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Discussion Starter #1
I am attempting to repair an EXT special (550 cc). The problem is with the engine. The engine starts easy, idles fine, but when attempting to increase engine speed, the engine is very boggy and cannot move the sled. Even with drive belt off it has a hard time to get to 6000 rpm. Engine has been totally gone through mechanically and all internal workings meet factory specs. Pressure test is excellent. Carbs have also been worked and are good. Factory main jets are installed (310). Previous owner tryed different jets with no luck. All coils meet factory resistance values and reveil no visual problems. CDI cannot be tested by myself. Timing required retarding the stator ass'y as far as possible to achieve factory specs. As engine is reved up the timing light has trouble operating and timing advances 6 degrees or more. Seems to me I have an electrical problem. Suspect CDI as this is only electrical component I cannot evaluate. Can anyone knowlegably confirm this or point me in the correct direction. I hate buying parts and using the trial and error method of resolving a problem as parts are not cheap.:confused:
 

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1,054 Posts
congrats, have fun in the snow.
 

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347 Posts
Be very careful running a carbed two stroke with no belt. I've seen plenty run away on their own and destroy every factory spec in the engine.
 

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Vintage Sled Pilot
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533 Posts
Make shure your air screws are out 1.25 turns to start. Also recommend cleaning the carbs. Make sure to pull the pilot jets and clean them with a wire and carb cleaner. Good luck!
 

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on the air fuel screw one full turn out is perfect and and your idle screws 2 1/2 out. make sure your carbs are synced idle screw and air fuel also check the pilot jets and the mains. that should tune her right up
 

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34,103 Posts
hi i have and 89 el tigre. it smokes a lot. it wont go either i will hold the throttle wide open and it wont take off? what could it be?
Put new plugs in!
 

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Also check your plug boots sometimes you just have to pull them off and cut the wire back a little to have a good connection. That's if there the rubber boots i wouldn't try it if they're plastic.
 
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