Question about 2003 Yamaha YZF-R1

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Hi my r1 5pw is missfiring at low revs iv changed the plugs can u help its almost like a throttle position sensor as it idels fine untill u give it a little rev and it cuts out if u give it a big handfull its fine

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Hi, Tom and the usual suspects are:
1. Severely discharged or a damaged battery, should have 12.5 volts or better and be able to pass a load test if necessary.
2. Check battery terminals for damage or corrosion, check the battery cables at "BOTH" ends for loose, corroded, or broken connectors, "INSIDE" and outside the cable harness, perform connector wiggle test and check cables with an ohmmeter if necessary.
3. Spark plugs in bad condition or partially fouled.
4. Spark plug cables in bad condition and leaking check for spark leakage in the dark.
5. Spark plug gap too close or too wide.
6. Faulty ignition coil, module, and or sensor.
7. Loose, dirty, or corroded ignition module connector at crankcase.
8. Faulty CKP sensor.
9. Intake air leak.
10. Water, dirt, or rust in the fuel system, carburetor and/or filter.
11. Fuel tank vent system plugged or carburetor vent line closed off.
12. Vacuum line from intake manifold to fuel valve is broken, cracked, pinched, or missing.
13. Carburetor controls misadjusted.
14. Damaged carburetor.
15. Incorrect valve timing.
16. Weak or broken valve springs.
17. Damaged intake or exhaust valve.
18. Check for engine trouble codes
For more information about your issue and valuable "FREE" downloads that you will need please click on the links below. Good luck and have nice a day.
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Posted on Sep 02, 2016


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SOURCE: Wont rev past 3/8 throttle!! I NEED HELP.

could be. I had a 91 kx 250 that was acting crazy and it turned out to be the stator and cdi box. you can check the stator easly with a omes meter but the cdi box is nearly impossible to check. you pretty much have to buy a new one and try it. also check to see if your power valve is working.

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SOURCE: 02 Vmax Idels on choke will no idel or advance

you have a fuel delivery problem...have you tried a carb cleaner?  You may need to remove and rebuild the carbs.

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Usually related to TORS, specifically the safety switch in the clutch/park brake assembly. If it's defective the engine won't rev. Solution: look for a TORS removal kit.

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SOURCE: my 1999 R1 rev counter just shoots upto 7000 when on tickover

the exup valve is unpluged

Posted on Oct 09, 2009

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SOURCE: my 1999 r1 splutters a bit from set off to 4000

99 yzf r1 hit in back tire fell over and eversince makes a pinging noise when i release the clutch but when i pull it in it stops,the pinging noise sounds like its comming from the front maybe "carb" anyways theres no horsepower so i changed my plugs and oil still no fix can anyone tell me whats wrong with it

Posted on Nov 15, 2009

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