71' 50 hp I'm stumped

[TruckDrivingFool]

I don't know what I should be looking at next to solve my no run problem.

All new:
Coils, plugs, power pack, fuel pump and hoses. Carbs rebuilt end of last year.

Motor ran ok across lake to the beach, swam for an hour or so. Motor started hard and acted like it was flooded. Ran for about 10 min through no wake and 5mph so was just above idle. Motor died out. Checked everything and thought it was possibly from old fuel (running on last years tank). I switched to a tank I just filled yesterday and got motor started again. Though it acted like it had been flooded again. Chocked it up to old gas and ran around for hour or so no problems. 50' from the boat ramp as I idled it down it died again. Now it won't start at all. I have fuel to the motor at the pump. Fuel oozed out of the nipple leading to the lower carb and I have spark.

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

Almost forgot when I pulled the plugs out just now they appear to be dry. And the fuel pump was replaced as an entire unit not just a rebuild kit.

 

[bonzoscott]

Re: 71' 50 hp I'm stumped

If the plugs appeared to be dry and the fuel pump is new, the filter/screen in the fuel pump is clogged. All of the maintenance you did to it: sounds like the tank (or fuel system) wasn't clean. Of course, could be something else...

 

[Daviet]

Re: 71' 50 hp I'm stumped

Try squirting some fuel mixture into the carbs, if it fires off I would look at the fuel delivery system, lines, pump, carbs.

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

Thanks for the replies,
Ya I checked the screen and it's clear.
When spraying the fuel in, I'll assume that I need to hold the butterflies open. Correct?

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

Well today I went out and got already to squirt fuel in it and see if it would start. Got the muffs on and water running, did nothing more than bump the key (no spray yet) and bam she fired right off. Ran, started, stopped, repeated. Runs like a charm on the muffs.

So I took to the lake and left it strapped to the trailer and ran, stopped, started, repeated. Ran like a charm. So I decided to take her out and it ran great. I did everything I could think of idled, half throttle, WOT. Floated in neutral, stopped went swimming (was trying to think of things that we did yesterday to try and recreate situation) no matter what the motor ran perfect. I mean the best I have ever had it run type perfect. No hard start, no stumble, nothing.

So now I'm wondering since I completely drained the fuel line when I switched tanks to get rid of a much old gas as possible if perhaps the primer bulb had some trapped air in it then when I came down to idle worked it's way into the system. When that happened could it of air locked the line? I know anything is possible but how likely is that?

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

There that's better fixed all that carpy phone posting, any thoughts on the line developing an air lock that was bled out when I took the filter cover off?

 

[tx1961whaler]

Re: 71' 50 hp I'm stumped

Pretty well the only way it could "air lock" is if the fuel tank vent was closed or blocked, or the primer bulb was defective or backwards.
The float needle valve in the carb could also be sticking closed.

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

I'd thought about the needle sticking but since it didn't even try to fire and both cylinders were dry I'd kinda ruled that out. A defective primer bulb though, maybe I'll throw and extra in the boat just in case.

Thanks for your thoughts whaler.

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

Ok here's where I'm at - observations and questions are at the bottom

Since it ran so great when I was trying to get it to mess up I took it out Sunday. fired right up at the boat ramp and ran great across the lake. After spending some time at the beach it finally did it again (when I didn't want it too of course) when I pulled the filter cap off the pump barely any fuel came out. However this time I had help from a fellow boater and when he squeezed the bulb I got a great squirt out of the cover.
When I pulled the plugs to check for spark they were both wet, and of course I had spark.

We finally got it to start by having me stand there cranking the motor and fellow boater was pumping the bulb. Once restarted it ran great the rest of the day and started with just a bump of the key.

So I'm coming to the conclusion that somehow I'm losing my prime charge when it sits.

Two things I noticed I have a hokey band style clamp on the fuel hose from the pump to the upper carb. It had allowed the hose to slide down on the nipple. It's tight enough to prevent leaking but not tight enough to hold the hose from slipping. I got the hose pushed back into place but I will be replacing that clamp.
The second is that at the end of the day when I tipped the motor up into trailer position fuel ran out of the motor side connector for the fuel hose.

1. I always though the connector in the cowling had some sort of oneway valve to it, is it just a pass through type of fitting? Does this show that either there's something wrong with this piece or just a clue that I've got some kind of air leak in system on the motor side?

2. While my tank hose/bulb assembly is a new I got it from Walmart (can't remember the maker) and I've read about troubles with the non-OEM that usually follow with the recommendation of an actual OMC assembly. Does this still hold true and is there a better place to get an actual OMC than just from the Evinrude parts store?

Any other opinions/thoughts are welcome.

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

Too descriptive?

How about - Is the Evinrude/BRP site the only place to find a guaranteed OEM primer bulb?

 

[boobie]

Re: 71' 50 hp I'm stumped

Try any BRP Dealer.

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

Thanks boobie

 

[F_R]

Re: 71' 50 hp I'm stumped

Stop guessing. Next time it won't start, remove one of the drain plugs from a carburetor. Does gas run out? Then it is getting gas, so it isn't the hose and all that other stuff you mention.

But did water run out? That would be a no-brainer---water in the tank.

No gas run out? Is it a built-in tank? Antisiphon valve???

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

Thanks for the smack FR, I had to look at the parts diag to remind myself where the drain plugs were as I didn't remember seeing them.:facepalm: I will check that.

And using portables not a built-in.

 

[TruckDrivingFool]

Re: 71' 50 hp I'm stumped

Well I went ahead and replaced the hokey clamp that was letting the hose from the pump to the top carb (main feed) slide around. I also replaced another that was the same style on the inlet line to the pump. I also switched out the primer bulb.

Took the boat out yesterday afternoon and it started with just a bump of the key and ran great all day!

Hopefully I have this whipped but if not I'll be back after checking for fuel in the bowls as FR said.