CBR125R IGNITION ISSUES

kevinjstanley · Derestricted Danger Joined: 29 Dec 2014 Karma :

I HAVE A FULL CHARGE, SPARK AT THE PLUG AND FUEL, CHECKED VACUM HOSE AND FUEL PIPE, SUCKED ON VACUM HOSE AND FUEL FLOWED.
AFTER COMING HOME ATTEMPTED TO START IN COLD CONDITIONS AND IT WOULD NOT DO SO, ALMOST AS IF IT WAS OUT OF JUICE..TURNS OVER WITH OCCASIONAL BACKFIRE BUT NO IGNITION.
TRIED A LITTLE BIT OF FUEL IN THE SPARK HOLE AND RETRIED WITHOUT ANY JOY.
LE I SAY I HAVE SPAQRK BUT NO IGNITION...ANY IDEAS

bradh511 · Scooby Slapper Joined: 01 May 2009 Karma :

Few simple test i would do check the coil with a multi meter try a new plug... Test the voltage from magneto and pick up for and flywheel woodruff key...
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Theory 11-10-12 lets hope i get mod 1 and 2 done by the 18th of jan 2013 Smile

P.addy · Red Rocket Joined: 14 Feb 2008 Karma :

Or check the choke is working... prone to seizing up.

kevinjstanley · Derestricted Danger Joined: 29 Dec 2014 Karma :

hi
8 months ago 2nd hand carb went on due to seized choke [it had been stood a while]
I have got a great spark at the plug so coil would be ok and plug.
I cant help thinking it is a fuel issue, the carb is standard so if I see juice coming out of the tank hose then the carb is getting juice I assume...but again if I have spark and what looks like fuel why does it not start.
I will tank the tank off and the carb tomorrow , strip the carb and take a look see.
In the past I had a contamination issue with the tank rust flakes making the bike cut out after a while but for the last 3.5 months no problems at all after the vinegar fix

more thoughts please boys

bradh511 · Scooby Slapper Joined: 01 May 2009 Karma :

It could be stuck choke but doubt it would be should fire cold or just rev out surely and cut out when hot... But its back fireing so fuel is getting into the bore and its either sparking at the wrong time or its not got a good spark try a new plug at 3 pounds
____________________
Theory 11-10-12 lets hope i get mod 1 and 2 done by the 18th of jan 2013 Smile

bradh511 · Scooby Slapper Joined: 01 May 2009 Karma :

If choke is stuck will end up with a wet plug same as it not fireing
____________________
Theory 11-10-12 lets hope i get mod 1 and 2 done by the 18th of jan 2013 Smile

kevinjstanley · Derestricted Danger Joined: 29 Dec 2014 Karma :

kevinjstanley · Derestricted Danger Joined: 29 Dec 2014 Karma :

hi all
so
I have taken apart carb, everything as it should be , a very little dirt but now a clean carb, choke slider is fine.
connections between airbox to head are fine with no cracks in the rubbers.
great spark.
but I am not sure about juice to the cylinder ??? took plug out twice and it was dry, did the squirt into plug hole with tiny bit of juice to no avail.
how would I test that the vacuum is being created for the fuel tank from the engine.... I was told that perhaps I have a rings issue?
your thoughts please

kevinjstanley · Derestricted Danger Joined: 29 Dec 2014 Karma :

hi all

save your self effort and listen to your peers...

I have had starting problems as you can see from previous posts I have felt that I was short of juice due to a good ..no great spark and no firing...dismantled carb, emptied tank and cleaned it out, and still it would not start...even the chamber appeared dry when I took plug out.
I give up I thought no idea other than perhaps rings issue and no vacuum for the feeding of juice.

HERE IS THE LISTEN BIT:
I WAS TOLD CHANGE THE PLUG BY MORE INTELLGENT PEOPLE ON HERE...I DID NOT BECAUSE I WAS GETTING A GREAT SPARK WHEN I TURNED ENGINE OVER AND PUT PLUG NEXT TO THE HEAD.

I JUST PUT A OLD NGK PLUG IN I HAD.
IT STARTED FIRST PRESS OF THE BUTTON... I STILL DONT KNOW WHY WHEN U GET A SPARK OUTSIDE OF THE CYCLINDER AND A BLOODY GOOD ONE... that it would not start , yet a old plug put in did....
thanks all who assisted me with this issue