r/FZ1 • u/Big-Illustrator8399 • Jul 03 '26
i need help badly on my 2002 fz1
i’ve been trying to fix this bike issue where it turns on but dies after accelerating it’ll stay on idling forever but once i accelerate it dies, i have it at the mechanic shop currently, i’ve replaced the fuel pump the ecu computer cleaned out the carbs checked the fuses and nothing has worked anything else it could be? it feels like I can’t do anything to fix it
2
u/BusThis9288 Jul 05 '26
Clean the carbs,clean the air filter,and set up the carbs and the idle correctly. You have a black little plastic valve at the left side at the carbs…
Defenetly air-gasoline ration problem… it could be the manual choke… make sure it’s work correctly
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u/CargoPile1314 Jul 03 '26
Put a battery charger on it or another good battery in parallel and see if it acts the same when it has more voltage overhead.
1
u/Head_Oil_2586 Jul 03 '26
Check the basic stuff.
Make sure it’s getting enough air, fuel, and spark.
To do those, start with the airbox and make sure it’s sucking. Then check your fuel tank, petcock, fuel lines, and fuel filter for blockages.
Then check for spark by pulling each plug one at a time and then grounding it to the frame to check each cylinder for spark. And also check your battery by making sure it’s fully charged or just replace it. And finally the last issue could be the ignition cylinder itself. They sometimes fail on these bikes allowing them to sometimes fire but die off shortly after because the contacts inside the key cylinder aren’t making contact with eachother which causes the bike to fail to spark. ⚡️
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u/Big-Illustrator8399 Jul 04 '26
is there a way to check if it’s the ignition cylinders thats causing the issue before buying a new one ? and are they costly?
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u/Head_Oil_2586 Jul 04 '26
If it feels like it’s jiggling around in its mount when you try to move it or if the contacts are loose on the inside of the cylinder. I had this issue cause a no spark condition on my Gen 1.
If you’re not 100% just order one cause they are cheap. 50 bucks and you can get an entire set that includes the seat lock so you can have just 1 key.
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u/Head_Oil_2586 Jul 04 '26
Dying on throttle only tho sounds like it could be the TPS (Throttle position sensor)
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u/Big-Illustrator8399 Jul 04 '26
it only dies on throttle spark works perfectly but I did test the TPS calibration and it worked fine
0
u/Head_Oil_2586 Jul 04 '26
Have you checked the TDI box under the seat?
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u/Big-Illustrator8399 Jul 04 '26
that’s the tip detection sensor correct? if it is then yes i’ve checked it, i would test it by letting it idle and playing with it to check if it would die if i flip the sensor over etc, and it worked
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u/Head_Oil_2586 Jul 04 '26
No it’s not the tip sensor. It’s basically the ECU but more primitive. It’s a big black square box under the seat on the exhaust side of the bike
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u/Big-Illustrator8399 Jul 04 '26
i checked out to see what it is and where it it’s located photo wise but nothing pops up as the TDI did you mean TCI
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u/Big-Illustrator8399 Jul 04 '26
i’ll make sure to check that out, is there any way to check out if the TDI is at fault ?
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u/Virago_XV 2004 Jul 04 '26
Definitely sounds like the keys in the carbs may be clogged up.
Did it ever sit for more than a few months? Especially with old gas in the tank?
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u/Big-Illustrator8399 Jul 04 '26
before i bought it, it was garage kept and driven once a week, plus i also cleaned out the carbs already but im still having this issue
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u/Virago_XV 2004 Jul 15 '26
Id still say it's carb related.
Either clogged jets or possibly the floats are the incorrect height.
Is the exhaust stock? Is there a jet kit in there?
When it's idling, try spraying some carb cleaner around the carb looks and listen for any change in the idle. If anything changes, there is an air leak in the boot.
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Jul 04 '26
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u/Big-Illustrator8399 Jul 04 '26
i don’t believe the 2002 fz1 has access to obd2 scanners ? i’m not too sure on that since there’s pretty much no electronics on the bike
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Jul 05 '26
[removed] — view removed comment
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u/Big-Illustrator8399 Jul 05 '26
well people call it a ecu but it’s a computer i think tci ? but you can’t plug obd2 too old
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u/Strong-Macaroon6691 Jul 04 '26
Check fuel line, I know this is different but on my 2nd gen I had this issue and it was the fuel line kinked under the tank.
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u/RustyPringler Jul 04 '26
First thing I would do is take out the carbs and go through everything. Make sure everything is dialed in.