defuser ring

[keykev]

confused: the ring around my stock prop on my 1988 88hp evinrude is gone. I believe it is called the defuser, i am not sure what its purpose is. the motor starts and runs good but seems to flutter a little between 3800 and 4200 rpm. the prop is a 12.34 by 21. after 4200 it smooths out and tops at 5700. compression is between 125 and 140 and plugs are clean and not fouled. i have been thru the carbs, timing and synchronization. thanks, keykev...............

 

[Raystownboater]

Re: defuser ring

The "diffuser" is basically used to diffuse the exhaust gases around the prop blades during a hole shot for better performance.

 

[Bob_VT]

Re: defuser ring

What is your compression? Between 125 and 140....... I would do a de-carb procedure and see if your compression gets closer to being balanced.

The diffuser ring will have zero effect on performance on the top end of the motor

 

[keykev]

Re: defuser ring

thanks guys, i try the decarb before i put it away for the winter...........

 

[boobie]

Re: defuser ring

I've always used BRP Engine Tuner and had good luck. What ever you use follow the directions on the can to a "T".