suzuki df50, buildup in intake, running rich(pics).

[tjl76evinrude]

this is on my 2005 suzuki df 50 with just under 130 hours. took my intake off earlier this year to work over my VST and found the intake runners around the injectors were coated in gunk. also the back side of the valves were caked up some. i didnt do anything to clean it and recently ive been trying to resolve my slow to start issues and rough idle. i have replaced many parts and tested everything else i could think of. the problem stayed the same until recently when i had the VST off again i cleaned out the intake while it was off. carb cleaner took the gunk off pretty quick. i decided to do the inside of the head that i could get to too. same thing, carb cleaner took most of it off except for some of the junk on the valve stem. after cleaning it some now the motor is consistently starting easier. not perfect but its a improvement. i also looked in the cyl when i had the spark plug out, the piston looked black with carbon. im now thinking the motor is just needing a serious decarb. the previous/original owner only used regular pump ethanol and the boat routinely had junk fuel in it. im not sure if this buildup is a result of his crap gas or a problem with too much fuel. i emptied the gas tank when i got the boat and have exclusively ran non ethanol fuel.







that was a clean bottle, i dumped the contents of the fuel filter in it and tapped it some, all that dip-spit looking crap came out.


ethanol dried out fuel pump diaphragm.

 

[clanton]

Sea Foam or BRP engine tuner will clean the gunk off of the valves, some in fuel tank, some sprayed into intake with engine running. The lap top with program and oxygen sensor will reset the computer if too rich or lean. A Suzuki manual very helpful.

 

[tjl76evinrude]

I have had good luck with seafoam before, I got some quickleen to try also. I have a factory manual and the SDS software. The 02 sensor won't do me much good right now even if I had it, the plug for sensor is corroded up and froze.

 

[tjl76evinrude]

used seafoam deep creep today. pulled the spark plugs and injectors so i could get to the cyl and intake valves directly. i turned the motor over by hand until each valve opened then hosed the deep creep in. let it sit for a while and kept turning it over by hand. let the starter run it with the plugs out then put it back together and fired up. decent little smoke show, still ran about the same. noticing more it seems like water is not making it up to the thermostat very easy.suspected the relief valve might be bad so i decided to pull it. didnt seem to be in terrible shape. i did find my spark plugs odd. the top cyl plug is clean from i guess burning hotter and the lower 2 are fouled up. these plugs only have a few hours run time on them. maybe 6 hours tops.

 

[tjl76evinrude]

so now that i look, apparently deep creep wasnt the right stuff. i thought it was just seafoam in a spray can but apparently its just a lubricant. guess i'll be repeating the process with real seafoam.

 

[tjl76evinrude]

Parts took extra long to get in. Should be in tomorrow. Hopefully Sunday I can get it back together, de carb it for real this time and hopefully get it running right.