Fuel restriction on 200 hp Johnson.
 

Bought a used bay boat recently with a '97 Johnson Ocean Runner. Engine runs fine but the check engine light comes on at WOT. Light goes off after I bring the throttle back to cruise RPMs. Read in my engine manual that is a fuel restriction causing the vacuum sensor to go off. Changed the fuel/water separator filter, checked the fuel filter on the engine (clean), and checked the screen on the pick-up tube and the anti-siphon valve operation. Found no problems, so took it to a shop to draw a vacuum on the lines to find out how much restriction I had and where. Well the anti-siphon has a little over 2 inches of vacuum and the fuel/water separator has about the same. My fuel flow meter draws a little but nothing to be concerned with. Overall, the whole fuel line with bulb is drawing about 5.5 and setting off the sensor. He says he's going to try a new brass anti-siphon valve to see if it helps, but if it doesn't, I have to remove one or the other. Either the anti-siphon or the fuel/water separator. I don't want to remove either one, you have any other suggestions? Thanks for any help.

Check make sure there's no big fuel filter inline that isn't visible. That's usually the culprit. Seen it with clampys and a buddies haynie


"Go ahead, share your opinion! I won't cry"

Fuel water separator. Just to see. Then if it is it then change to a bigger Id port


"Go ahead, share your opinion! I won't cry"

I'd rather not have to run without the separator, but I assume it's safer than running without the anti-siphon valve. What port are you talking about increasing the id on?

Gonna have to check for this also, but pretty sure there isn't one. The guy at the shop didn't mention seeing one either. Why the hell would someone put a hidden fuel filter on a boat like you said? Some real geniuses out there.:confused:

are the fuel lines 1997 also? if so, ethanol could be the culprit and the lines are collapsing. not saying that this is the case but know of it happening.

Nah, they're not the original lines. Ended up removing the screen on the pick-up line in tank, changing the anti siphon valve and removed the engine fuel filter. Dropped the vacuum from over 5.5 to below 4.