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Two new (related?) problems have crept up in the last week or so. I thought perhaps it might be tainted fuel, so I removed the tank and completely drained the fuel, added Sea Foam, then refilled from a different gas station than my normal one, but the problem persists.

Ever since I bought the bike, when I start the bike cold, the idle RPM immediately settles at about a 2000 RPM, smooth as glass. Over the next 30 seconds or so, the RPM gradually slows and settles around 1400-1500 RPM. Beautiful. The last week, when I start the bike cold (60 - 75 degrees F ambient), it immediately sets into a very rough, low RPM idle, wavering between 1400-1600 RPM. It is a very hesitant, rough idle, accompanied by prominent knocking sound as the engine tries to find it's groove. I have to give it throttle before it will act normally, and the idle goes to 2000 RPM and everything is smooth and proper after that.

But lately it began doing something else. About ten minutes into a ride, around 25-30 MPH as I was moderately accelerating, the engine suddenly lost about half it's power. It was a very abrupt but smooth loss, and adding throttle eventually returned it to normal. Then it did it again a couple hours later between 45-50 MPH. No sputtering or lurching as might suggest bad fuel, just a sudden abrupt loss of about half power, enough of a loss to cause my body to lurch forward with the deceleration and catch me off guard and make my behind pucker. I did the fuel drain and refill thing, but the problem persists. Anybody else experience either of these things? Ideas?
 

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Have you pulled the plug?? The spark plug can tell you a lot about what's going on inside the engine(rich or lean conditions, oil consumption, detonation, etc..). Did you have the valves adjusted at the first service? You might have a valve out of spec causing a lean condition also. If it's under warranty I'd take it in to the shop.
 

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3 things to check,related to this.

1.air filter(first and second prblm)-if its dirty,replace it
(dont clean and use paper filterz)
2.spark plug(1st and 2nd problem)
-its hard to fail an iridium stock spark plug on this bike.but low quality fuel can cause it.
3.o2 sensor(for 1st problem) of varied idle.

Air filter costs-6usd here
o2 sensor-6-10usd
spark plug(iridium)-30usd
 

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Are you starting it before the tacho sweep finishes and fuel pump stops doin its thing?
 

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Yeah never heard of an O2 sensor for less than about $25-30 and that's an old two wire non-heated one. Most new 3 and 4 wire hetaed O2 sensors are $40-$100+.
 

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Erattic Engine Operation.

Two new (related?) problems have crept up in the last week or so.

The last week, when I start the bike cold (60 - 75 degrees F ambient), it immediately sets
into a very rough, low RPM idle, wavering between 1400-1600 RPM. It is a very hesitant,
rough idle, accompanied by prominent knocking sound as the engine tries to find it's
groove. I have to give it throttle before it will act normally, and the idle goes to 2000 RPM
and everything is smooth and proper after that.

About ten minutes into a ride, around 25-30 MPH as I was moderately accelerating, the
engine suddenly lost about half it's power. It was a very abrupt but smooth loss, and
adding throttle eventually returned it to normal.

Then it did it again a couple hours later between 45-50 MPH. No sputtering or lurching as
might suggest bad fuel, just a sudden abrupt loss of about half power, enough of a loss
to cause my body to lurch forward with the deceleration and catch me off guard

I did the fuel drain and refill thing, but the problems persists. Anybody else experience
either of these things? Ideas?
Turbo DV8,

I think your previous Thread/Post about your engine pinging has developed into something more Serious.

From your description of your current Complaints and your previous Complaint.

I suspect your cbr's engine has a Fuel Delivery System, that is not operating to design specifications.

Your previous complaint of engine pinging under normal operation, would be an indication of Low Fuel Delivery Pressure from the fuel pump assembly.

On the engine's rough and labored idle. Low fuel pressure would also cause these conditions. By you varing the throttle, your are also varing the TPS signal to the ECM. This will vary the injector pulse width, which will also cause a fluction in the fuel pressure, which will create shock waves in the liquid gasoline inside the fuel pump assembly which also incorporates the Fuel Pressure Regulator and the supply line to the fuel injector.

The power loss at 40-50 mph. Could also be a condition of low fuel pressure. With the sudden loss of correct fuel pressure, the smooth loss and smooth return to correct speed is also another indication of low fuel pressure.

Why the fuel system and not the ECM or Sensors?

This EFI System is a very Basic EFI System. It's only sets a code for an open or shorted Sensor. There was no Mention of a Malifunction Indicator Lamp being turned on.
.
 

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hey,checkd it.all other sensorz are cheap.o2 sensor is costly
than other sensors in the bike.
i cross checkd with my mechanic

PAJKRUBI AND YOU are right
Ie;
o2 sensor-60-100usd
spark plug-30usd
air filter-around 6usd

and ya TURBO,
the spark plug is already iridium.i knew this when i approached my mechanic to change mine to iridium.
He
told
''you paid a lot for this bike,and everything must be top quality''
 
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