Johnny Barrett /

I Cant get my DT50 to start...Ive Cleaned the Carb and Checked the Jets, Im getting a spark (I nearly took my bloody hand off trying to find out that!) Ive got enough compression, The Petrol Is getting through fine..But i still cant fire the bloody thing up!! PS...The throttle lead and pin is held into the top of the Carb Via Cable Ties (Would it make a difference)..

Any help would be appretiated..Cheers


Ron Brown /


This is a tough one to answer, as you are effectively saying there is nothing wrong, except that it won't start!

You need very little to make a motor run. A good spark at approximately the right time, a reasonable gas/air mixture and some compression will always at least make it fire occasionally.

A good spark means it has to be a fat healthy spark. Often, you can see a spark when the plug is in the open air, but it is not powerfull enough to jump the plug gap under compression. Even with a good spark, if the insulator is leaky, the spark current can leak to ground, if that is an easier path than jumping the gap, when under compression.

If you are suspicious, check that the timing is close, firing close to top dead center, then install a new plug, splash a small amount of gas into the intake and see if it will fire.

If you get a short burst, then it quits, you have fuel problems. If it won't fire, you have ignition problems, possibly a leak somewhere else in the ignition wiring.

You can check for this by using a spare plug with at least twice the normal gap. In the open air, you should still get a good spark, if you do not, the plug cap, wire, coil or magneto is leaking.

Try this and let us know what happened.



If I'm guessing right... That is a watercooled 50cc 5 speed CDI ignition fully street legal mini motorcycle...

And I believe it has a real carburetor... With a "pilot jet'.

It is probably clogged.

It is a small brass jet... to find it you pull off the float bowl and turn over the carb..and it is down inside a hole and you need a small narrow blade screwdriver to get to it.

If that is not it try a brand new plug like Ron said.

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