Need help de guming engine

[Big T Bassman]

Looking at a 1996 Merc 150 EFI that has been sitting 2 years not winterized. The owner said he was told by a mechanic that the fuel system was gummed up, fuel pump etc. What would it take to get this cleaned up and back to working order. I have worked on cars all my life so I'm not afraid to delve into an outboard. Any info would be greatly appreciated. Thanks T

 

[WillyBWright]

Re: Need help de guming engine

Boy did you come to the right place! Welcome to iboats.<br /><br />The injection system is fairly well enclosed and not exposed to the air. The gas in a good deal of the system should still be alright. The vapor separator tank would be one place where oxygen is exposed to the system and varnishing should be confined there. That's where the high pressure electic fuel pump is. Here's where I can save you a bunch of money...<br /><br />The vapor separator will have to be taken apart and cleaned. Not much in there. Far from Brain Surgery! The fuel pump can probably be saved. I rigged a DPDT momentary switch so that when the lever is pressed one way, the polarity to the pump is normal. Press the lever the other way and the polarity is switched. By rocking the lever back and forth, the armature in the pump goes back and forth a tiny bit until it suddenly frees up. I have saved several pumps this way. A little carb cleaner in the intake and output side helps too.<br /><br />Good luck and if you need me to expand on how to wire the switch, let me know.

 

[Big T Bassman]

Re: Need help de guming engine

Thank you very much for your expert advise. What a great site. Now that I know that it can be done without a lot of expense we start working on the price of the boat. T

 

[rodbolt]

Re: Need help de guming engine

hello<br /> whike that method works most times( I use combustion chamber cleaner and just let it soak first if its stuck) those pumps are rather expensive. I think the 95 150 had an externally mounted pump. but the vapor seperator will still need to be cleaned. and rebuild the low pressure fuel pump. install a new water pump maybe t-stats and a pressure relief diaphram and go play.<br /> good luck and keep posting

 

[Big T Bassman]

Re: Need help de guming engine

Thanks, We have agreed on a price for the boat with the condition that the compression comes out good. What should I expect to get cold on the 150. Is there anything else I should check before I write the check? Hopefully the gummed up fuel in the only problem. T