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Leak down help


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No plugs are required for either the intake or exhaust, and in fact, if used, they would defeat the ability of the test to locate leaks at the valves.  

 

Yes, it should run with 13% leak down.  Briefly, leak down testers are not made to a single standard.  The size of the orifice between the two gauges and the air pressure used for the test both influence the outcome.  The only really accurate thing that can be done with one is to compare the engine's current condition with an earlier baseline test.

 

Nevertheless, in order to run, you need compression, spark at the right time, and fuel.  Check your cam timing, check that TDC as marked on the flywheel actually is TDC at the piston, check for spark.  If that checks out, check to be sure fuel is being delivered to the carb.  Most starting problems traceable to the carb, and most of those are the result of an incorrectly set up or faulty pilot circuit.  Pilot jet orifices in Keihin carbs are very small, and can be functionally blocked by nothing more than a dried film of gas. 

 

Read: https://thumpertalk.com/topic/681801-bike-wont-start-dont-know-what-to-do/#entry6879695

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Yeah I just used a standard leak down  tester, and a breaker bar on the flywheel to keep the piston from pushing back down.

 

My carb has been apart more than a few times and just in case I even replaced all the jets with brand new ones to eliminate chances of it being a carb problem.

The timing was off when I got it but have since corrected that so that the marks are lined up with the top of the head at TDC now.

 

That's where I am now....lost as to what to try next.

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No plugs are required for either the intake or exhaust, and in fact, if used, they would defeat the ability of the test to locate leaks at the valves.  

 

Yes, it should run with 13% leak down.  Briefly, leak down testers are not made to a single standard.  The size of the orifice between the two gauges and the air pressure used for the test both influence the outcome.  The only really accurate thing that can be done with one is to compare the engine's current condition with an earlier baseline test.

 

Nevertheless, in order to run, you need compression, spark at the right time, and fuel.  Check your cam timing, check that TDC as marked on the flywheel actually is TDC at the piston, check for spark.  If that checks out, check to be sure fuel is being delivered to the carb.  Most starting problems traceable to the carb, and most of those are the result of an incorrectly set up or faulty pilot circuit.  Pilot jet orifices in Keihin carbs are very small, and can be functionally blocked by nothing more than a dried film of gas. 

 

Read: https://thumpertalk.com/topic/681801-bike-wont-start-dont-know-what-to-do/#entry6879695

 

You use them one at a time to isolate the leak, if it's really bad

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