Question about Yamaha Motorcycles
Engine running badly
Posted by Anonymous on
Hi, Anonymous 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 or CMP, MAP, ETS, ATS, TPS, O2 sensor.
9. Dirty air filter.
10. Intake air leak.
11. Water, dirt, or rust in the fuel system.
12. Carburetor damaged, contaminated, sticky float, plugged jets.
13. Fuel filter clogged.
14. Old or contaminated fuel.
15. Fuel tank vent system plugged or carb vent line closed off.
16. Gas cap diaphragm valve faulty.
17. Vacuum line from intake manifold to fuel valve is broken, cracked, pinched, or missing.
18. Carburetor controls misadjusted.
19. Incorrect valve timing.
20. Valve springs floating, weak, or broken.
21. Damaged intake or exhaust valve.
22. Incompatible performance parts.
23. 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.
Yamaha Carb Tuning
OEM parts for Yamaha
Posted on Feb 03, 2017
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Posted on Jan 02, 2017
SOURCE: regarding the fuel stopcock of
You have a vacuum operated petcock....so that when engine starts and draws vacuum...a diaphragm lifts in the petcock to supply fuel to carb. When the engine shuts off...vacuum is lost and the petcock closes.
If you run the tank empty....in order to get fuel into the carb and get the bike started initially....you can open the petcock without engine vacuum by rotating petcock to the PRIME position. Once started return the petcock to the ON position. If you leave it on prime....with engine off...fuel may leak into carb and run into engine and contaminate crankcase oil with fuel.
Posted on Mar 23, 2011
SOURCE: yamaha tt-r 225 backfires, no
You carb needs to be removed, completley disassembled, and soaked in a quality carb cleaning solution, overnight. The bad fuel has gummed up your carbs internal passageways
Posted on May 13, 2011
Testimonial: "already started, thanks"
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