dpaxson

Member
Sep 30, 2006
54
0
Hi
The weather here in cleveland just turned cold and I have been trying to get my 81 rm 125 running great to sell it. Unfortunately the bike refuses to start cold. The only way I can get it started is to put a space heater up to the engine or squirt some gas in through the spark plug hole. Is this normal for an old bike? If not does anyone have any ideas about what I can do to make it start better? thanks for any help.
 

CRazy250

Member
May 28, 2006
334
1
clean your carb if you havent, old gas turns into varnish. check to see if plug is fouled or bad, does it have good compression?
 

kx125412

Member
Mar 30, 2006
341
0
Well my bike has a super picky carb. Make sure yours is cleaned extremely good. Check compression, it should be around 150-175 psi. And check which clip your jet needle is set at. You'll have to raise the clip (lower the needle) so that it is richer. I had to do this to mine to start it up when it was really cold to run it long enough to fog the motor. It wouldnt start if the needle was too lean.
 

kx125412

Member
Mar 30, 2006
341
0
My bike normally starts 1st or 2nd kick all the time but when I tried the other day to fog the motor it was aroun -5 celcius and it did not want to start at all until i dropped the clip on the needle.
 

apb

Member
Feb 1, 2005
150
0
kx125412 said:
You'll have to raise the clip (lower the needle) so that it is richer.
You said the opposite of what you probably meant: you need to lower the clip (which raises the needle) to make the mixture more rich. But it may also help to switch to a larger pilot jet as well, for the cold weather starting...
 

wirefryer#85

Member
May 26, 2006
158
0
My RM has always been indifferent to the cold, though it likes to foul plugs a bit more when it gets below 40 degrees or so.

Two old school tricks I have seen work are;

Gas on, choke on, remove gas cap and using your mouth, pressurize the tank with your breath and hold for a few seconds to ensure the carb bowl is full. Try to start it.

Gas on, choke on, lay the bike on its side until gas come out of the overflow hose, effectively flooding the engine, then kick as normal.

The main reason most cold starts are a b*tch is there isn't enough fuel in the chamber.
 

apb

Member
Feb 1, 2005
150
0
dpaxson said:
thanks for all the help guys. I think I'm gonna raise the needle to try to richen it up and see if that works

And also make sure you use wirefryer's recommendation of laying the bike over till the overflow runs in order to get more fuel in the cylinder -- it makes a big difference. Good luck :cool:
 

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