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Discussion Starter #1
My '97 just refuses to run properly. Ever since I returned from my second tour it has run terribly. It sat a total of one and a half years without being started while I was away. I am guessing it has something to do with electrical because of the maintenance I have done since. First I ran some good fuel system cleaner in it with no change. Took off the carbs and cleaned them thoroughly, no change. Changed the spark plugs, no change. Sync'd the carbs, no change.
Here's the symptoms:
-only runs with the choke on
-hesitation throughout RPM range (even when letting off)
-barely burns the fuel, strong smell of fuel


So what's the ideas? I'm thinking my coils are shot? Bike has about 20,000 miles on it.

And is this the right place to post this?
 

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Good choice of bikes. The FZR 600 does everything pretty well, and not much poorly.

The clue is in your post: You say it only runs with the choke on, and smells strongly of fuel. Get the carbs cleaned/rebuilt. It's a nine year old machine, and if it's sat for a while, you may have something gummed or clogged.

If you haven't already done so, consider having a jet kit installed. I'd recommend stage one, as the airbox does help out the midrange on the FZRs. While they are installing that, they should be looking through the carbs to ensure they are clean and unclogged.

Hope this helps.
 

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Discussion Starter #4
I tore the carbs apart and cleaned them out good, the bowls were suprisingly clean, so I don't think that was the cause. Any further ideas?
It also did went from running great last fall, to running terribly 7 months later, why I think it is electrical. I did change the battery 2 months ago also.
 

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take the plugs out, one at a time, put the cable on, and touch them against the block. Turn the starter over and see if the plugs fire. If the do, its not electrical, and you probably need to mess with the carbs some more. If they dont, start by going after the coils...
 

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And after you get the mice out of the air cleaner have the battery checked.
They only have a short life anyway and yours wasn't on a battery tender. Probably needs to be replaced.....
No reason for the coils to be shot.
 

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Discussion Starter #8
The battery was shot and replaced 2 months ago. As for the air filter, it is dirty but the bike runs the same with the airbox on or off. Still have check all the plugs for spark, but cyl. 1 and 4 get spark so far.
 

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I was going to say give it a winter rest but your in SO CAL and probably want to smoke some canyons...

I'm stumped,,,but a good mechanic could probably sort it out in no time.

Be wary of shops that just want to sell you new PARTS...

Good luck...
 

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All things being equal, the choke being on just enrichens the fuel in your idle mixture. If it is running on it's own with the choke on, but not off, there is something not right in one of the other circuits in your carburation. My guess would be the pilot circuit, but the affects are accumulative.

Try reading this. Pretty good information about how carbs work. This is a better explanation.
 

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Dan's posts makes me wonder. Could there be a leak in the intake between the carb and the head?
 

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Vash said:
Dan's posts makes me wonder. Could there be a leak in the intake between the carb and the head?
That is entirely possible. Could spray carb cleaner on the boots and see if the idle changes.
 

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Discussion Starter #13
Ok did some more work on it with some advise and heres what I came up with. I took off and checked the exhaust to see if it was clogged, and it wasn't. Checked all the plugs for spark and they all had spark. I put it all back together and fired it up to see if a cylinder was missing by spraying water on the exhaust. #4 was the only cylinder that did not boil water off instantly so I guess #4 is the problem. Could a bad CDI cause 1 cylinder to miss? Coil? I think the coils give spark to 2 cylinders so wouldn't both of them be bad?
 

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CDI and Coils only control the spark, if all plugs are firing, that your problem is fuel, not spark.

Check in intake manifold leaks, carb problems, and compression...
 

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Vash said:
CDI and Coils only control the spark, if all plugs are firing, that your problem is fuel, not spark.

Check in intake manifold leaks, carb problems, and compression...
:cheers:

I need the popcorn smiley, because all I'm doing now is sitting back enjoying this Vash.

I'd recommend he ride it at 30% or greater throttle and shut the choke, then see if it loses power. If so, I'd guess the pilots are running lean.
 

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you are giving me too much credit dan. Engines are all well and good, but once people start talking about the insides of carbs, I'm lost. I mean, how do they fit a jet and a pilot inside one of those? And how do they feed the pilot? Amazing things they are doing with technology nowdays....
 

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DanQ said:
:cheers:

I need the popcorn smiley
you got beer and you're asking for popcorn? Whats wrong with you man?
 

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Take a set of aligator clips and trace your spark back. Seems like you know what ur doing, but I kind of got lost in your description, did you say that only plugs 1 and 4 are firing? If so, take your clips and go backwards from 2-3, Not sure on an FZR how the config is, I know there are only 2 coilpacks with a rotor-type dealie to fire them. See if you're getting spark immediately from the coil (pre-wires). Check the continuity through the coil compared to the other coil..

Also, check for leaks in your plenum (intake manifold) with propane (dangerous, I know, but it works). That would cause the wierd stuttering at inconsistant intervals. Other than that, I'd start with sensors... Does it run any different hot than cold? If it runs wierd cold but not hot, 90% says It's coolant temp sensor (IDK if bikes even have these, I'm a car mechanic).

[/prettygenericadvice]

~Laura.
 

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Laura: A pro mechanic could be a great deal of help here. From what I understand of the guys posts, all plugs are sparking, but the #4cyl isnt firing.

FZR: Did I understand you correctly. All spark plugs are firing, not just capable of firing, right?
 
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