1997 Evinrude 175 BE175EXEUC with fuel starvation issues

[mgrossman_45]

Greetings,

I have been having fuel starvation issues for some time now. It happens above 3000 rpm. I previously rebuilt the VRO fuel pump with Autu Parts 435921 for Johnson Evinrude VRO Fuel Pump HP 435921 436095 Rebuild Repair Kit. did not help. I then decided to disable the VRO oil portion of the system and pre-mixed gas 50:1 now. in a 5 gallon portable gallon tank to eliminate fuel tank issues. Still no help. I then removed the VRO fuel pump. Installed after market Mastertech Fuel pump MTM-06/150 www.maxrules.com. I have removed all carbs and re-adjusted floats. I have replaced all hoses to avoid vacuum leaks. I just do not understand how the Vapor Tank works and if the issue could be there.

I also intalled a temporary automobile 12 volt low pressure fuel pump in line between tank and fuel intake. I have it wired so I can turn it on and off. If I turn it on and force fuel into the system, my problems go away but that is not the solution I want.. I have read the manual (tried to by the real OEM shop manual for specific model and year, but cannot find them) working with the SELOC repair manual that covers so many years and engines does not really help. It suggested installing clear plastic tubing and a fuel pump pressure gauge and also a vaccuum gauage but just cannot get those to show any proper results.

Cannot find a good outboard mechanic in my area to help. Any ideas??

 

[racerone]

Checked carburetor float bowls ?----They are known to warp.-----Replace gasket on vapor separator.

 

[mgrossman_45]

Checked carburetor float bowls ?----They are known to warp.-----Replace gasket on vapor separator.

Thanks for that. I did read about the warping of float bowls but wouldn't i see gas leaking from them? Or might they be sucking in some air? How can I test them?
I will order gasket on vapor separator..

 

[ct1762@gmail.com]

the fuel bowls are pretty easy to tell if they are warped just by eyeballing them. the vapor separator works very much like a big carburetor in that it has a float and valve. check those, and the little pump that powers it. diaphragm could be torn or stiff so it wont pump. you can get any manual off ebay from 1993 to 2004. they all had the same basic components. just saw one for $15 (factory... not Seloc junk)

 

[mgrossman_45]

Are you talking about 0335236 Seal, Vapor Separator to bracket?

Thanks for that. I did read about the warping of float bowls but wouldn't i see gas leaking from them? Or might they be sucking in some air? How can I test them?
I will order gasket on vapor separator..

 

[racerone]

No you would not see fuel leakage from the bowl !-----The fuel in the float bowl needs atmospheric pressure in order for the carburetor to work.----If there is a path that pulls air from the float bowl the carburetor may not function as designed !