'85 Johnson 40hp still surging!

[Tomo]

Hi,<br /><br />My motor is still surging even after I put a kit in the fuel pump, especially at full throttle. I have to pump the bulb to keep it going. I have cleaned and kitted the carbs as well. I've replaced the fuel lines between the carbs only. What else could be happening? The gas can and gas line have not been used for several years. Do I need to replace both of these? <br /><br />Thanks in advance, you all have been very helpful so far.<br />Tomo

 

[fireman 757]

Re: '85 Johnson 40hp still surging!

Sounds like you have a bad line/primer bulb from the tank to the carb. If you have to keep priming it to keep it running you are sucking air somewhere in that fuel line. Wal Mart: about 20 bucks. I prefer OMC parts but that should take care of your problem.

 

[Tomo]

Re: '85 Johnson 40hp still surging!

I bought the new fuel line and the motor is still surging. What could it be? air? carb?<br /><br />Tomo

 

[clanton]

Re: '85 Johnson 40hp still surging!

You could try short piece of clear hose before fuel pump and after fuel pump, look for air bubbles. If power pack has tan wire, disconnect and try it.

 

[almost retired again]

Re: '85 Johnson 40hp still surging!

Hi Tomo,<br />Have you checked the gasket behind the fuel pump? If you can squeeze the primer bulb and keep it running you are manually being the fuel pump. I would think either a bad fuel pump, or a bad gasket

 

[Tomo]

Re: '85 Johnson 40hp still surging!

I'll try that clanton. By the way, what is the tan wire? Where is the power pack on an '85 40 Johnson?

 

[Tomo]

Re: '85 Johnson 40hp still surging!

almost retired...I installed a fuel pump kit yesterday.

 

[fireman 757]

Re: '85 Johnson 40hp still surging!

I'm kind of scared to post this but here goes. It could be an exhaust leak. Take your cover off and run it. If it doesn't surge then you probably have a bad exhaust gasket. It could be cutting back your air at high speed but at lower speeds there is plenty of it.<br />It's worth a try.

 

[fireman 757]

Re: '85 Johnson 40hp still surging!

If it is still surging with a new line make sure that your gas tank is vented or not vented. Your float could possibly be set wrong when you rebuilt your carb. It should be level with the carb when turned upside down. Also double check and make sure that your high speed jet is perfectly clean. Any speck will cause this type of problem also.