Fuel Problems

[BigNiner19]

1989 V6 Excel 225

Motor seemed to be firing up just fine and running on the hose. Finally put the boat in the water and idled away from the dock for about 10 minutes and the motor quit. Now on the water I could not get any fuel to pump through the bulb, essentially sucking air it felt like.

I came home now suddenly I am able to get the bulb to pump up nice and hard again and even see fuel running to the filter on the motor, but every time I try and start the bulb goes soft and it wont fire up.

Fuel pump? I cleaned the carbs thoroughly a week ago. Any suggestions.

I can continue to pump the bulb and it will get hard, but every time I try and fire the motor up it goes soft and motor wont run.

Cory

 

[Monte1961]

Re: Fuel Problems

Will it stay running while your sqeezing the bulb?

 

[BigNiner19]

Re: Fuel Problems

Monte,

Can't get it to fire up long enough to get back there and find out. It turns over and fires up for a split second and dies every time. Every time I try to start the motor the bulb was pumped hard, and then went soft.

 

[BigNiner19]

Re: Fuel Problems

Changed the fuel pumps, wasn't the problem. Im sure it was still a good move to replace them, but it didnt fix the issue. I am definitely getting fuel to the carbs, but obviously something is going wrong at that point. I sprayed some carb cleaner directly into the carbs and was able to start it up for a couple seconds.

I guess this goes back to "dirty" carbs ?? I can't think of anything else. I've pretty much trouble shooted everything else. I just cleaned these things!

 

[Silvertip]

Re: Fuel Problems

Primer bulbs DO NOT stay firm once and engine begins cranking and after it starts. Why is this you say?? Well -- it is because fuel is "sucked" through the fuel line, not "forced" through it. Forcing fuel to fill the carbs is why you have a primer bulb. Once full, the engine starts and the fuel pump sucks fuel so there is no pressure except on the output side of the pump. Did you pull the plugs to see if the engine is flooded? If so, the carburetors probably need cleaning and/or rebuilding. It may also be that the engine has lost spark. You didn't accidentally pull the kill switch did you??

 

[BigNiner19]

Re: Fuel Problems

Yea, I get that with the primer bulb. I may have had multiple issues, because I put a new primer bulb on it and it will pump up solid now.

I replaced the two fuel pumps on the motor, did not fix the problem. Kill switch is fine. The motor definitely has spark. When I spray carb cleaner in the carbs and try to start it, it fires up for a couple seconds and dies. So somehow fuel is not getting fired in the carb. I have confirmed that fuel is getting to the carbs though. I would guess, clogged up carbs again? I just cleaned them a week ago.

The issue I may have, is I'm not sure how good of shape the floats and needles are in. They seem to be doing what they should, but I'm not to experienced with the set-up yamaha has on this "nikki" carb.

Cory

 

[BigNiner19]

Re: Fuel Problems

Anyone know about the floats + needles with these carbs? Could that potentially be my issue? They seem to be moving freely working correctly?

Cory

 

[Silvertip]

Re: Fuel Problems

The needle and seat and float just determines how much fuel is allowed INTO the carb float bowl. From there air passing through the throat of the carb must draw fuel through the various tiny passages and jets. If they are plugged up the engine can't run. While you may be sure fuel is getting TO the carb, your can't be sure it is getting INTO the carb, or THROUGH the carb. It appears you have a bunch of trash getting through the fuel system and it is being stopped at the carb. You do have a fuel filter on this engine I hope.

 

[BigNiner19]

Re: Fuel Problems

The needle and seat and float just determines how much fuel is allowed INTO the carb float bowl. From there air passing through the throat of the carb must draw fuel through the various tiny passages and jets. If they are plugged up the engine can't run. While you may be sure fuel is getting TO the carb, your can't be sure it is getting INTO the carb, or THROUGH the carb. It appears you have a bunch of trash getting through the fuel system and it is being stopped at the carb. You do have a fuel filter on this engine I hope.

Yea, I know the boats tank has trash in it, thats why Im running off a seperate clean fresh portable tank now just to get the motor running right. Then I will address the boats tank.

And yes you are right, I cannot confirm that gas is getting through the carb, but I know its getting in there. I have a filter on the motor, an in-line filter in the line and a water seperator as well.

Cory

 

[BigNiner19]

Re: Fuel Problems

Any other ideas guys? The motor was idling pretty good down the river on Thursday and quit, and ever since I have not really been able to get it to fire up (without starter fluid)

I know I have spark and compression, and fuel getting into the carbs.

 

[Monte1961]

Re: Fuel Problems

I would have to agree with earlier statements regarding carb issues. If there was and trash left in the hoses Pryor to overhauling the carbs and hopefully you blew compressed air through all air/fuel passages, low and high idle! To some this all up, sounds like a redo on the fuel system! Please post back what you find!

 

[BigNiner19]

Re: Fuel Problems

Got it running great! The problem originally was multiple things, and it just took some time and effort to weed through some of the issues. I bought the boat + motor combo from someone who didnt use it much, so it did a lot of sitting.

Thanks to everyone who helped trouble shoot and offer up ideas. This thing drove me for a loop, but finally got my finger around it. I still have plenty of work to do, but atleast some questions are now answered!

Here's a breif synopsis of what happened, in no particular order.

- Didnt have good spark - Had 3 bad resistor caps - replaced and had good spark again
- Would not start, but had good spark, was not getting fuel
- Cleaned carbs, fired right up, ran crappy and then would not start again
- Went through fuel hoses, replaced some, did some tests, started and ran crappy again, then would not start at all
- Cleaned carbs again (yes they were dirty again that quickly) and determined my boats fuel tank is contaminated.
- Hooked up portable fuel tank, motor was screaming and running real good, then died (FYI if you use a portable fuel tank, make sure the little plastic vent is open!!)

So to this point, I'm pretty sure the motor itself is back in good running condition, I know that I need to replace a fuel tank for the boat.

Now if I can figure out whats wrong with the tilt + trim, I could actually use the boat some!

Cory