Hi my grandson has a 90 scrambler that he is having problems with. When you give it gas it will go and then will stop moving. When you let off the gas and then give it gas again it will move but only a short distance. It does not die. Do you have any ideas what can be wrong? seiv5

 

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Here's a couple of ideas you may want to try....

- Clean the air filter, replace the gas filter and ensure its getting good gas flow. Install fresh gas.

- Check the color of the spark plug. A properly gas / air mixture would create a beer bottle brown color on the plug. If white, then its running too hot (too lean).

- Regardless of plug color, you may have a dirty carb. May have to remove the carb and give it a really good cleaning. If you are uncomfortable with this, a few local motocross / automotive shops can clean it in the solution bin. And blow the jets out with their air hoses.

- If you are getting gas into the air filter, then a reed may be cracked. While doing a pressure test, check the reeds.

- If you have a Spark arrester on the pipe, remove it and ensure its nice and clean. A plugged pipe can make an engine run very weird as well.

- If you do all this and it continues to run "weird", you may need to give the engine a pressure test. To do this, remove the carb, pipe and pressurize at 5 lbs for 5 minutes. If pressure drops, then a crank or other seal / gasket is leaking.


Hope these ideas help....

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