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Discussion Starter · #1 ·
Bought cbr 929, changed plugs cause she would not fire up. Now, she fires up, but idles rough, around 1300rpms, then idles low, lights dem, flicker low then high, and she dies out if I dont hit throttle. Just put 2 qts of oil in her, cause she was real low. When I took her around the block, she seems real jerky when I hit the throttle or let off. If I dont stay on the throttle she will bogg down and die while coasting. Any ideas what I can do, or did do wrong? Thanks in advance. She might be up for sale soon if issues persist.
 

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Ace Tuner
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3,489 Posts
You did not say if the bike been sitting up for any length of time. Has it?
Here are some guesses anyway.

Probably a fuel system problem:
Bad (old) gas.
Plugged fuel injectors.
Trash in the fuel pump/lines/fuel rail.
Bad fuel pressure regulator.
Massive air leak at the throttle body / intake manifold joints....

S F
 

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Discussion Starter · #3 ·
The bike sat for winter. The guy I bought it from said it was the first winter he's had it, so there wasn't a ton of information given on it. I emptied the tank and filled her up before starting her, but nvr empties the lines. I'm not mechanically inclined for all that, I'm guessing my best bet is to send her to the shop at this point. I noticed she didnt have any oil in her so I put 2 qts in it. Noticed my fan isn't kicking on so I went and got the toggle and wires to hotwire it this evening. But I believe I'm just gonna find a good bike mechanic and have them check her out. Any tips on how to check those things? Besides the fpr idk how to check the other things.
 

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Ace Tuner
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Even though the bike has a "cooling" fan, the bike relies on forward movement so enough air can flow thru the radiator to cool the engine... It does not work like an automobile.
The fan will not come on until the bike is getting very close to overheating. The fan is sort of a last ditch effort when the bike is trying to get too hot. As a matter of fact, when the fan does come on it's time to get moving real soon or shut the bike off to avoid overheating. The fan alone does not have the ability to move enough air to cool the radiator/engine.
I wouldn't put a toggle in it just yet.

If the fuel you took out of it was kinda funky your fuel injectors are probably somewhat plugged with funky, old fuel that has thickened.
Cleaning the injectors is not really a job for a first timer. Taking it to a pro would probably be the best way to go from here.

Please let us know how it all shakes out so others might be able to benefit from what is ultimately learned about this one.
S F
 

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Retired twice: Navy and as a govt contractor
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You could run a heavy does of an injector cleaner like seafoam through it and see if that helps. If it does repeat it with the next tank. If not then perhaps a mechanic might be your best bet.
 

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I sense a lack of patience with a machine that has been neglected.
Me, I’d charge the battery up real good.
Clean out the entire fuel delivery system from tank to injectors.
Then see where it is.
But, that’s a lot of work.
A skilled mechanic or dealer is not cheap.
Before the situation at hand sours you on motorcycles altogether, I recommend you trade it in for something new, or just sell it.
Buy a used bike you can test ride, making sure it performs well, and enjoy riding.

My 2 cents.
 
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