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'96 900ss cutting out

2661 Views 21 Replies 8 Participants Last post by  2tallpaul
My bike has been cutting out whenever it wants, just losses power and dies. Usually, i can start right back up. Some times i wiggle the wires around to get it to start. It generally doesn't happen at idle, only when moving. Nothing related to acceleration, braking or cruising, just whenever. I thought it was fuel, but now I'm thinking electrical. This year, ive added CACycleworks coils, Ignitek ignition and Mikuni flat slides. It's just been one thing after another, but this time I'm stumped. I'm fearing a broken wire with intermittent connection. Any clues where I even start looking?
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Fuel tank vent line maybe? I've seen a plugged or kinked vent line cause the symptoms you describe. Once the vacuum that formed above the fuel as the level dropped dissipates, things will be normal until the vacuum is greater than the pump suction....if your pump is still working/fuel filter or pick up sock not plugged up.

An intermittent electrical issue is a possibility too....but then I don't think it would matter whether you were at idle or not, it would just randomly quit. All I got....sean
When mine did that it turned out to be a clogged fuel filter in the tank along with a completely rotted fuel pump "sock". Exactly those symptoms, wiggling any wires was a co-incidence as it was actually just the time interval necessary for the fuel to seep in via gravity to the float bowls.

It could easily idle for an hour or more, but once you get going it would starve for fuel most of the time. Aggravating, sometimes it would let me ride an hour away from home before acting up like this.
I forgot to mention I had found the in tank filter had split and the sock caked. Both were replaced. I also added a 'pill' into the return line to reduce the flow back to the tank. I will admit a very quick, sloppy tank clean out, which was very rusty. I have an inline one way valve on the tank vent, which seems to be working, but easily removed. I guess I'll continue chasing fuel issues. Thanks for a bit of direction adjustment.
My 96 would stall intermittently and start back up. Mine turned out to be the wiring to the regulator had worn through and was shorting on the frame. Assuming this might not be the only spot on an old bike that this was happening, I cut all the zip ties holding the wiring harness to the bike and examined all of it, fixing anything that looked shaky. No more stalling.
It looks like I'll be stripping the bike down, recleaning the fuel system and checking every electrical rub point. I do remember back in 2004 the soft forks allowed the fender to bang something (regulator?) and blow the main fuse. Gonna bite the bullet and just do it. Thanks for the input. I think this all started when I began to drool over the 959 Panigale Corse and the SS is expressing it's displeasure
Try rattling the key while the bike is running. Sometimes it is the ignition switch having intermittent contact.
It's going into the garage I can use 1 day a week and not coming out until i find something wrong. And then I'll look for more... The limited garage access is forcing me to fix one thing and call it good, until I find that isn't it. I'll post what I end up finding.
Could the fuel line running through the frame next to the rear cylinder be causing a problem? I've got both lines running side by side, but not touching the head. The fuel line wasn't original when I got it and I've never been sure of the proper routing.
Could the fuel line running through the frame next to the rear cylinder be causing a problem? I've got both lines running side by side, but not touching the head. The fuel line wasn't original when I got it and I've never been sure of the proper routing.
I would tend to think not, but then again, if there is a kink in it, that could restrict fuel flow...but also trap any particles that made it into the lines when you did the pump replacement.

Routing isn't super critical other than keeping the hoses away from heat and stuff that can rub through and cause a leak. Keeping fuel lines from kinking is fairly critical as is ensuring the line doesn't split at or near the hose clamps....but most of that is common sense.....sean
I've got a small gap below the frame crossbar between the head and belt cover. Or around the right side around the belt cover. Or the left side, which is more spacious, but runs just above the spark plug. I'll look again for a route between the frame and gas tank. The airbox is gone, so I have plenty of room once I get into that space and more tidying up to do. The fuel lines are all new, 1/4" id. I've got a new in-tank filter and pre filter ordered, as well as zip ties to re-secure all the wiring after going through it.
I think the topic was fairly bludgeoned to death in another recent thread, but the fuel hose size is 8mm, so 5/16 would be closer to what is needed.
Same puzzle here

Sounds like the exact same intermittent symptoms my '94 900cr exhibits.
Some days no problem all day, some days it will go 20-30 miles, then act like it's
running out of gas and dies. One day it did it on a 5 mile errand.
When it died last couple of times, I popped open the filler as soon as I stopped -
no start, no apparent venting issue. I could see fuel return dribbling back into the tank. Shut it off and wait a minute and it starts right up and continues on its merry way and runs strong.
Both cylinders shut down. No highway or local road or fast /slow pattern.
I am about to pull the pump & filter to check & replace the NEW filter. Already did new lines.
Had it apart last year and the sock appeared to be in good shape - now who knows?
I strongly suspect crap in the secret little filter screen in the carb/fuel hose connection tee.
Another possibility is dirt in the float bowls (both?, not convinced).
Sure doesn't feel like an electrical gremlin - it goes soft then dies completely.
Not sure what else I may be missing here.
I'll let you know if/when I find this one.
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I had a car that used to die everyday in the same spot, 1/4 mile after I got on the highway. Turned out to be a flake of paint in the float bowl that apparently covered the orifice when I floored it to get up to speed. I had a Buell that got water in the fuel every time it rained. Yea, I’d drain the float bowls. Some times you have eliminate things as a possibility.
I finally got around to replacing all the fuel lines with a larger size, put a small restrictor in the return line. Routing is kink-free and not touching the engine. The fuel tank got cleaned out and a new filter and pre-filter were installed. The bike fired up and sounded a bit crisper than before, probably due to fresh fuel. I started checking electrical connections and I got a phone call and had to put everything back together and get the bike out of my borrowed shop space. AAARRRRGGGGHHH story of my life. Test ride now planned this weekend.
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If you cleaned the tank out I am hoping you did it well--my suggestion would be to use the POR 15 tank sealing system--The tank on my 91 900ss had some rust in it from sitting for 18 years-but I would call what I had more superficial surface rust then anything, once I cleaned it per instructions I noticed no pitting -so I got lucky--but I cleaned and lined the tank and now all if well---I suggest if you are going to take the time to address an issue--then fix that issue properly--then move on-that way you dont have to go back and do it again because you 1/2 arsed it think --hummmm--maybe this will work-if not I'll do it again. Do the job correctly the first time then forget that as an issue
I used to use POR-15... and then
Well, I went a little crazy. Got rid of the CR forks and the lithium battery. I replaced the VR with a mosfet unit from Ricks.
One thing I did find, was the insulation on yellow wires going to the voltage regulator were a gooey mess underneath the black outer coating. Bare wires and insulation that looked like it was melted by chemicals went about 4-5 inches into the black housing.
Still don't know what was causing my sudden engine stops, but the melted wires certainly needed to be dealt with.
My regulator wiring was melted from shorting to the frame when I bought mine. It kept blowing a fuse until repaired.
Op-did it fix the problem?
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