View Full Version : Sucking Air

08-22-2008, 11:40 AM
Need some help, I have a 01 Javelin Venom & I have started having trouble with the motor. It sounds & feels like the boat is sucking air instead of gas. I have replaced the filter twice & its still acting the same. The boat wants to go but it seems like the gas is just not getting to the motor for some reason.
I can prime the bulb & the boat will start on the first turn just like it always has. Note, the bulb does not go flat it just goes soft to where you have to prime it again.:confused:
Anybody got any ideas, i have looked over the fuel lines but dont see any cracks or holes in the line anywhere. Do you think I could have gotten 2 bad filters???

The boat will try & go get um but like I said the boat acts like it is sucking air, I was gonna replace the gas lines this weekend but wasnt sure if that would fix the problem or not & I dont have the $$$ to take it to the local shop
So if anybody has any ideas please let me know

Thanks, Chris

08-22-2008, 12:05 PM
Have you used gas with ethanol in it? That could be the problem if so.

Barnacle Bill
08-22-2008, 12:37 PM
First of all its normal for the primer bulb to get soft (but not collapse) when the motor is running. When it starts to act up, pump the primer bulb. If it acts like it wants to go, rebuild the fuel pump. What kind/size of motor is it? I believe they normally put Johnsons on those boats.

08-22-2008, 01:13 PM
I had this same problem with a smaller outboard. It was a hole in the fuel line between the bulb and the motor. It wouldnt leak gas but would suck air and motor ran terrible. Hope this helps!!

08-22-2008, 01:15 PM
Might also check your fitting where it hooks to motor. They will also wear out.

08-22-2008, 01:17 PM
Correct, it is a 90 Johson!!! never had a problem with it till now. The boat acts like it wants to go, it just wont go. Sometimes it will catch & run fine for a few minutes & then it will start again.

I am going to replace the gas lines this weekend, just hoping its not the pump

08-22-2008, 03:40 PM
I have had the primer bulb go bad and it would act like that. The check valve in the bulb may be bad and not holding pressure like it should. I would replace the bulb and lines and see if that cures the problem.

08-22-2008, 03:40 PM
You're on the right track. Replace the lines, bulbs and connections. Might change the fuel filter while you're at it. Probably fairly old anyway and shouldn't be too expensive. Might save yourself a trip to the dealership. If not, you'll have brand new lines to go with your brand new fuel pump.


08-22-2008, 03:49 PM
On my Johnson I replaced the lines and the filter and it ended up being fuel pump. After I replaced the fuel pump she was rockin n' rollin.

08-22-2008, 04:12 PM
Thanks for the info guys!!!

How much can I expect the pump to run??? & is it something I can do or will a dealership/shop have to do it???

i will let youll know if the lines fix the problem

Barnacle Bill
08-22-2008, 04:30 PM
Fuel pump rebuild kits are cheap (about $20) and its an easy job to do it. BTW, thats a good motor, I use to have one.

08-22-2008, 04:32 PM
Thanks everybody!!!, I am gonna try the gas lines first since I have already bought the lines.

I am off for the weekend & I dont have a computer at the house yet so I wont be ableto respond until Monday, but I will let everyknow what happens hopefully I will be fishing by tomorrow evening:eek:

Slipped Cork
08-22-2008, 05:40 PM
First of all its normal for the primer bulb to get soft (but not collapse) when the motor is running. When it starts to act up, pump the primer bulb. If it acts like it wants to go, rebuild the fuel pump. What kind/size of motor is it? I believe they normally put Johnsons on those boats.

I agree.By doing this simple task will tell for sure if the fuel pump is going bad.

08-22-2008, 06:35 PM
Fuel pump

Arkie John
08-23-2008, 12:51 AM
Before tearing into the fuel pump etc, I'd make sure my gas cap is venting properly. One way you can do this is to loosen it slightly and if the motor perks up then I'd give that cap a good cleaning, making sure the vent hole is unclogged.

Now if that does not do it, check the hoses. Take 'em off the tank and the motor, drain the fuel, plug one end and fill it with compressed air. Have the hose and the bulb submerged so you can see tell-tale air bubbles. If the hose and bulp check out, THEN

I'd go with the fuel pump rebuild. You might try youtube for some starters on how-to do it. You'd be surprised what's there. If not, maybe the parts place will cut you some slack and explain how to do it. I don't know about a Johnson, but mine was just a matter of replacing a little diaphram.

Be systematic in your approach and eliminate each item, one at a time. You'll do just fine. :)


08-23-2008, 08:55 AM
I would change all lines. I have had 2 to do that. And on both it was the line under the hood of the motor. Also change out the oil lines. Lots of motors blow up. And people think its the oil pump. but they have a bad oil and gas .
Also some times it will be and can be the line after the oil pump. And if so you will blow it up fast.
So please change out or check all lines.

Darryl Morris
08-23-2008, 02:07 PM
Could be anything, hose, connection, clamp, bulb, etc. from the pickup tube in the tank to the fuel pump. I just got my new Blue Wave back from the factory a second time. Had to replace the pickup tube in the gas tank. She'd run with a full tank but anything less was a no go. On my old boat it would sometimes do exactly what you described. Our conclusion was heat related. On hot days the rubber hoses would expand and allow a little air to enter the lines. We replaced all the clamps with regular hose clamps and then ran a couple of cans of Sea Foam to clean the injectors. This has helped some but did not completely elliminate the problem. No problems when engine was just warm on cooler days.

08-23-2008, 03:07 PM
If possible borrow a tank and hose and run it. That will tell you if it is the tank/hose or in the motor.