20 Most Recent Pit Bike 125cc 4 Stroke Dirt Bike Questions & Answers


Hi, David 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.
https://www.motosport.com/blog/help-my-dirt-bike-wont-start
https://www.youtube.com/watch?v=4ifXLvkB0RU
http://www.partsforscooters.com/Dirt-Bikes-Parts/Dirt-Bikes-Repair-Manuals
https://www.orionpowersports.com/pit-bike-dirt-bike-parts
http://www.ssrmotorsports.com/store/ownersmanual/pitbike/Pit%20Bike%20Owner's%20Manual.pdf

Pit Bike 125cc 4... | Answered on Jun 06, 2019


Hi, Damon and the usual suspects are:
1. Dirty air filter.
2. Fuel mixture too rich or the choke has been left on too long.
3. Faulty spark plug.
4. Incorrect spark plug heat range for the engine type or service.
5. Piston rings badly worn or broken.
6. Valve guides are badly worn and/or seals worn, crushed or have come off the valve guide and are pumping oil through it.
7. Spark plug cable weak or leaking check for spark leakage in the dark.
8. Faulty ignition coil.
9. Low RPM nonaggressive riding style.
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.
Why Does My Dirt Bike Keep Fouling Spark Plugs
Spark Plugs Keep Fouling
http://mypitbike.ru/downloads/ThumpstarServiceManual.pdf
https://www.orionpowersports.com/pit-bike-dirt-bike-parts
http://www.ssrmotorsports.com/store/ownersmanual/pitbike/Pit%20Bike%20Owner's%20Manual.pdf

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

Pit Bike 125cc 4... | Answered on Feb 13, 2018


Hi it sounds to me that the teeth on the front chain sprket could be worn so the chain locks,best thing to do is to take the side caseing off and check.(if it needs replaceing its always best to replace the back sproket and chain aswell,wish you all the best.

Pit Bike 125cc 4... | Answered on Jan 25, 2018


Hi, Jack the answer to this question is way above my pay grade for this situation, I would call or visit 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 for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
stomp 125 clutch wont engage new clutch all think Pit Bike Club
Clutch Adjusting
Pit bike Direct User Manuals
http://mypitbike.ru/downloads/ThumpstarServiceManual.pdf
http://www.wpbracing.co.uk/engine-parts

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

Pit Bike 125cc 4... | Answered on Oct 09, 2017


Hi, Jose and the usual suspects are:
1. Wrong coil for service application.
2. Damaged or worn out spark plugs.
3. Spark plug gap too wide.
4. Damaged, leaking, worn out spark plug wires, boots, or center cap connectors check for spark leakage in the dark.
5. Excessive vibration due to the loose mounting bracket.
6. Faulty ground 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.
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.
Bad Stator Fix Don buy new stator for your engine Create battery op...
ELECTRONIC IGNITION
http://mypitbike.ru/downloads/ThumpstarServiceManual.pdf
http://www.miniriders.com/tech-talk/29110-pit-bike-repair-parts-manuals-exploded-views.html
http://mypitbike.ru/downloads/SSROwnersManual.pdf

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

Pit Bike 125cc 4... | Answered on Dec 14, 2016


tighten the chain and straighten the back tyre

Pit Bike 125cc 4... | Answered on Feb 04, 2015


is the bike a2 stroke or a four stroke? regards Ray.

Pit Bike 125cc 4... | Answered on Nov 25, 2014


you will have to check lead to spark plug then lead to coil
if your not getting spark at plug it could be a number of things ingintion
or just a loose wire best of luck hope you solve it

Pit Bike 125cc 4... | Answered on Nov 17, 2014


use a slide hammer with bearing attachment to pull out old bearings
and replace with new ones

Pit Bike 125cc 4... | Answered on Aug 24, 2014


You can check ur values but some bike do make a we ticking from the values and it will back fire when revved up because of the extra fuel once revved that hasn't brine burn as it revs back down to idle speed.

Pit Bike 125cc 4... | Answered on Jul 26, 2014


Clean carb and air
mix screw needs set and rev screw

Pit Bike 125cc 4... | Answered on Jul 26, 2014


Check the wiring on the connector plugs make sure all the wires are the same color on both sides, red to red blue to blue and so on. I had the same problem After replacing a stator and just plugging it in,after two weeks a new cdi and coil i noticed there were two wires transposed.

Pit Bike 125cc 4... | Answered on Jul 19, 2014


when you put a bike into gear the chain tightens sounds like it is to tight move the back wheel closer to the swing arm about an inch that should do it

hope this helps

John

Pit Bike 125cc 4... | Answered on Jul 19, 2014


If youre talking about the spring in the carbs. throttle bodythe answer is yes.
Inside the main chamber is a cylinder with a long pin ,this pin or needle goes to the main jet which governs the gas flow.
if the spring is missing the needle will be in the wrong position .
as far as the floats are concerned they teater on a set pin and are designed to float on top of the fuel in the float chamber.make sure they move freely and that there not rubbing on anything or bent.you might want to try some starting fluid to get things started then make your adjustments,after starting aduust the idle screw first.
a good formula for idle screw is turn the screw all the way in .
Then turn it out 3 and one half turns out,
good luck,Gary

Pit Bike 125cc 4... | Answered on Jul 19, 2014


It's a grounding problem

Pit Bike 125cc 4... | Answered on Jul 19, 2014

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