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Captain
Posts: 43
Registered: ‎06-09-2015

Re: Exhaust back pressure hose to EMM ?

Admiral
Posts: 8,044
Registered: ‎07-14-2011

Re: Exhaust back pressure hose to EMM ?



@BluewaterBill wrote:

 

 

What does the exhaust pressure sensor tube look like?





@Elto wrote:
5001298 *NIPPLE, Exhaust back pressure

https://www.ebay.com/itm/Evinrude-5001298-NIPPLE-AY-DI-ETEC-/182669097073

 

 

 

What does YOUR exhaust pressure sensor tube look like?



 

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Captain
Posts: 464
Registered: ‎08-20-2017

Re: Exhaust back pressure hose to EMM ?

The way I understand the operation of the system as a tech is that exhaust back pressure is used as one of the inputs to determine engine load. High exhaust pressure equals high load. Under high load the engine will increase oiling. The brass nipple is designed with restrictors to limit/meter exhaust flow through the tube to the sensor.
If your tube was "burned out" it could let too much exhaust through which could melt the hose and cause over oiling.
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Captain
Posts: 43
Registered: ‎06-09-2015

Re: Exhaust back pressure hose to EMM ?

Slightly discolored with no blockage, I did spray cleaner on it just to make sure and reinstalled.

Captain
Posts: 464
Registered: ‎08-20-2017

Re: Exhaust back pressure hose to EMM ?

Since this is the second hose to deterioate the problem has been going on for awhile. Has the excess oil been occurring since new?
My line of thinking is towards the engine running under heavy load conditions, possibly over propped and not able to turn Max rpms
Captain
Posts: 43
Registered: ‎06-09-2015

Re: Exhaust back pressure hose to EMM ?

This is been happening since new I think dealer getting tired of me , boat is propped for 5700 to 6000 rpm.