Evinrude 18hp Fastwin Fuel Starvation

[rickycobble]

The 18hp Fastwin is cutting out when I get to around half throttle and on up to WOT. I can go WOT and prime the bulb and its okay for 30 seconds or so and then I guess the bowl is going dry, starting to cut out intermittently, in which I can prime the bulb and its okay again for another 30 sec or so. Carb has been cleaned, float and needle replaced. Float set to level with bowl surface, also set float drop to 1 1/4" per someone in another topic in this forum. Fuel pump is new. Fuel lines and bulb are new. The fuel tank and the fittings on fuel tank and motor ARE NOT new. Gas is 50:1. Any help is greatly appreciated. Below is a video where I'm running it at about half throttle without priming the bulb. You can hear it briefly cutting out while the bowl fills up.

 

[racerone]

Is this motor running on a good original steel tank or an el cheapo plastic tank ?

 

[tomhath]

Sure sounds like the fuel pump isn't doing its job. Check that it's mounted correctly, otherwise it might be defective.

 

[rickycobble]

Is this motor running on a good original steel tank or an el cheapo plastic tank ?

It's an old el cheapo plastic tank. Thank you for asking.

 

[rickycobble]

No Title

Sure sounds like the fuel pump isn't doing its job. Check that it's mounted correctly, otherwise it might be defective.

Anyway to check that it is defective? Would the motor get fuel if the pump was not pumping? Here's a pic of the new fuel pump as its mounted.

 

[lindy46]

Tank vent open?

 

[racerone]

Any markings on that pump indicating ----" UP "--- on it ?-----Try turning that pump 180 degrees.-Steel tank or a plactic " el cheapo " tank ??

 

[rickycobble]

Yes, this is an "El Cheapo" plastic tank that has obviously been sitting outside in the weather for a few years. Vent is open an definitely works. I'll check on the arrow on the pump.

 

[racerone]

Check the pickup tube INSIDE the tank.

 

[HighTrim]

I would simply try another tank to rule that out. Could be vent is clogged (take cap off to test), pick up tube is clogged, etc....

If you swap tanks, and problem persists, there is an issue with your pump. Or the float is sticking, or partial fuel restriction, etc...

 

[rickycobble]

Thanks for the replies. I don't have access to another tank to test it, so I may end up having to buy one. I'll try to confirm the inlet inside the tank is good before I buy a tank. I did blow air into the tank through the lines with a low amount of restriction. However, I did not suck air for fear of sucking in gas :-0

 

[Silvertip]

A clogged vent or pickup tube in the tank would cause the fuel starvation, HOWEVER, that is immediately identifiable by a primer bulb that goes flat -- just as a plastic soda bottle does if you suck hard on it. As you draw fuel out, air must replace it. But if squeezing the primer bulb allows the engine to pick up again, fuel starvation is the issue and needs to be repaired as a lean running engine will eventually damage itself. Drain the tank into another container while straining the contents. Check for pieces of red plastic material. I've seen bits of plastic that were part of the tank manufacturing process left inside the tank and partially clogging the the pickup. I've even checked new tanks at stores and found plastic bits in them. Of course a bad (new) fuel pump, or one that is not getting a good vacuum/pressure pulses is also a possible cause.

 

[rickycobble]

I'm hoping I've found the problem. When I got a new fuel pump, I googled the part # and found an ebay link for one. I thought it was the one I had searched, but after checking, the one I bought was not the correct one. It was rated for motors up to 15 hp. I just got the correct one in the mail today. Hope this is the fix.