All right, I know darn good and well with all these Ford truck guys out here, I'm sure quite a few of you have fishing boats. I've got an two-stroke 115hp Merc. with three carbs...problem is, the bottom carb is dumping fuel out of the air intake. Float stuck? Another problem? Any ideas would be helpful!

 

Float stuck or the rubber seat that the float needle seats into is bad.

 

yea i would say float/needle, seat as well, my 9.9 kicker did the same thing. get the serial number off the engine and then go to www.mercurymarine.com go the parts section and you can put in the ser. # and order a float/needle and seat kit

 

Thanks guys!

 

inline six right? is it dumping out or spitting out? possible might be bad reed valve if it just spitting out. if it is dumping out try tapping the top of the carb were the two little bolts and little black hose are and see if the needle dont come loose even if that works it is probably still time for a carbs to be rebuilt. if you do your self take your time and note how the needle goes in. those inline carbs are a real pain.

 

Please define dumping or spitting...All three carbs were rebuilt last September by the mechanic I had been going to...and this was the last straw for me. I bought this boat, took it to him and told him I wanted it ready for the water when I got it back. So he rebuilt the engine ($1700), I went to the lake and no steering (cables were all bound up, not a boat mech. but this seems like something I would have at least looked at)...boat goes back to shop for three weeks($400). I get the boat back, go to the lake, and need to get towed in...bad gasket on the water jacket, back to the shop (warranty). Two weeks later, I'm back on the water and towed in again...bad ignition control module($150). Three weeks later, on the water, boat stops...towed in (gas tank is rusting on the inside and clogs up the carbs, again I'm not a mech. but I think I would have looked at the tank prior to sending the boat out) so I get a new gas tank ($120) and the carbs rebuilt. Go to the lake, and the bottom carb is dumping fuel...I pull the boat out, winterize it and put it away for the winter. I know a used boat will always have a few gremlins, but I don't think I'll be going back to the mechanic anymore!

 

if i were you i would never take any thing back to that so called boat mechanic boat engines are one of the easyiest engines that i have worked on. i have rebuilt powerheads and fixed lower units and all the guys at work have done the same and we have never had a engine come out of the shop like the one that you described. and we have had some really messed up engines come in the shop. but any way it sounds like you need to rebuild your carbs yourself, and when you have the carbs off check the reed valves and make sure none of them are stuck shut. but take your time rebuilding the carbs if you have never it before there are small parts and it is easy to get confused

good luck

 

well is gas just pouring out of the throat or just spits out when running. on that particular engine the reed valves are internal and requires splitting the crank case half and pulling the crank to check. any ways sounds like you mechanic or what ever he is has got the not sure of the correct name but there little pieces of metal that got like a float pin in them there are two of them the float does not have a pin threw it it slides up and down in a bore and pushes against the metal arms to close the needle. any way sounds like there in backwards almost bet money on it in fact. you can pull the cover off 2 bolts 5/16 socket i belive then pull one that aint leaking and compare. oh one more thing check your compression very easy to brake a ring when assembling those motors. let me know how ya make out

 

The gas spits out when the engine is running so that would be the reed valves right? I know this is a stupid question, but how different is a two stroke carb vs. a four stroke? I've rebuilt carbs on my four wheelers and on mowers, but I haven't messed with any two stroke stuff...

oh yeah, do the three carbs need to be synchronized?

 

if you rebuilt a lawnmower carb you can do a out board carb just keep track of the way it came apart yes the carbs need to be sinked with the throttle althe way closed loosen all 3 screws on each carb on the black linkage inbetween them make sure all butterflys are closed push them closed with a screw driver then tighten the screws back starting with the bottom carb first then work your way up. then open the throttle up and look to see if all butterflys are opening the same

 

I have to disagree, a 115hp outboard isnt the same as a lawnmower. These units run some pretty serious RPM under fairly heavy loads compared to other types of engines. They also produce fairly high HP per cubic inch. A carb set too lean will melt a powerhead pretty fast. A new replacement motor will cost you about $10k.

Over the years, I've rebuilt carbs on trucks, snowmobiles, motorcycles , I/O boats and small outboards (>10hp) I won't touch a bit outboard though ( I have a 115 johnson and a 60 evinrude

Big outboards (especially mercs) have a ton of special tools and procedures for just about everything. Not to say you cant do it yourself, just that mistakes can be very expensive and/or dangerous. Find a good merc dealer and bite the bullet to get it fixed right. Also get a good marine inline fuel filter.

 

then you can come work on mine i have a 30 horse johnson with water spitting out the exhaust and bubles coming from the water intake it will runn for a few seconds then dies ??????????????

 

yes a carb set to lean will burn a piston up so and a piston will burn up on any thing elese to if it is running lean. never said a out board and lawnmower were the same said if he has rebuilt a lawnmower carb he can build a outboard carb. l