20 Most Recent 2002 Yamaha YZF-R7 OWO2 Questions & Answers


Hi and welcome to FixYa,

To my understanding, most of these China made scooters uses a vacuum controlled cut-off fuel valve. Vacuum is tapped either from the carb out or intake coupler to activate and allow fuel flow; no vacuum no fuel from tank. Possibilities are:
  • no or little vacuum to allow fuel flow;
  • vacuum controlled cut-off fuel valve faulty.
A workaround is to install a manual cut-off or bypass it entirely.

Incidentally, the 'revs like mad' is a result of slight overflow when fuel first flows to a starved/empty carb bowl.

Good luck and thank you for using FixYa.

2002 Yamaha... | Answered on Mar 04, 2013


1. check if gaz flows from tank with the hose off.
if not then vacum operated on/off/reserve valve defective or not getting vaccum

ps check with gaz filler cap off, the vent may be blocked. the tank needs to pull in air to replace fuel volume, so it can flow

2002 Yamaha... | Answered on Jul 19, 2009


is it fuel injected if not try to adjust your air screw it will be brass flat head screw on out side of carbs

2002 Yamaha... | Answered on Jun 23, 2009


1.turn the petcock off at the bottom of the gas tank.
2.get something to put the gas in so you can see if its dirty or not.
3.take the hose off be careful not to splash the gas on you or in your eyes.
4.drain all of the gas.
5.if there is stuff in the bottom of the tank you need to take the tank off and rinse it with gas and get it all out.
6.in reverse put it all back together then put new gas in it then go over it and make sure its all back together correct then take off

2002 Yamaha... | Answered on Jun 06, 2009


23 l (6.1 gallon US)

2002 Yamaha... | Answered on Nov 10, 2008


Yamaha used a starter switch with 2 sets of contacts on many models.
One set opens to shut off the headlight (conserving battery power for cranking) the other closes to energize starter motor.
Problem is the switch gets sticky....so releasing it stops starter, but the headlight doesn't come back on after startiing.
key off, spray some WD40 around the button to get it inside, and work the button in and out...slide your thumb off to let it snap out.
Retry with key on to see if headlight now returns after cranking.

Yamaha YZF-R7... | Answered on May 05, 2011


carb inlet needles are leaking... change your oil before you run it again

Yamaha... | Answered on Nov 19, 2020


Yamaha would be a possible source.

Yamaha... | Answered on Nov 15, 2020


Try the basics first. When was it given a Full service? (Spark plugs, air/oil/fuel filters and oil change. Have you got any warning lights on the dash? Has it been standing unused for a long time as sometimes a bad batch of fuel or old fuel can cause problems. Old fuel can go "Off" and leave a sticky varnish like coating clogging injectors and sticking valves.
Try this. When your fuel tank is down to about quarter full and the engine is cold add a bottle of injector cleaner to the tank. Start the bike and let it idle until it is up to working temperature. Don't 'rev it up' because at idle your getting a stronger mix of cleaner going through the injectors. Once she's warmed up take her out for a good long steady ride then fuel up on the way BACK home.
If this doesn't help you'll need to get a Good bike mechanic to look at it as it could be a worn engine part or an electronics issue.

Yamaha... | Answered on Nov 03, 2020


Order the manual from Yamaha.

Yamaha... | Answered on Nov 03, 2020


The battery voltage before running the engine should be about 12 volts. Use a voltmeter, and check the voltage at the battery. After the engine is started, the voltage should go to about 14 volts.

Yamaha... | Answered on Oct 25, 2020


You do not have to. Just close the petcock so no fuel can drain out when removing the tank and keep the tank upright when removing.

Yamaha... | Answered on Oct 25, 2020


Check the speedometer cable. It should be attached to the front wheel hub and go to the speedometer.

Yamaha... | Answered on Oct 25, 2020


There is a neutral switch and starter circuit relay that disables the CDI module and prevents the starter solenoid from energizing.

Likely your start switch bypass attempt at the solenoid didn't account for the the CDI being disabled, so crank no spark.

You will need to verify operation of the neutral switch and the start circuit relay.

Do an internet search for "ttr225 wiring diagram" if you need a schematic.

Yamaha... | Answered on Oct 17, 2020


I remember these lightweight steeds that had an almost cult following in the UK, resulting in a large number of tuning parts becoming available at reasonable prices.
The noise of a gaggle of them pulling away from the lights all at once could and did break the windows of nearby houses.

The compression pressure of an exhaust tuned 2-stroke engine is necessarily quite low - because the cylinder capacity and the compression ratio "grows" at the rpm the reflected exhaust pressure wave effectively blocks the exhaust port and the engine power suddenly increases. Yamaha engines of that time were notoriously "sudden"...

I don't know the exact compression pressure but I would be happy if I did a test and achieved around 100 psi. My Suzuki of a similar design produced 105 psi on the kick starter. Much more pressure than that and there would be a danger of the fuel detonating in the cylinder when the engine "was on the port", usually resulting in a hole melted in a piston.

Yamaha... | Answered on Oct 16, 2020


If it is on all the time this usually means there is a possible problem with the bike or the engine. You need to get a Good bike specialist to look at this as it could be anything from a faulty sensor to a Serious engine problem. Get it looked at as soon as you can as using it with the light could be making it worse, (by worse i mean expensive).

Yamaha... | Answered on Sep 23, 2020

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