Logo
FULL SITE MENU

b89 90hp outboard starvation issues

E

erzulie

New member
"I have a VERY low hours 1989

"I have a VERY low hours 1989 Mercury 90hp that has new fuel pump, gas tank, inline filter, and hoses. Carbs rebuilt and cleaned less than 20 running hours ago. starts and idles fine, revs up and down in nuetral fine, under tourque load (in gear) it starts to starve itself above 1500 rpm- if someone sits there and constantly squeezes the primer bulb it works fine at all rpm ( in gear or not), but when you stop squeezing bulb at high rpm she sputters and chokes out- you can feel the bulb soften and see the inline filter empty out- until you start priming the bulb again- HELP! redfish are running and Im missing them!"
 
"It sounds like your "new&

"It sounds like your "new" pump is sucking as much gas as it can (from the fuel filter and the gas line).

So, you may have the issue back at the tank end. A blocked vent, malfunctioning anti-syphon valve, partially clogged pick-up could be restricting the flow. While the pump sounds to be decently strong, it can't suck the gas up at an adequate rate for higher rpm operation...."
 
"compression test, the pump wo

"compression test, the pump works on the compression cycles, and maybe a stuck check valve in the pump"
 
"Graham- good thoughts, I went

"Graham- good thoughts, I went back into the tank this weekend and checked pick up, vent hose and vent- all looked okay, just to be safe I replaced all the above deck and vent hose and bought a new fuel fiting for the engine end of it and replaced primer bulb with new- seemed great when I hooked up to fresh water hose and ran in nuetral, but then again it always did in nuetral, the issue was in gear and under load-. didn't get chance to launch, test is next weekend.

JB- never done a compression test before (aside from when I purchased engine and had mechanic do it) is it something I can do myself? just put in a rebuild kit for the pump, pretty sure i got it right, so don't think its that."
 
"ps: thanks for posting so qui

"ps: thanks for posting so quick and with such good feedback, this is my first time using a forum and you guys rock. fish on."
 
Back
Top