Motorcycles Logo

Related Topics:

A
Anonymous Posted on Oct 27, 2012

1987 yz 125 no spark not starting

Road bike test had put 330 main jet in it road it for about 15.min hard through the higher gears as we do flat track, and noticed it started to break down at the higher reving range then seem to cut in and out on the way home. then would not start at all then i changed plug no differance also checked plug for spark and there was no spark, i think maybe coil as it looks fairly old or maybe stater.

5 Related Answers

tombones

  • 3567 Answers
  • Posted on Apr 02, 2009

SOURCE: hard start, trouble idleing

Drain the carburetor. There should be a screw on the lower side of the carb float bowl. Remove the screw then replace it after the fuel drains. Turn the gas back on and wait a minute for the carb to fill with gas. Install new stock spark plugs. If the bike doesn't start and run properly then shut off the gas and remove the carburetor from the engine.

Remove the float bowl and clean the entire carb with a spray carb cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray into all the little airways and fittings in the carb. This process should get you back on the road.


Please rate this solution. Thanks!

Ad

tombones

  • 3567 Answers
  • Posted on Apr 11, 2009

SOURCE: bike only fires once

Okay, let's have a look at it. Say Ahaaa.
The probable cause of the problem is not the spark. Get a fresh set of Stock NGK spark plugs, ground the plus to the engine, and check each cylinder for spark as the starter button is pressed for 3 seconds or so. I will wager that the spark is present.

The likely problem is the fresh gas was put into a very rusty gas tank. Bits of rust now inhabit your carb and are having fun plugging up the carb. Look at the gas valve. With a little luck there is a small bowl behind the valve. Remove it and tell me what you see in the bowl.

Knight 007

Murtaza Akberali Versi

  • 767 Answers
  • Posted on May 23, 2009

SOURCE: yz 125cc 2003

Black spark plug means too rich , you will have to replace the spark plug since it has foul up and reset the air mixture screw on the carburator 2 and 1/2 turns outwards.
Check the air filter too.
Hope this helps.

Anonymous

  • 440 Answers
  • Posted on Aug 14, 2009

SOURCE: I have a 2005 yamaha venture royal star and i just

If it wont do anything then it is likely that youve popped a fuse
But it sounds like the battery isnt being charged properly. Make sure the voltage across the batt terminals is at least 13.5v at tickover rising to no more than 15.5v at higher revs
Ride-Safe
Bike-Doc

Please mark this as helpful (if it has been!!)

Testimonial: "thanks, I will try what you reccommended"

Anonymous

  • 1 Answer
  • Posted on Oct 15, 2009

SOURCE: engine turns over but wont start

could that be a possible fuel line crack? or the pet **** is fouled up. i got the same problem found 1/2 in crack in the fuel line. from trying to start it before i found the crack i dryed out the carbs. im a girl and its my first bike just learning

Ad

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
1answer

My yz 125 started to bogg down when i put my bike in 3rd gear and i drove it back the next day i went to wash it and i tried to start it. it started but bogged right down till it shut off no matter where...

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!
0helpful
1answer

Kx 125 problems

it runs but sputters.
that can be 2 things.
First idd your sparkplug cap has had it (get a new 1 from the parts store)
2nd it could be that your getting to much fuel in top end of your revband.
easy to check just run your bike a few min with a new sparkplug and look at the color.
Wite is not enough fuel.
Brown is perfect mix.
black is to much oil and if black and wet its to much fuel.
try this test and maybe you'll find it
4helpful
2answers

How do you set the timing on a 01 yamaha yz 125 or why else would it be melting the spark plug prob off with a 32:1 fuel mix and the plug that goes in the bike from the factory

melting spark plug is too lean. exhaust gas high temps caused by too much air. your oil to fuel ratio is correct, but your air to fuel ratio is not. adjust your needle clip position to add more fuel to the carb by lowering the C clip. this will raise the needle, giving you more fuel for the same amount of air. also check air filter element for tears.
1helpful
1answer

Yz 125 wont start

gunk in carb jets pluged
0helpful
1answer

Need spects for carburetor main jet on mikuni ucal and spects for pilot air jet 1 and pilot jet 2

http://www.cmsnl.com/yamaha-yz125r-2003_model11245/partslist/A-12.html

Site above has all the parts and specs for your bike. Jet ranges are large for a YZ as many mod's are available and riding conditions contribute largely to a peaky 2 banger. Start with #40 pilot, and #420 main. Trial and error from there. Cheers.
0helpful
1answer

How do you know you should go with a bigger main jet? What exactly would it do for my 2001 YZ 125?

a bigger main jet will make the bike run richer which means more gas.
unless you have changed something on the bike which would involve a bigger main jet like porting or something like that. I wouldn't mess with the jetting.
if you are trying to get the bike tuned properly, there is an adjustment screw on the carb, but I would put it in the hands of a pro.
You can easily blow your bike up messing with jetting.
1helpful
1answer

Hello, I have a YZ 80 and i was wondering why my

Look at ?

crank seal (drawing air)

ring wear

main jet (blocked jet's)

fuel starved carb
1helpful
2answers

Bike not starting

Its easy to test. take your plug out and ground it then crank your motor and check for spark. If no spark then its your ignition. probably a bad capacitor. If its your fuel system, drain it then, clean it then refuel.
Not finding what you are looking for?

63 views

Ask a Question

Usually answered in minutes!

Top Yamaha Experts

vince

Level 3 Expert

2530 Answers

Steve Sweetleaf
Steve Sweetleaf

Level 3 Expert

1212 Answers

littlewheel

Level 2 Expert

122 Answers

Are you a Yamaha Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...