Why is my yamaha DT 125 1992 so very hard to start from cold?
Answers:
May be the choke is broken -the cable may be broken or the plunger system may be disconnected or broken inside the carburetter, may be the spark plug is worn out, spark plugs work better when they are warm or hot. If the bike has been sitting around for a while then the petrol will be absolutely shot.
May be the bike is just grumpy - try chatting to it!
Check that spark plugs are clean, the battery is FULLY charged and that you are using right grade of petrol. Next, check the choke is actually working.
If they are all alright it might be that the cylinder compression is low. This is generally caused by badly seating/worn valves. Alternatively it could be general bore wear. Get it re-lined (re-bored).
-It might be time to rebuild the top end - piston, rings, cylinder.
-Also check the reed valves. Remove the carb, intake manifold and reed valve. Hold it up to the light and make sure there are no gaps between reed and reed block.
-Clean the air filter.
-Carb might need cleaning. Remove the pilot jet (smallest one in the float bowl), hold it up to the light. You should be able to see through it.
maybe its something to do with the choke
Go with GaurdrailJim's answer. Chances are that it has been riden by a series of 17 year old "Back Street Heros" and just needs some TLC.
Make sure you don't open the throttle with the choke on when kicking it over. This overides the choke system.
Kick it with a closed throttle, not the my wrist is connected to my knee with a length of string scenario, that many do unknowingly.
What a great excuse to get in and strip it down.
Go for it, see whats really going on under the plastics.
Yea , take the engine to bits to see how it works. They are simple to work on and will teach you something. Could need new crank seals, its pulling to much air in.
coz its a rubbish bike
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