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Surging 1994 k75s

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New member
I'm hoping someone can help me out. I bought a 94 K75S sight unseen with low miles. 15,000. It started fine but when I started riding it, it threw a code and stated surging. The guy I bought it from had three new spark plugs and a new fuel filter in the side bag which is telling me he was going to have them changed. Do you think that will fix the problem or does anyone have any thoughts?
Feel like I need to change this lemon into lemon-aid. HELP!
 
There are dozens of things that could be wrong, but there are no codes to throw.

Gonna need more info. Where are you located? How long had the bike been sitting before you bought it? What does the fuel pump vibration damper look like? Is it soft? Is the inside of the tank discolored?

They didn't build any K75S lemons. Some people just didn't take care of some of them, leaving some of the 20 something year old K75Ss in need of some TLC! That's what you have.


:dance:dance:dance
 
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Unsure what code is being referred to, since the K75 uses an analog fuel controller..

One immediate thought it checking the Z shaped hose that vents the crankcase into the air-filter housing. Located right behind the coil area.. these die on a very regular 2-3 year schedule.
 
when I say a code I mean the red triangle light is on. Im in California the bike came from Michigan. when you say soft what do you mean on the fuel pump. the fuel pump vibration dampener? what do they run $$$$...Apx? would that involve taking off the tank? :clap
 
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when I say a code I mean the red triangle light is on. Im in California the bike came from Michigan. when you say soft what do you mean on the fuel pump. the fuel pump vibration dampener? what do they run $$$$...Apx? would that involve taking off the tank? :clap

Did the bike come with an owners manual? If so - it might be worthwhile spending a few minutes with it. The red triangle is a brake warning light. It illuminates if you have a brake or tail light out and/or if the bike has ABS and it hasn't initialized, or it's faulty. It has nothing to do with the engine.

The fuel pump is located inside the tank. It is suspended in a rubber mounting that unfortunately isn't happy with current formulations of gasoline, especially if left sitting in stale gasoline for a while. It pretty much melts into an awful looking, feeling, and smelling mess, and can get sucked into the fuel pump basically destroying the pump in the process.

I suspect that's the reason for that question.

The fuel filter is also located inside the tank, as are some high-pressure fuel-injection hoses, which have been known to leak inside the tank, causing too low fuel pressure which could also cause a lean condition and a surge feeling.

Lots to look at on an older bike where you have no idea of the service history..
 
Thanks. Unfortunately it did not come with a manual, I'm going start digging into it next week. thanks for your help.
 
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