Cam gone bad????

[83Twain]

I have a 1983 Mark Twain 16/9 BR with the 4cyl. 140. Its always been a hard to start boat, have to pump the throttle several times to get it to start. But after the first start it will at times start easy. Let it sit for an hour or two and its back to hard starting. Now after a new fuel pump it will not start. I have taken the line off of the carb and there is no fuel to the carb. Since I bought the boat a few years ago I have done the following: rebuilt the carb, added electronic ignition, cap and rotor, plugs and wires, rebuilt starter and new fuel line from the tank to the pump. When i changed the fuel line I did remove the anti siphon vavle and it seemed to move freely. Can they go bad and still move? Has anyone heard of the cam lobe going bad to the point it can't move the lever enough to pump? I have read the sticky thread about fuel system analysis. Don't see buying a tool I will only use once.

Any input is greatly appreciated!

Thanks

 

[searay3]

Re: Cam gone bad????

Check to make sure the fuel pump lever is under the cam. It is easy to get it above and it won't pump.

 

[zbnutcase]

Re: Cam gone bad????

Never in my whole life have I seen a flat pump lobe.

 

[JustJason]

Re: Cam gone bad????

Don't see buying a tool I will only use once.

Then take the boat in and pay somebody who has the tool. I wrote the thread you read on the fuel system, i know exactly how to test it, and I wrote it all down to the best of my ability. If you want to diagnose, you need tools.

Also agree with zb, chances of having a bad cam/lobe is like .01%

 

[6meter]

Re: Cam gone bad????

Bad install or bad pump.

 

[83Twain]

Re: Cam gone bad????

OK, I will buy the tool. Something just doesn't make sense. The pump does pump so I know I didn't install it wrong. It just doesn't seem to able to get the fuel to the carb. So is there something in the pick-up screen? Can the anti-siphon vavle go bad and just alow a little fuel to get past? I did remove the steel line to the carb and it is clear. The vent tube "was" open at the begining of the saeason when I filled up. So maybe a bad pump? Going to run a fuel line to a gas can and see what happens.

Thanks