Fuel accelerator pump issues

[lightbulb140]

I just got done rebuilding carbs and swapping out fuel lines in my 98 spx. I got the ski to idle but when i hit the throttle it bogs right down. I take the two fuel lines coming off the accelerator pump and nothing comes out of them when i press te throttle. If someone could give me a brief explanation on how the accelerator pump works like where the fuel comes from and how it is supposed to operator and tell me what could be wrong and how to diagnose and fix the problem. This project has been going on for 2-3 weeks now and i just want to get out on the water and ride my ski!!!!!

Thanks in advance

 

[Strizzo]

the accelerator pump has a check valve that only lets fuel go towards the carb. there might be a check in the pump inlet itself too, can't remember exactly. but it works just like the pulse pump on the carb, when the carbs first open, there is a lever that pushes on the pump diaphragm. this pushes the fuel out of the pump through the check valve, then when the throttle is released, the check valve closes and the pump diaphragm pulls fuel from the carb supply. the purpose is to supply a small extra amount of fuel as the throttle is opened, which allows the low speed needles to be run a little leaner, which makes the engine less likely to load up at idle and bog down coming out of a long no-wake zone.

 

[lightbulb140]

So what would be a good way to diagnose on why I am not getting fuel through this pump? Cause I’m assuming that it should squirt out fuel every time the throttle is pressed.

 

[summer]

Pull the pump and lines off and see if they are clogged. The pump has a diaphragm that could need replacing. With mine the lines were clear actually but once the piston was depressed is would not return to its normal position. Its pretty simple once you look at it.

 

[Strizzo]

mine had the same symptom as summer's it would go down but wouldn't come back up, turned out to be a clog in the bend at the bottom of the pump where it turns to go out the side to the check valve. i put 100psi compressed air on it, nothing, soaked it in carb cleaner, nothing. in the end i started poking a small allen wrench in the passage and broke loose whatever it was that was plugging it up. even with no fuel in it, you should hear air coming out of the jets when you press the plunger

 

[lightbulb140]

I have taken it apart and cleaned it and seems all good. Im still not getting fuel out of it when i press the throttle. If i suck on the outlet line to pull gas in i can get some to come in then after 2 or 3 presses on the throttle it squirts out and stops after that. So could the check valve on the inlet side be gummed up/ malfunctioning? cause i did try to clean them as best as i could but since they are check valves its a pain in the butt.

 

[Strizzo]

i'd say check "everything". pull the check valve and make sure it stops air one way and not the other, blow air through the pump itself, through the lines, through the squirters in the carbs, everywhere. sounds like you might have either a check valve not working or the pump diaphragm itself could be bad/stretched.

 

[lightbulb140]

Whats this inline jet that ive read about on other posts? could that be the issue? and is the on the inlet or outlet side of the pump?

 

[Strizzo]

there is a check valve in the line that wraps around the back side of the PTO carb, then it Ts off to the two carbs. the jets i was talking about are where the fuel squirts into the carb.

 

[racerxxx]

In Line Jet

http://www.seadooforum.com/showthread.php?60659-99-Challenger-accelerator-pump-question

 

[lightbulb140]

When i get home im going to check that small inlet hose with the jet in it cause i dont recall cleaning that when i did the carb rebuild. Also on the outlet line there is a small green "filter?" thing not sure what it is. If someone could let me know what that bad boy nis that would be awesome. I find it easier to fix things if i understand what all the parts are there for and how they work.

 

[Sportster-2001-951C-Stock]

Make sure the diaphragm plunger can return to it's stop, the linkage lever should have just a hair of play in it when the throttle plates are in the idle position. Adjust acc pump lever stop screw as necessary to gain a hair of play. You should be able to push the plunger lever and get the accelerator pump to draw fuel from the fuel source. There's a port on the carb diaphragm side where acc pump draws the fuel. If the carb diaphragm area is empty, the acc pump will just draw air, so the fuel has to be there in the diaphragm cavity before the acc pump can work. Remove the acc pump from the ski and connect a tube from it into a gas can for testing, the acc pump diaphragm won't work well if it's got a hole in it, so put some pressure on the inlet and plug the outlet to test for a leaky acc pump diaphragm, a couple/few psi with your pop-off pump is enough, and watch to make sure the pressure holds.