900 dies-out at speed

I went to Leesburg BikeFest yesterday, met with my friend who has a ZZR1200 and rode 130 miles in the country on a +perfect+ 75* day.
The Kawasaki will do 110 in SECOND gear, @11,000 RPM ! We get on the Interstate, light traffic, and maintain 100 MPH.

After about 5 minutes my motor starts "going away" and I fall back and move to the right, then for a bit I had almost nothing, like a battery went dead. (replaced fuse box) I'm going 70, 60, I'm trying various throttle positions, traffic is looming in my mirrors, back about 1/4 mile. I threw some "choke" at it, throttle closed, 50 MPH felt like I was riding a moped.

Didn't want to stop - my friend never noticed me falling out - and with a semi gaining, I jump to the shoulder at 40 and focused on watching for debris as I babied the throttle on my 3 Horsepower Seca.

After what seemed like forever (2 minutes on the shoulder!) the motor felt strong enough to join traffic at 65 and when I took the exit in a few miles the bike had full power and idling perfect. This all happened at mile 70 of my day after getting a full tank of Marathon 87 Octane, the bike cold started perfectly this morning.

more info - my bike's thread

I didn't do my spring tune-up yet, which starts with the valve lash check - you know procrastination takes dedication :wink: Ideas?? Valves evenly out of adjustment? It would take alot of water in the gas to cause this, as the bike was on "ON". Overheated?? It's the longest I spent at that speed.

 

I'd say that if your bike slowly lost power, then after riding slowly, regained power, that you're bowls weren't being filled as fast as you were burning gas going 100 mph+, then when you babied it, they got a chance to refill.

I'd suspect the petcock, vacuum hose that actuates the pecock in ON collapsed or came off, or some kind of blockage that's pinching off the fuel flow (air bubble in the fuel filter, old, clogged filter).

 

Dirty gas, water/moisture in gas.

 

I have been having this EXACT problem lately. Never 2 whole minutes, but maybe you have bigger bowls or slightly different config.

I strongly suspect it's the petcock. It sounds to me like gas isn't getting to the bowls. Moving it to prime has helped in the past, but I think my seals are just going bad. I've even started running it on prime usually lately, but even had it do the routine on prime the other day. Pulled over to the shoulder, dropping gears, letting off the throttle, babying, finally dies in first. Pause for just a second and let it sit. Move the petcock to 'ON' and back. Bam. Starts right up as if there never was a problem, gets back on the highway, no more problems for the rest of the 50 miles I rode that day.

I'll let you know if my petcock rebuild fixes it, but it's hard to say, as it's a very intermittent problem. I had this issue and started a thread a week or two ago, had it three times in two days, then two weeks with no problems.

Let me know if you find anything, i'll be watching this thread closely, since it just happened again last night. It's dangerous, if this happened while overtaking someone it could be a really bad day. Driving really cautiously at the moment, staying close to shoulders.

 

There you go people, even XJ guru's and wizards need help occasionally, anyway, on to your problem Time, it sounds very much like the others may be on the right path, as to me also, it sounds like fuel starvation of some kind, Shite in the carbs? (that was a question by the way, not a cure) or the tank? Maybe the vacuum hose collapsing?

It could have been caused be over heating at the same time, the insufficient fuel supply to the carbs, evaporating I suppose. Though I'd be suprised, as these bikes can cruise all day at 100mph, so I'm led to believe.

What about coils, have you touched them at all, as in disconnecting the power leads to them? I ask that coz maybe when they were reconnected, one of the connecters wasn't/isn't making contact properly.

Just throwing some suggestions for you.

Pete

 

Thanks for the ideas, and keep'em coming -

I can't work on it 'till Sunday, it'll be easy to check a fuel-flow - fuel quality problem. Ignition coils overheating would be hard to re-test, but I'm thinking something got hot, then cooled off.

Maybe my Horse got tired and needed a breather - it STILL never left me walking !

 

Mmm coils overheating, had not crossed my mind at all, and like you say, that IS going to be hard to get to happen again.

Just re read your first post again, and believe it or not, it wouldn't take that much water in your fuel to create the problems you described. quite a few years ago, i had exactly the same problem, but in a car, not a bike.

I drained the tank, fuell lines, and finally the carbs, it all contained in total less than around 4 fluid ounces (American) of water - yes, you guessed it, in the carbs, less than a cup full in total, whilst driving Normally, petrol was getting into the carbs and the engine ran ok, but boot it, and of course, it started to do your description, as fuel wasn't filling the bowls quick enough, so it started to drag the water.

 

You had 4 ounces of AMERICAN water in your carbs and tank!?!?!?!?!

Dave F

 

Sounds like what happens when I need to switch to reserve. Fuel starvation.

Doesn't sound like something blocking the petcock filter, but I did have this happen once on my CB750 when the inline filter got clogged.

Could possibly be a vac line issue. Older vac lines can collapse when they get hot, but I've not known one to cool off to the point of working correctly again.

Good luck on getting it sorted

 

Nice one Dave, I asked for that, No it was definitely english water, I wasn't sure if the fluid ounces was the same amount both in the US and UK, as most if not all other fluid weights etc are different, as in, your pint is 16 fluid ounces, here in the UK it's 20 fluid ounces,there's US gallon and imperial gallon. Which should mean, but I can't be certain, that our litres are different sizes too. Maybe one of you can clarify?

 

I thought "a Pint's a Pound, the World around" was a British saying ?
Liters are the same (regardless of spelling)

 

Time, before you dig into all of that. Remove the gas cap and take it apart and make sure it's clean and the vent is not plugged with dried gas or that white aluminum corrosion fuzz. A clogged gas cap vent will starve your engine for fuel.

 

Good point, that one slipped by me, completely forgot about that

 

I just moved the bike and heard the "hiss" of vapor escaping from the cap pretty quickly, It doesn't clog in just one direction, right??
Both the cap and inside of tank are near perfect condition.

I siphoned both low corners of the tank, found some odd grey dirt-sediment, no trace of water. Flow-test is next, which will also test the vent.

Has anyone ever bothered to measure how much fuel flows in 60 seconds??
That would be a handy bit of info. . .

 

Just remove the cap and pull it apart and clean the check ball and the hole it sits in. Won't take you ,ore than 15 minute. That will eliminate the cap vent system. And yes it can restrict air going into the tank if crud is in the check ball well.

 

The motor's not partially seizing is it?

 

TtR - I had nearly the exact same problem on my 750 and it was the petcock. I would be fine at lower speeds but when I ran at a sustained duration at highway speeds it would start to lose power just as you described (just like when you are nearing the point when you need to switch to reserve). Pretty simple solution and if you order today I'll bet Len will have you the petcock by Saturday.