Engine bogs at take off..

[bothomas]

Motor cranks and runs fine first thing at the ramp, but at least once per trip after fishing for a while I crank the motor ( cranks fine ) but put in gear and motor boggs and dies. After 3-5 times it will take off and I'm fine.. Runs perfect all the rest of the time. Took to a shop for tune up, plugs, foot oil , impeller, etc. they said probably leaking fuel out of carbs when the motor is up while fishing.....anybody else have this problem?

[carolina-rig-01]

mine did that one time in a tournament takeoff. we were boat 3 and ended up like boat 25 which really p!$$ed me off! anyways it turned out that it was a bad check vaulve in my primer bulb. it was like $7 for the whole to bulb and that fixed the problem. maybe a good place to start since it would be a cheap fix if that did it.

[1FASTLASER]

Older outboards where notorious for that. Most folks trim the engine up while fishing allowing the carbs to bleed off. Also there is the heat that everyone has been dealing with that causes fuel problems. Next time it does that make sure before youfire up that the primer buld is pumped and hard. If it is soft you need to inspect all fuel connections and the tank vent, The tank vent is the only place that it is supposed to be open. Another thing you can do is run some Seafoam through the engine. Without actually putting my hands on it it is somewhat diffucult to pinpoint exactly. If after doing the above mentioned items if there is still a problem it could be time for a carb rebuild before it gets worse. What motor are we talking about anyways????

[bothomas]

Laser, I was hoping to get to talk to ya on this. I know your good with these things... the motor is a 2000 Johnson 175.. I've tried leaving the motor down and checking the bulb and it feels full, I can still pump it, but doesn't help..also if I leave it in nuetral and give it gas it will rev fine, put it in gear and boggs...hope its somthing minor. have a manual on the way so maybe with some advice I can start checking deeper into it this week.

[1FASTLASER]

Ok the first thing that I would do is check fuel tank vent line and make sure that it is not restricted. Then make sure all fuel lines are nice and tight. I then would definately run a good dose of Seafoam and do a real good decarb. Even though your engine is not that old it is possible you have some carbon buildup in the motor or possibly some small rstriction somewhere in the fuel system. What you are explaining is a intermittent problem which is the hardest to find. Running Seafoam will eliminate any restricted fuel passages. Another thing that comes to mind is the fuel line itself. Run your hand down the line and feel for any soft spots that might be in it. If you find an area that doesnt feel like the rest of the line replace it. Fuel lines are known to deteriorate even faster on todays engines due to bad fuel and the additives fuel companies are using such as alcohol. Alcohol will deteriorate a line very quickly and cause the inner linner to start flaking off. If you find a spot that is questionable on the fuel line......follow it to your pump and remove the cover abd inspect the screen. Its very possible you have a restriction there.......floating around causing it to be intermittent. If your engine has a water seperator or fuel filter onit check and/or replace. All these things I have posted will cost ya less than $20. Basically just some time. Holler back at me when you get the time.

[bothomas]

Thanks laser I'll keep you posted...should have time to do the checks this week..

[1FASTLASER]

Anything for a fellow bass fisherman. I really hate the fact that marinas or boat repair shops get into people's pockets like they do so I try to help folks out.

[bothomas]

laser, i've been doing some research on the johnson forum on bbc and think I may have diagnosed my problem.. ever hear of "heat soak"?

[1FASTLASER]

Sure have bud and in the heat that some of us have been dealing with it could possibly be what you are experiencing. Now that you mention it......the fact that it is intermittent makes the possiblity even greater. I personally would still check out what I mentioned just to give piece of mind and help familiarize yourself a little more with the motor. Please dont forget to check that vent. That in itself will help heat soak. Its basically the same thing as what used to happen with older vehicles with carbs. We called it vapor lock then.

[1FASTLASER]

So bothomas inquiring minds wanna know......did ya find anything out yet???????????

[bothomas]

I have... checked the things you mentioned and everything looked fine.. I have checked me primer bulb several times when dealing with this it has always kept it's prime...don't know if i was checking when it had not had time to leak down or what, but last sat. I checked it once before I did anything to start up after fishing for a while...got on some schooling and stayed for about 2 hours in one spot..anyway checked the bulb before ever the key and had lost most of it's prime. have another bulb and should be replacing today and on the water tomorrow.. let you know how it goes with the fish and the boat...thanks laser..

[bothomas]

replaced bulb and still losing prime after fishing. any thoughts, I'm thinking it has to have a leak from the bulb to the motor providing the check valve in the new bulb is working.... Am I on the right track?

[1FASTLASER]

Right off the top of my head yes u are on the right track. Have you checked the fuel tank vent to make sure its not obstructed in any way? After that start from the fuel line attachment and go to the engine. Check every connection and make sure its snug. If still problem persists time to get to the fuel pump and make sure all is tight there. Sounds to me like its a very small problem such as loose fitting. That will cause one to loose prime when shutdown but have enough pressure to keep running after getting started.