Suzuki DF50 suddenly runs rough & stalls

rschnog

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Jan 7, 2004
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Hello all, this is my first post.<br />I have a Suzuki DF50 of appr. 1year old. Maybe 100 hours total. I take very good care of the engine. I don't use it every week but let it run (water hose connected) at least once a week.Fuel I keep fresh. I did add gas stabilizer from Cyclo" to the fuel last month (seasonal storage amount, as discribed on the container)to be sure it would stay fresh.<br />Last time i took the boat (13 ft bostonwhaler sport) out the engine started fine, ran fine in warmup but hessitated and almost stalled when i opened the throttle. With throttle half to three quarters open it would run as if on 2 cilinders and occasionally pick up speed for a few seconds and pur like a kitten,like it normally does. Then fall back and almost stall. I would try this a few times and at the same time pump the gas to the engine with the fuel line handpump to see if it was lacking fuel.No difference. Now I do always spray the entire engine (under the cowling) with silicone spray (generously) after each boating trip and suspected that maybe to much silicone could have fouled electrical contacts to the computer and or the injectors and ignition coil power supply. I've cleaned all these connections with contact cleaner and see no difference.<br />The engine check lamp does not indicate anything either.<br />know of anything else that could be the cause?<br /><br />greetings,<br /><br />Robert
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Suzuki DF50 suddenly runs rough & stalls

Ahoy, Robert.<br /><br />I wouldn't recommend even an experienced wrench work on that engine without a factory manual.<br /><br />I don't have a manual on the DF50, but my first inclination would be to examine the vapor seperator and any fuel line connections for air leaks.<br /><br />Good luck. :)
 

clanton

Rear Admiral
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Jul 9, 2001
Messages
4,876
Re: Suzuki DF50 suddenly runs rough & stalls

If the engine is fuel injected and has a fuel seperator( I cant remember anything) drain the fuel from the seperator into container and look for water and trash. The trash very small, may be light brown in color. If lots of trash you need complete fuel system cleaned. You could also drain the fuel rail at the injectors and look for trash.
 

maclavin

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Nov 11, 2003
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Re: Suzuki DF50 suddenly runs rough & stalls

Might have too much oil in motor .<br />Drain extra oil and change the plugs.<br />Found 3 motors last week with the same problem.
 

rschnog

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Jan 7, 2004
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Re: Suzuki DF50 suddenly runs rough & stalls

Thank you for your suggestions.<br />I will check them all out and let you know the results.<br /><br />Robert
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: Suzuki DF50 suddenly runs rough & stalls

You may have a problem with the electric fuel pump on the high pressure side. Hook up a pressure gauge to the system according to the manual and run the engine. I'll bet you will find surging pressure due to a pump related problem, including a gummed up intake screen on the bottom of the pump.
 

rschnog

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Joined
Jan 7, 2004
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Re: Suzuki DF50 suddenly runs rough & stalls

Solved !<br />Hello again,<br /><br />I have tried all the above suggestions and could not find anything wrong with the engine.<br />Then suddenly it dawned on me that the injectors could be fould (the fuel here does tend to foul up injectors in fuel injected automobile engines after years of use. As the engine sits idle for a week each time I tought the fuel could have fould the injectors. Especially in the past when the fuel was even worse here it would easily foul even carburated engines carburators within a year. Mostly gum like red residu. I added carburator / fuel injector cleaner to a small auxiliary tank I have and saw almost imediate relief in the engine as this new treated fuel past true the injectors. Letting the engine run in a tub of water for aprrox. 20 minutes solved the problem. I have not water tested the engine yet but it already runs very smooth, like it used to .<br /><br />Thank you for all your suggestions,<br /><br />I guess I gained confidence again in the engine as it had no fault in this case.<br /><br />Robert
 
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