•••Please HELP! FUEL PROBLEM??•••

[Iceman2017]

Please please please help me. Ive got a '00 seadoo challenger with twin 717 / 720 engines. Here's what I've done so far:

-Fixed fuel baffle with F1 fix.
-rebuilt starboard side carb.
-checked fuel selector valve all good.

Rebuilt carb side, IT WONT START! However I can start the port side engine up just fine, so I don't think it's the fuel baffle (btw the F1 fix worked)

I can suck/vacuum fuel from the inlet hose off the carb but when I take the return hose and blow air nothing comes out of the inlet line! (I do hear some bubbles in the gas tank when I first start blowing air into the return) I read here that the inlet line should drip fuel when air is blown into return line. What am I missing!!!??

(Also, I'm not able to get a vacuum on the return line, no pressure will build, not sure if I'm supposed to be able to or not.)

PLEASE HELP!

 

[soccerdad]

So a couple of questions first. Will it try to fire if you prime it with a little fuel in the spark plugs? (trying to make sure it really is a fuel issue). I am not sure about the boats, but I assume it only has one fuel baffle to feed both motors? And then the lines are t'eed somehow?

Anyway, the return line into the baffle just dumps into open air in the top of the tank. The fact that you hear bubbles makes me think you have it connected to the baffle wrong. Are you sure you got the lines right when you did the F1? If you put a short line on the return from the carb spigot, can you suck, vacuum fuel from the carb at that point?

 

[Bills86e]

injecting 3-5 lbs air into the carb return line should result fuel coming out the carb supply line. Don't make the tank swell like a balloon.
Listen for air leak(s) in the fuel routeing system, as like Soccerdad said, lines are incorrect, the fuel selector valve could be clogged, water separator
cup gasket may be bad, and fuel line clamps may not be snug, so the carb fuel pump is sucking air not fuel, this is the problem to solve.
A short line on carb supply nipple and end into a small cup of premix, the engine should run on that if carb is sucking out fuel fine.


Bills86e

 

[Iceman2017]

Yes it will fire with fuel in spark holes. Yes one baffle with T connection to each engine/carb. This is what confuses me, the other engine starts and runs fine. I'm 99% sure I hooked the lines properly to the baffle.

I'll go put a line on the return spigot of carb and test. I'll let you know what I get. Thank you for your help!

 

[Iceman2017]

Thanks Bills86e I'll try that also

 

[Iceman2017]

[MENTION=14691]Bills86e[/MENTION] and [MENTION=69521]soccerdad[/MENTION]

I have main fuel inlet on carb and have a test line from return going into bucket...I get fuel going into the bucket from return..

When I put test line on carb inlet with fuel going in line from a premix cup I get the fuel going into carb, but still wont start....it sucked a whole cup of fuel into the carb but never even sounded like it was about to fire.

 

[Iceman2017]

On a side note: with the air box off...should I be able to see fuel squirting into the throat of the carb when giving choke and or throttle???

 

[soccerdad]

Sounds like you have something wrong inside the carb. Something left out or upside down, stuck? Is it hard to swap on the carb from the other motor?

 

[Iceman2017]

[MENTION=69521]soccerdad[/MENTION]

Sounds like you have something wrong inside the carb. Something left out or upside down, stuck? Is it hard to swap on the carb from the other motor?

I'm afraid to touch the other motor since it's running perfectly. HOWEVER, after taking all of your advice and being able to narrow down my issue...I think I definitely made a mistake with my carb rebuild....I am now realizing that this spring I have under the lever arm of the accelerator pump actually belongs INSIDE the accelerator pump...I am going to fix that this evening and give it a try...I noticed the fuel intake side of the carb will fill with fuel but the other side where the needle/seat is was bone dry. Maybe I wasn't getting enough pressure from the accelerator pump since it's missing it's spring inside under the square diaphragm.

 

[Iceman2017]

[MENTION=69521]soccerdad[/MENTION] and [MENTION=14691]Bills86e[/MENTION]

Thanks, I've got it running now out of water...just for about 30sec. I had the accelerator pump spring misplaced.

ONE LAST QUESTION: is it supposed to idle at 3000 RPM out of water? And I have the air box off of the 2nd engine and that's idling at 1500 out of water... will the air box being off make that big of a difference????

 

[manolocross]

YES they are supposed to idle at 3000. Therefore when you drop in water and jetpump gets loaded(with water), the idle will drop to 1500-1600 rpm. So get the other engine to idle at 3000. What will happen to the engine that idles at 1500? It won't stay running in water. Idle will drop once in water soooo at 1500(out of water)it will stall ( once in water)...

 

[Iceman2017]

[MENTION=38668]manolocross[/MENTION] thanks for the reply! Good to know. So to get my other engine to idle on trailer at 3000 rpm what do I adjust? Also will the air box being off make a -1500 rpm difference in the idle speed? (I just have the air box off temporarily while I'm trying to replace the T and Y connector of the oil lines. The flame arrestor is still on through)

 

[wfo speedracer]

[MENTION=38668]manolocross[/MENTION] thanks for the reply! Good to know. So to get my other engine to idle on trailer at 3000 rpm what do I adjust? Also will the air box being off make a -1500 rpm difference in the idle speed? (I just have the air box off temporarily while I'm trying to replace the T and Y connector of the oil lines. The flame arrestor is still on through)

Airbox being off will not affect the idle speed, to adjust the idle turn the idle screw which is the only one that can press on the tab to open the butterfly, should be fairly obvious.

 

[Iceman2017]

Ok, I believe I know the screw your talking about, thanks.