Intermittent lean condition

[rohdemedic]

Hey guys, thanks for all of your help in the past.
Rebuilt a 93 evinrude 120 v-4, it had thrown a piston. Took it in for link& sync and to have the carbs set (rebuilt those also). Ran great on the hose. Ran lean in the water and would not idle. Took it back and they enriched the mixture. Put it in the water, ran great idled in gear, no lean sneeze ect. Ran the boat for approx 30 mins variable throttle for break in. Turned off restarted fine. Fished for approx one hour and was right back to lean condition, dying out in idle. Won't idle in gear ect. Driving me crazy. Seems like a fuel problem. What do you think about a check valve or somthing with the fuel bulb. Also additional info, when I went to start the boat the second time (after running and sitting for an hour) the bulb was soft.
Thank you again for all of the help.
Rohde

 

[ondarvr]

Re: Intermittent lean condition

Its normal for the fuel bulb to be soft once the motor is running, you just don't want it to be sucked flat.

Having clean carbs yesterday, or even one hour ago doesn't mean anything and its not uncommon to have some gunk plug a jet after a cleaning. I've had carbs work great for an hour or so after a cleaning and then plug again, it just means I didn't get all the gunk out of the system, remember it doesn't mean there was gunk still in the carb, but in the lines or tank.

Did you ever find out why the piston failed the first time? If you didn't then its possible you'll need to rebuild it again when the same thing happens.

 

[ENSIGN]

Re: Intermittent lean condition

Sounds like bad contaminated fuel from old hoses or primer bulb gone bad,You can't always see the crap,change all the fuel hoses and bulb and install a separator filter.You will most likley have to go through the carbs again

 

[rohdemedic]

Re: Intermittent lean condition

Thanks guys.
Its the on and off again nature of the problem that is confusing me. I drained all of the fuel off during the rebuild. A smarter person than me would have put a filter in prior to hooking it back up. Guess I should go over over the entire fuel system again.
As for the initial problem never solved that one. Don't really know where to start. Was hoping to catch it in the rebuild but nothing was obvious.
Thanks again