Fuel Pump Issue - 2004 TLRC 90hp 2 cycle

wholbert

Recruit
Joined
Jul 25, 2016
Messages
2
So this year my carbs were gummed up with this crap we call gasoline with ethanol. So needless to say, my spotless carbs had crapped up needle valves. After replacing both the high speed and low speed needle valves and getting everything running smooth, I decided to take the fuel pump apart to verify that the diaphragm was not hard, nasty and gummed up. There were no tears or issues. I built it back exactly the way it came apart. When I checked it fuel would come out when I prime it, but not when I crank it or run it... Ok, so I think to myself , Self you must have screwed something up or broke a diaphragm, so I order a whole fuel pump kit and go about rebuilding the thing (5 min work). This has the crappy vacuum fuel pump and not a mechanical one (what I would give for a mechanical one). So needless to say, when I crank it no fuel. The fuel filter is really clean and seated, and I have a water separator downstream on the fuel line, new fuel line, new bulb, and when I squeeze the bulb I have great flow thru the fuel pump. All seals and gaskets are in place and built exactly like the diagram on iboats.com. I have broken down and ordered a "NEW" fuel pump online for 25.00. If this does not work not sure what to do....

My engine starts on the first crank and purrs like a kitten when the fuel is in the carbs. There does not seem to be any vacuum leak or anything.

I really dislike the vacuum fuel pump. Yamaha was no help, so I turn to you all and your expertise.

http://www.boats.net/parts/search/Yamaha/Outboard/2004/90TLRC/FUEL 1/parts.html

Any help would be appreciated at this time.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Mine is a 1999 C90 similar to yours....never a problem with the normally trouble-free diaphragm fuel pump....replaced it once in 15 years while the old one was still operating fine...keep it for a spare. A Yamaha fuel pump for my motor was about $50 as I recall....is your $25 pump a Yamaha unit?....
 
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