct/Air injectors.

Traditional (commercially available) flow benches are virtually useless- even the ones that "claim" to be able to handle "Marine" Injectors (let alone the actual real-world cycle of a TWO STROKE injector).

This is definitely something best left to a professional (someone with thousands (or tens of thousands) of injectors experience).

[ChrisCarsonMarine]

I do agree,there is a learning curve involving the injector service,and the standard automotive machines are not acceptable.After investing quite a bit in and time and equipment,with great success,we are offering this service to outside customers,Chris