rt 125 not starting in the cold

[timebandit43]

[color=#0000Hi all my rt125 is stored outside and is having trouble starting it ran about 4 weeks ago and has been serviced and mot'd 3 months ago.
all thats happening is turning over and can hear poping from exhaust and thats it till flatten battery
PLEASE HELP
BF][/color]

[Jamie]

Re: Starting problem
by DAVID THOMPSON » Sun Apr 19, 2009 2:19 am

THE 125 CC MOTOR is hard to start after it has set for a while
i put a small hose in the rubber stopper on the top of air intake at the carb and inject about 10 cc of fuel past the carb slide into the rubber intake area in front of carb
take hose out try starting bike full and closed throttle hoping it will draw enough vacuum to prime the carb
this will usually work may take more than once
dave
but also check plug and see if it is dry or wet

Try this it worked for me

[OSPRNG]

try removing the seat and hand-cupping the air intake when you start with a fully charged battery.
just keep the hand over it as tight as you can and try starting.

did the 'service' include carburetor cleaning? how long has it ran for prior to that?
how old is the gas in the tank?

[timebandit43]

hi there thanks will give it a go in morning, didnt find out what service included (took it to garage), fuel in tank is 3 month old and it ran for 3 hours prior to now,
and thanks again.
merry xmas all and a good new year
steve

[djsbriscoe]

Hi.
Try the following.

1/ Charge the battery fully.
2/ While the battery is charging remove the spark plug
a/ Check the spark plug colour and if it is wet with petrol or dry. The colour of the plug should be a light tan colour. Black is too rich, White is too lean.
b/ Place the plug cap on the plug and SECURELY EARTH THE SPARK PLUG AGAINST THE CHASSIS I.E WRAP SOME COPPER WIRE AROUND THE PLUG THREAD AND AT THE OTHER END WRAP AROUND SOME METAL EARTH POINT ON THE CHASSIS. It is important to earth the plug or you WILL damage the cdi Unit. Check for a spark.

3/ If there is a spark you can rule out major ignition problems.
4/ If the plug is wet with petrol too much petrol is flooding the cylinder. Dry out the plug. Put the plug back and try to start again.
5/ If the plug is dry this eliminates flooding as a cause.
6/ The float valve may not be closing properly and too much petrol may be flowing into the engine. This can also happen if the petrol tap is left on with the bike standing. As the carb is inclined downwards toward the engine intake petrol can flood the engine easily.
7/ Remove the dipstick and check if you can smell petrol in the filler hole or on the dipstick.

I assume you use the choke when you try to start the engine. If yes, this is the next thing you should check. Make sure the choke cable is working properly and that the choke plunger is being pulled upwards properly againt spring pressure when you operate the choke lever.

There is enough for you to be going on with above. Please get back to us and let us know how you get on.

David.

[timebandit43]

Hi all
Sorry for the delay in repling but been working over xmas and new year.
right here goes I have drained the petrol (incase was contaminated) and changed the plug and recharged the battery put new fuel in, tryed to start and nothing, all it does is turn over at what point do I inject petrol into the carb incase float stuck (please remember am a novice at this stuff) and can show me were on carb it gets put in.
yours a very subdued mz owner.
regards steve

[djsbriscoe]

Hi,
Have you checked for a spark at the plug? To check this
a/ Remove the plug.
b/ Can you smell petrol on it? If so petrol is getting to the combustion chamber. If no petrol smell, there may be a fuel problem.
c/ Place the thread of the plug against any metalic engine part with the HT lead connected.
d/ Turn the engine over and look for a spark.

Have you checked the air filter to see if it's damp or wet?

You can check if the float is stuck by observing the petrol flowing through the inline (to petrol pipe to carb) fuel filter. First drain the carb by loosening the drain screw at the bottom of the carb (where the plastic overflow pipe is). When the petrol is drained out (with the petrol tap off) re tighten the screw.
Turn on the petrol tap and you should see petrol flow through the filter and then stop. If it does this, the the float is OK. If you don't see any petrol flowing the float valve is stuck closed. Time for a carb stripdown and clean.

Has the engine run well previously? If so, try to remember when and if you can figure out what's changed since.

Sorry if I'm repeating myself above. Just trying to help you trace the problem logically and hopefully quicker.

David.

[timebandit43]

hi all well heres the next chapter in the rt saga lol
well got a spark at the plug and when I injected fuel in the carb it ran then when connected back up to fuel line and tank it wouldnt start so guess thats carb needs stripping then, is it a hard job and can it easly get naffed up. just wondering whether to put an sos out to any helpers in the area.
yours steve

[Jamie]

Try the same thing again, only this time connect up the fuel linebefore you inject and start it. It does take a few tries.

Jamie

[DAVID THOMPSON]

AS ABOVE
hook up gas and prime and crank the vacuum draw on the carb when the engine runs will suck new gas into the small
places in the carb that are not filling up
and then it should run
the holes in side this small carb are very tiny
trying to start this bike with throttle open is a waste of time
i had fits with mine till i got a grasp on the problem
but its hard to explain in words here
prime and start several time with both open and closed throttle
and hooked up to a supply of good gas
dave

[Anders]

My top tip is to get a can of Engine starter/cold start spray (aerosol), just spray some into the carb intake or air box (a good few seconds of spraying) and the engine will run on the aerosol long enough to draw fresh fuel into the carb.

When not staring stubborn engines it can be used to find air leaks in the intake, quick degreasing of metal and painted parts, cleaning/carb holes tubes etc.

[Jamie]

That worked for me as well

[timebandit43]

Hi guys
well did as stated above, when the damp start ran out it cut out , so tryed priming again with fuel and it ran but cut out once the fuel was used, did this several times until battery failed on me , so charging it at the minute, if i take the plug out and continue to put fuel in at the back of the carb with a funnel and bleeder pipe with fuel would it make the carb prime itself or not. or is it going to be carb strip and cleen.
thanks again for the help.
steve

[DAVID THOMPSON]

these are fussy about starting check that throttle cable has free play
if slide is held up by throttle cable carb does not pull enough vacuum to prime
and below 20deg f lots of luck
dave

[djsbriscoe]

Hi,
Have you tried starting it with the choke on?
Try starting the bike with the choke on and throttle closed and then again with the choke on and throttle fully open. Both with a charged battery of course.
If that doesn't work take the carb off and give it a good clean.

David.