bad gas cap gasket

[EBBTIDE 78]

Would a bad gas-cap gasket cause a low pressure condition on the suction side. I have a 77' - 70hp Evinrude. The motor will start up, warm up, & run great 90% of the time. After getting to a prticular fishing spot on LaSalle Lake in LaSalle Il. & catching 60 or so Yellow Bass we decided to move on. The motor would start up and idle fine for a min. or so, but when trying to accelerate the engine would bog and die. Trying the second time same result. Went to check the bulb and it was not completly hard. Pumped it up firm and motor started and ran just fine. I did check today for leaks and there were none. All connections and gas lines have no leaks. But I did notice the bulb again was semi-hard. I was told this could be a "lean condition". The floats need to be checked. And that I should have the carbs. checked, to cure this problem.

 

[KYHunter2]

Re: bad gas cap gasket

Check your tank vent , be sure it is not plugged / closed whatever. <br /> If theres no way for air to get in tank. It will cause symptoms like yours. <br /> Make sure the bulb is working all the time, check valve could be sticking. <br /> Really just go over whole fuel system . It sounds fuel related. <br /> Try squeezing bulb when it acts up. If it gets better check bulb and fuel pump. <br /> Really does sound like a fuel pump, bulb or vent problem. <br /> The bulb should stay hard , for a good while. But it will get soft , gradually, over time. <br /> I check mine , whenever I fish at 1 spot, for very long.<br /> <br /> Also, if you do decide for whatever reason . To have carb floats "checked" buy rebuild kits and do them . Might as well, you'll have them off, and apart anyways. <br /> <br /> Dont forget to check fuel filter . <br /> <br /> KYHunter <br /> <br /> P.S. I believe , the cap gasket ,is mainly to keep water out. Most have a vent on top, that needs to be open.

 

[R.Johnson]

Re: bad gas cap gasket

There seem's to be alot of confusion about these primer bulb's. When the engine is running, that bulb is just a passage in the fuel line. It should not stay hard. Fuel is pulled through it by the pump, and through it's check valve's. It is not forced through by pressure, so there is no reason for it to stay firm.

 

[OBJ]

Re: bad gas cap gasket

To add a little to RJ's post, the check valves in the primer bulb have been known to fall apart, leak thru. If this happens and you stop for a good while, it's possible the fuel normally trapped between the fuel tank and engine can flow back to the tank.<br /><br />Simple primer bulb test.....empty the fuel line and primer bulb and shake the bulb. If you hear/feel something rattling around in the bulb, probably one of the check valves have fallen apart. Sometimes you can feel the ball by squeezing the primer bulb flat with your fingers.