20 Most Recent 2005 Yamaha yZ 125 Questions & Answers


Hi, Nichlaas and the usual suspects are:
1. Fuel tank empty.
2. The fuel tank has old dead gas.
3. Fuel tank bottom contaminated with ethanol sludge, dirt, water, rust, etc.
4. Fuel supply valve/petcock turned off.
5. Fouled spark plugs.
6. Engine flooded as a result of overuse of the choke.
7. Vacuum hose to the fuel supply valve/petcock disconnected, broken, cracked, or pinched.
8. Fuel valve/petcock or filter clogged.
9. Fuel line to carburetor or throttle body pinched, kinked or blocked.
10. Carburetor float stuck.
11. Fuel injectors clogged.
12. Fuel injectors stuck open.
13. Quick disconnect check ball stuck.
14. Compression below 75 PSI.
15. A stuck-bent-burnt valve.
16. Improper valve clearance (too tight)
17. Severely discharged or a damaged battery should have 12.5 volts or more and be able to pass a proper "LOAD" test if necessary, you may have a cursory reading of 12.5 volts or more but little or zero amperage the battery is faulty and must be replaced, AGM batteries fail in this scenario more so than lead-acid batteries.
18. 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.
19. Loose or corroded wire connection at the coil or plug between ignition sensor and ECM module.
20. Spark plug cables in bad condition and shorting check for spark leakage in the dark, cable connections are loose or connected to the wrong cylinders.
21. Ignition timing incorrect due to a faulty ignition coil, ignition module or MAP, CMP, CKP, O2, TPS, ETP, IAC sensors.
22. Faulty neutral, clutch, kickstand safety switch.
23. Faulty fuel pump or fuse or relay.
24. Faulty or corroded run/stop switch.
25. Tilt sensor needs a reset.
26. Security system not disarming alarm needs a reset.
27. Check for engine trouble codes.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
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YAMAHA YZ125 Owner Service Manual
https://www.partsfish.com/page/oem-parts-for-yamaha
http://mybikemanuals.com/yamaha/yamaha-yz-owners-manuals

2005 Yamaha yZ... | Answered on Aug 13, 2018


Hi, James your timing is too far advanced otherwise the usual suspects are:
1. Fuel tank empty.
2. The fuel tank has old dead gas.
3. Fuel tank bottom contaminated with ethanol sludge, dirt, water, rust, etc.
4. Fuel supply valve/petcock turned off.
5. Fouled spark plugs.
6. Engine flooded as a result of overuse of the choke.
7. Vacuum hose to the fuel supply valve/petcock disconnected, broken, cracked, or pinched.
8. Fuel valve/petcock or filter clogged.
9. Fuel line to carburetor or throttle body pinched, kinked or blocked.
10. Carburetor float stuck.
11. Fuel injectors clogged.
12. Fuel injectors stuck open.
13. Severely discharged or a damaged battery should have 12.5 volts or more and be able to pass a proper "LOAD" test if necessary, you may have a cursory reading of 12.5 volts or more but little or zero amperage the battery is faulty and must be replaced, AGM batteries fail in this scenario more so than lead-acid batteries.
14. 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.
15. Loose or corroded wire connection at the coil or plug between ignition sensor and ECM module.
16. Spark plug cables in bad condition and shorting check for spark leakage in the dark, cable connections loose, or connected to the wrong cylinders.
17. Ignition timing incorrect due to a faulty ignition coil, ignition module or MAP, CMP, CKP, O2, TPS, ETP, IAC sensors.
18. Faulty neutral, clutch, kickstand safety switch.
19. Faulty fuel pump or fuse or relay.
20. A stuck bent or burnt valve.
21. Tilt sensor needs a reset.
22. Security system not disarming alarm needs a reset.
23. Check for engine trouble codes.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
yz 125 wont start
2005 Yz125 Not Starting
YAMAHA YZ125 Owner Service Manual
https://www.partsfish.com/page/oem-parts-for-yamaha
http://mybikemanuals.com/yamaha/yamaha-yz-owners-manuals

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

2005 Yamaha yZ... | Answered on Nov 25, 2017


Hi, Anonymous for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere zero $ you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
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Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

2005 Yamaha yZ... | Answered on Feb 28, 2017


Hi, Tmillz44 for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere $0 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please click on the links below. Good luck and have a nice day.
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Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

2005 Yamaha yZ... | Answered on Jul 19, 2016


Hi, Kdcrayton for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere $0 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please click on the links below. Good luck and have a nice day.
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Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

2005 Yamaha yZ... | Answered on Jul 19, 2016


Hi, Moto582 for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere $0 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please click on the links below. Good luck and have a nice day.
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Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e


2005 Yamaha yZ... | Answered on Jul 18, 2016


Hi, Jacobhibbele for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere $0 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please click on the links below. Good luck and have a nice day.
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2005 Yamaha yZ... | Answered on Jul 18, 2016


Hi, Anonymous for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere $0 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please click on the links below. Good luck and have a nice day.
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Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

2005 Yamaha yZ... | Answered on Jul 18, 2016


Hi, Anonymous for this situation I would call my local dealer or reputable shop's service/parts department and inquire about any possible quick fix, answers, or parts inquiry. For more information about your issue and valuable "FREE" downloads that you will need please click on the links below. Good luck and have a nice day.
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Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

2005 Yamaha yZ... | Answered on Jul 16, 2016


Hi, Anonymous after careful deliberation 4 out 5 Yamaha Gods give this one a thumbs up, but just to be on the safe side you should give your local dealer's parts/service department a call to confirm. For more information about your question and valuable "FREE" downloads that you will need please click on the links below. Good luck and have a nice day.
Yamaha YZ125N1 Service Manual
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2005 Yamaha yZ... | Answered on Jul 14, 2016


Ii sounds like your bike cuts out when it get`s hot ? If it does this like clockwork then i guess you have same problem as me with my no limit 125 which does exactly that. i have fixed all connectors & cdi but it still does it. Which leads me to believe some ferrite core in the ignition system is going non-magnetic (called the Currie temp) at this "hot" temperature. It can either be the magnets in the flywheel or the core of ignition coil.I only use this bike for trips less than 10km so i live with it. if anybody can shed more lite plz!

2005 Yamaha yZ... | Answered on Aug 05, 2013


Yes you can make any wheels fit, but you may need to make spacers or fit new forks. I would suggest that you measure them both and see if they are the same size ( the brake fitment and the width of the axle bearing area may be different) good luck.

2005 Yamaha yZ... | Answered on Mar 14, 2012


Hi, John for this scenario you will need your service manual that has all fastener torque specs and a wiring diagram on the back pages, parts fiche, and owners manual if you can't find the best tool you ever bought for your Yamaha, despair not, for a mere $10 you can download another one.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
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Yamaha YZ 125... | Answered on Sep 02, 2018


I am not a expert so asker beware, but it might be that the clutch pads might be worn out or the pressure plate might be a little loose

Yamaha YZ 125... | Answered on Oct 27, 2017


Hi, Mark for this scenario you will need your service, parts fiche, and owners manual if you can't find the best tool you ever bought for your Yamaha, despair not, for a mere $37 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
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Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Yamaha YZ 125... | Answered on Oct 26, 2017


Hi, Anonymous for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere zero $ you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please click on the links below. Good luck and have a nice day.
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Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e


Yamaha YZ 125... | Answered on Apr 13, 2017


Hi, Chad and the usual suspects are:
1. Fuel cap or fuel tank is not venting properly.
2. Fuel filter clogged.
3. Fuel line pinched or kinked.
4. Float needle and seat sticking.
5. Float level too low.
6. Carburetor bowl vent line clogged/blocked/pinched.
7. Idle adjusting screw set too low.
8. Air/fuel mixture screw set too lean.
9. Idle port, transfer ports, slow air jet clogged.
10. Slow fuel jet clogged.
11. Faulty fuel pump.
For more information about your issue and valuable "Free" downloads that you will need please Click on blue links below. Good luck and have a wonderful day.
Bike dies when you give it throttle
YZ125 starts then dies after day of running fine
Yamaha YZ125T1 Owner Service Manual
OEM parts for Yamaha
http://mybikemanuals.com/yamaha/yamaha-yz-owners-manuals

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Yamaha YZ 125... | Answered on Feb 23, 2017


Hi, Anonymous for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere zero $0 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
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Yamaha YZ125T1 Owner Service Manual
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http://mybikemanuals.com/yamaha/yamaha-yz-owners-manuals

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Yamaha YZ 125... | Answered on Feb 19, 2017

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