2001 90HP ELPT carbs leaking

[m.sells21]

Looking for some help... 2001 90HP Mercury ELPT 4-stroke was running fine when it went into storage at end of 2021. Came out of storage and had a hard time starting and staying running - appeared to be flooding. Pulled the cowl off and gas was pouring out of the intake.

Brought the boat to the nearest marina and they said the carbs needed an overhaul so they got rebuild kits and got it all put back together. Carbs still leaking and fuel coming out of the intake. Marina states this is due to corrosion on the carbs themselves and that this is a common issue with these motors.

Was able to source a used set of carbs with only 300hrs on them online and had shipped directly to the marina. The pictures I saw of the carbs looked great and the seller said the motor ran great before the bearings went out so nothing caused by the carbs. Marina installs them and says they are doing the same thing as the original set and they believe them to be corroded as well.

I'm not necessarily saying that the marina is wrong and I'm not saying I bought from an honest seller but the fact that two different sets of carbs produce the same problem seems odd. I'm wondering if there's anything else that could be causing the motor to flood and fuel to be coming out of the intake. I'm already in this motor for a lot of money at this point and the marina is saying the best option is to just put a new motor on. Looking for any suggestions, thanks!

 

[Dave1027]

Was the floats and needle valves replaced with brand new ones? It's a simple matter of getting the needle valves (and seats) to close off the fuel once the bowl reaches a certain percentage full. Maybe the carbs are a bad design but one would think an adjustment of the floats should solve this issue.

I'd take a carb off the motor and hook it to a fuel line pressurized by pumping it with the primer bulb. Then drain the carb into a container to measure the amount.

 

[Thirsty Endgrain]

I have the same engine. I just went through the carbs completely, twice.

That particular issue happening twice and the marina telling you to get a new engine (as if we all have a spare 12k laying around) seems suspect at best. My sense in my short ownership of this engine is that there are not many who want to deal with them anymore, and "get a new engine" is an easy fix for them.

Anywho, yeah you're going to have to test each carb individually, as Dave said above.

However, as far as other issues it would be, my only guess is that you have a valve sealing so poorly that compression strokes are pushing fuel back out of the intake. Have you done a leakdown test? I would add that to your list of troubleshooting.

Did you store it with fuel conditioner? These engines are highly notorious for clogging their tiny passages in short order of you don't run conditioners, stabilizers, etc. Not part of your issue probably, but just in case.

 

[ThomW]

It really seems like a stuck float or needle valve in the carbs. Seems like this marina is asking you to just keep pouring money into a problem they aren't sure about. I would thoroughly soak the carbs in cleaner...check the needles to make sure they are not damages...check float adjustments...and rebuild them before I spent any more money on other things.