Fuel Pump? '86 Evinrude 140

[Brew]

Well, I'm running out of ideas.<br /><br />My '86 Evinrude 140 stalls most times when I try to accelerate. I'm reasonably sure it is a fuel related problem because I can sometimes get it up on plane if I choke it as I accelerate. If I do get the RPMs up enough to get on plane, everything seems fine. I can adjust speed up and down without a problem as long as I stay on plane.<br /><br />I've rebuilt/cleaned the carbs (several times), replaced the fuel line/primer bulb, replaced the inline fuel filter, checked all fuel line connections, checked the timing, did a link & sync and replaced spark plugs. <br /><br />The only two things I can think of that I haven't ruled out are the anti-syphon valve and the fuel pump.<br /><br />Can you remove and subsequently replace the anit-syphon valve if it turns out that it isn't the problem? Anything special about removing it?<br /><br />The fuel pump is the infamous VRO. I don't wish to start another debate about the merits/shortcomings of the VRO system, but I would like to know if a fuel pump that was starting to "give up" would perform adequately at high RPM, but not at lower RPM while accelerating? How would one test the fuel pump?<br /><br />If I did end up replacing the fuel pump, I understand the fuel/VRO combination pumps are quite expensive. Are "non-VRO" fuel pumps quite a bit cheaper? If so, how would one determine the appropriate non-VRO pump to purchase?<br /><br />Thanks in advance.<br /><br />Brew

 

[Dhadley]

Re: Fuel Pump? '86 Evinrude 140

The problem still lies after the pump. You mentioned that you rebuilt the carbs - did you install new kits? What brand? You mentioned new spark plugs - what brand and number? Is the fuel fresh? What type of boat? Does the bow raise very high on take off? Whats the top rpm with an average load? What do you have the timing set at wot?<br /><br />Very important - are you running with the airbox cover on or off?<br /><br />I know thats a lot of questions but take your time and answer each one. <br /><br />Good luck!

 

[Brew]

Re: Fuel Pump? '86 Evinrude 140

Dhadley,<br /><br />Thanks for the response.<br /><br />I did install new carb kits, bought from the dealer.<br /><br />Spark plugs were Champion 77JC4 (I'm at work, so I haven't the number in front of me, but it was definitely a "77" with a "4" on the end).<br /><br />Fuel was stabilized last fall. I doubt that is the source of the problem though as I was having trouble prior to putting boat away last fall and the gas was fresh then.<br /><br />The boat is a 17 foot Invader bow rider. The bow can rise high, but not excessively.<br /><br />Top RPM with an average load is around 6300.<br /><br />Timing is set at 18 BTC at WOT. <br /><br />Definitely running with air box cover on.<br /><br />Am I correct in assuming that if I can run at higher RPMs, that my fuel pump is not the source of my acceleration/stalling problem?<br /><br />One more thing I noticed yesterday as I was putting boat away. I tried pumping the primer bulb a little excessively to see if I could spot any fuel leaks. The lower right carb did leak fuel if I really put some pressure on the bulb. I removed the carb and checked the needle valve, seat and float, but everything seemed in order.<br /><br />Any thoughts on where to turn next would be appreciated. I'm stumped.<br /><br />Thanks,<br /><br />Brew

 

[Dhadley]

Re: Fuel Pump? '86 Evinrude 140

Good info.<br /><br />The plugs are good. I would get rid of the fuel - regardless - if it were mine. The rpm is good, the timing could stand to go to 20 (with fresh 87 octane fuel). The float level is critical, make sure its right. Keep the airbox cover on.<br /><br />Double check the side plate cover and gasket on the carbs. They can suck air there. Use fender washers under the screw heads to cover more area if needed. You say the kits were from a dealer so we are assuming you mean they were E/J kits. <br /><br />Two things - <br />1- When you have a boat that has a lot of bow rise the fuel in the bowl can actually move back away from the pick up tube and cause a momentary "bog". Thats why the float level is critical. We actually fooled around with float chamber stuffers and different bowl gaskets. You can also install crossflow needle and seats. They have a much larger opening in the seat. A fin on the anti ventilation plate (lower unit) helps too.<br /><br />2- The carbs were calibrated for fuel we had in 1986. Its not unusual to have to rejet for todays fuel. Especially if you use high test and not regular. I would make a big change in the mid range jets and test. Go 5 or 6 numbers smaller to richen up the mid and test. If it helps then you are going in the right direction.<br /><br />Hope that helps some.<br /><br />Good luck!