Warranty problems Suzuki DF 115

HDR-Project

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Sep 4, 2004
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During garanty period after 480 hours of operation a problem was noticed by the crew of our research boat: Oil mixed with fuel. Observation results: 1 litre fuel in the oil per 50 - 70 hours of operation. The problem could not be solved by exchanging high pressure pump and pressure regulation module.<br />The problem is not accepted as a case of warranty by the gerneral dealer of Suzuki Spain (Movil Motors S.A.) and the local dealer on Tenerife (HERZOG.S.L.) because the engine is operating normally and the electronic alarm control does not registrate any problem.<br />Is there anybody, who knows about similar problems of this engine. What is the reason of this problem and how to repair?<br />Volker Todt/Project management
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Warranty problems Suzuki DF 115

Howdy, Volker.<br /><br />Welcome to iboats. :) <br /><br />This is the first case I have heard of this problem occurring in a Suzuki 4 stroke, though it has been fairly common in Yamaha and Mercury 4 stroke engines, paticularly when fairly new.<br /><br />Yamaha's investigation of the problem in their engines concluded that it was caused by incomplete warm up of the engine after starting, the engine running rich after reaching a stable, but too low, operating temperature and incomplete seating of piston rings.<br /><br />Their solutions, which appears to be effective in eliminating the problem, included thorough warmup after starting, a more strenuous break-in to more completely seat rings, avoidance of synthetic oils during break-in and replacing the thermostats to bring engine temps above the threshold at which the computer leans engine mixtures.<br /><br />Some, or all, of these measures might well help deal with your problem, though I imagine that 750 hours of operation should have satisfactorily seated rings and seals.<br /><br />I hope this information helps. Please keep us advised of results.<br /><br />Because this is actually an engine trouble I will move it to the Suzuki Troubles and Repair forum.<br /><br />Good luck. :)
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Warranty problems Suzuki DF 115

hello<br /> te early suzukis had some fuel dilution problems due to over cooling. there are some cooling system mods that were made. have your dealer test your cooling system and look up all applicable tech bullitins. maybe fridays Marine will see this and shed some light.<br /> they are good folks at Fridays.<br /> good luck and keep posting
 

lakensea

Chief Petty Officer
Joined
Jan 30, 2002
Messages
542
Re: Warranty problems Suzuki DF 115

High pressure fuel pump & regulator would have absolutely nothing to do with fuel in oil situation. First thing you should do is find a dealer who knows what they are doing with fuel injected engines. You need to have a leakdown test done on the engine to check the ring seal. Usual cause is inproper new engine break-in, prolonged periods of idling or improper type/grade of oil. Has this been happening since new or is it just occuring? If it just started happening you may have a stuck thermostat or pressure reflief valve causing the engine to run cold. You also may have a pinhole leak in the low pressure fuel pump diaphragm.
 

HDR-Project

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Joined
Sep 4, 2004
Messages
8
Re: Warranty problems Suzuki DF 115

Originally posted by JB:<br /> Howdy, Volker.<br /><br />Welcome to iboats. :) <br /><br />This is the first case I have heard of this problem occurring in a Suzuki 4 stroke, though it has been fairly common in Yamaha and Mercury 4 stroke engines, paticularly when fairly new.<br /><br />Yamaha's investigation of the problem in their engines concluded that it was caused by incomplete warm up of the engine after starting, the engine running rich after reaching a stable, but too low, operating temperature and incomplete seating of piston rings.<br /><br />Their solutions, which appears to be effective in eliminating the problem, included thorough warmup after starting, a more strenuous break-in to more completely seat rings, avoidance of synthetic oils during break-in and replacing the thermostats to bring engine temps above the threshold at which the computer leans engine mixtures.<br /><br />Some, or all, of these measures might well help deal with your problem, though I imagine that 750 hours of operation should have satisfactorily seated rings and seals.<br /><br />I hope this information helps. Please keep us advised of results.<br /><br />Because this is actually an engine trouble I will move it to the Suzuki Troubles and Repair forum.<br /><br />Good luck. :)
 

HDR-Project

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Joined
Sep 4, 2004
Messages
8
Re: Warranty problems Suzuki DF 115

Thank you for your advice. I will stay in contact until problem is solved
 

HDR-Project

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Joined
Sep 4, 2004
Messages
8
Re: Warranty problems Suzuki DF 115

Originally posted by rodbolt:<br /> hello<br /> te early suzukis had some fuel dilution problems due to over cooling. there are some cooling system mods that were made. have your dealer test your cooling system and look up all applicable tech bullitins. maybe fridays Marine will see this and shed some light.<br /> they are good folks at Fridays.<br /> good luck and keep posting
 

HDR-Project

Cadet
Joined
Sep 4, 2004
Messages
8
Re: Warranty problems Suzuki DF 115

Originally posted by lakensea:<br /> High pressure fuel pump & regulator would have absolutely nothing to do with fuel in oil situation. First thing you should do is find a dealer who knows what they are doing with fuel injected engines. You need to have a leakdown test done on the engine to check the ring seal. Usual cause is inproper new engine break-in, prolonged periods of idling or improper type/grade of oil. Has this been happening since new or is it just occuring? If it just started happening you may have a stuck thermostat or pressure reflief valve causing the engine to run cold. You also may have a pinhole leak in the low pressure fuel pump diaphragm.
 

HDR-Project

Cadet
Joined
Sep 4, 2004
Messages
8
Re: Warranty problems Suzuki DF 115

Hallo,<br />I noticed the problem after 480 hours of operation, In fact the dealer tried to solve the problem by taking out the thermostat, also the low pressure pump was completely exchanged. I will follow the other advices, thank you very much. <br />On the Canary Islands is only one Suzuki dealer that's the problem.
 

fridays

Petty Officer 2nd Class
Joined
Jan 26, 2003
Messages
126
Re: Warranty problems Suzuki DF 115

The problem is as JB pointed out. Rare in a 115 and more common in lower HP engines. Put a hotter thermostat in it ( 72 deg. C instead of 60 deg. C I think) and the problem will most likely go away. Run it hard from time to time.
 
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