fuel line bulb stays soft --help

XMAN · Post by **XMAN** » Thu Sep 04, 2008 5:24 pm

i have a 40 hp tohatsu with maybe 30 hrs on it--i start it with fresh gas every 2-3 mos when not using--its 5 yrs old--i noticed twice last year and last nite as i launched that when squeezing the primer bulb it would not get hard after atleast 20 pumps--i started it up and it ran at idle and in gear very rough, like it was either straving for gas or flooding out--i idled out and slowly accelerated into full speed, stumbled abit and traveled at full speed for about 8 minutes--then slowed down and idled to my spot running abit rough--i kept the idle speed up abit to help so it would'nt die--i put new o-rings in the slip fittings but they are not the exact size as stock--there is no gas leaking anywhere, tank or motor--it has never been adjusted for anything, went from box to the boat--1st 2-3 yrs it was perfect--good troller too--i read on outboard forums it could be a fuel pump leaking fuel into crankcase when pumping---any suggestions thx----xman

GW · Post by GW » Thu Sep 04, 2008 5:30 pm

I would replace that fuel line first and see if the problem goes away.

Ken C. · Post by **Ken C.** » Thu Sep 04, 2008 6:12 pm

Must - Fight - Urge!!! - - - - -

Drop a Viagra in the tank!!!

Sorry, I couldn't help myself...

X, - Start with the simple stuff first. It could just be the check valve in the bulb itself. Don't bother with the Wally-World cheap-o model. Get a factory replacement if possible or one form a Merc, Yammi or JohnRude. Start there. It could be the internal pump check valve/needle. If it's blowing alot of smoke that's a good indication that excess fuel id getting in.

XMAN · Post by **XMAN** » Thu Sep 04, 2008 7:05 pm

ken, it is not blowing any smoke--i took off motor end of hose and pumped it about 4 times and bulb got hard unconnected--also how would bad check valve in bulb cause poor idling--X

thejerbs · Post by **thejerbs** » Thu Sep 04, 2008 7:38 pm

make sure that your tank is venting properly.

fish_food · Post by **fish_food** » Thu Sep 04, 2008 7:46 pm

Ken C. wrote:Must - Fight - Urge!!! - - - - -

Drop a Viagra in the tank!!!

...better throw in the latest issue of Juggs for good measure

fourbizzle · Post by **fourbizzle** » Thu Sep 04, 2008 8:28 pm

first guess would be an air leak somewhere between the tank pickup and fitting on the motor. most likely the hose at a connection point, sun baked area, or the bulb itself.

blkdog812 · Post by **blkdog812** » Thu Sep 04, 2008 8:35 pm

sounds like bulb is bad. replace it with a ny factory one, dont buy a cheapy

Bill K · Post by **Bill K** » Fri Sep 05, 2008 10:40 am

Nine out of Ten times it is a bad bulb, inner valve leaking. Replace the bulb and/or complete fuel line and make sure connections are tight and not leaking. Bill K

Greg_Cornish · Post by **Greg_Cornish** » Fri Sep 05, 2008 11:30 am

Hey guys, he said it gets hard when he closes to line to the engine.

civicrr · Post by **civicrr** » Fri Sep 05, 2008 11:19 pm

check reed valves???

saw a post on another forum with similar problems. turned out to be a bad reed valve.

Ken C. · Post by **Ken C.** » Sat Sep 06, 2008 4:20 pm

X - - Well it could be a fuel pump issue given that it pumps up with the line disconnected. Is this engine fuel injected? Have you taken the cowling off to look for any fuel leaking out?

As for the reed valves, a little extreme for a motor with only 30 hours on it but that could certainly cause a rough idle/rough running condition, but it would have nothing to do with the primer bulb staying soft after 20 pumps. It sounds like it is running OK at speed??

If you are certain you aren't sucking air from the tank, then it sounds like either a leak or bad check valve/needle downstream from the bulb (between the bulb & the motor).

If you aren't blowing alot of smoke then I don't think you are puddling gas into the motor/block, it sounds like it should be leaking out someplace or possibly recirculating back to the tank if there is some type of bypass line involved. A good visual with the cowling off while squeezing the bulb might show you something. If it can suck air in through a crack or loose fitting then you should see signs of gas leaking out.

As for the bad bulb issue, if the internal check valve is leaking you will have pretty much the same symptom you are describing alot of the time. If the bulb's not pushing the fuel up to the motor the fuel pump has to draw all the way up from the tank. Then it gets into a gravity battle between the fuel pump and the gas tank and you have a hard start/rough idle issue.

XMAN · Post by **XMAN** » Sun Sep 07, 2008 9:14 am

thx for all of the responces guys--heres what i've done and what is happening--i found the idle bolt and upped the idle a bit and runs abit better, it was really chugging before--with cowling off no leaks are found anywhere, at tank, on motor or slip fittings--i usually drain all gas when i know i won't be using for awhile so when i started it up after 2 mos. i think i wasn't pumping enough gas to it when the bulb wouldn't get hard--so i think lack of gas and low idle with a soft primer bulb may have caused this--i will be replacing the fuel line assembly, aleast the bulb for sure--also it is not fuel injected and was told to set idle with prop in tank or in water to create backpressure so i will watch that--i'll change the easy stuff, if that dont do it i'll take it in--thx again-----xman

XMAN · Post by **XMAN** » Sun Sep 07, 2008 9:27 am

just another note,ken you said the fuel pump could work harder due to gravity, that may be true-- i was reading on another forum and a mechanic had addressed a problem simalar to this and said on mercury motors to make sure the bulb is pointing upward to the motor he didn't know why but the guy said it worked better when he did it--i'll be arranging my lines accordingly, it cant hurt----xman

Bill K · Post by **Bill K** » Sun Sep 07, 2008 4:02 pm

Just a sidenote, the bulb is directional, in that there is a arrow on the bulb and this should be on the engine side or pointing towards the engine. That may be what the mechanic meant by pointing to the engine. That way the valve inside is working so fuel can not flow back towards the tank and therefore causing or allowing the bulb to go soft. Bill K

XMAN · Post by **XMAN** » Sun Sep 07, 2008 4:47 pm

BILL K. susanville huh, i used to live there in the mid 70s while going to lassen college--had a good time, i have acouple of friends living in janesville and almanor-----xman

WELDER DUDE · Post by **WELDER DUDE** » Sun Sep 07, 2008 8:08 pm

I had this prob, the reason the bulb needs to be pointed up is becuase the check ball wont seat to hold the vacume. point arrow on the bulb up if all else dident work

Bill K · Post by **Bill K** » Mon Sep 08, 2008 5:43 am

XMAN wrote:BILL K. susanville huh, i used to live there in the mid 70s while going to lassen college--had a good time, i have acouple of friends living in janesville and almanor-----xman

Xman. Still not bad area to be in, however the prison's have really made the area, not as nice, as back a few years. Many new face's and most are not the same friendly people that lived here. Fishing is good i.e. Almanor, Antelope, etc Afraid of their own shadow, if you know what I mean and so forth. Say hello if you are up this way. I am up on Eagle lake road in the Lake forest area and in the book. TIght lines and stay well. Bill K