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Discussion Starter #1
I have a cylinder that will not run, I have checked every thing in the ignition system and have removed the carb and intake, and have removed the top and center parts of the valve cover but have not found any problems. Does any one know if it is possible for the gear on the cam to move and screw up the timing? The front cylinder runs because I set the timing with that cylinder but the rear one is dead. If its not the cam then I am at my end! If any one has guess I am all ears.... Thanks!!!!
 

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I have a cylinder that will not run, I have checked every thing in the ignition system and have removed the carb and intake, and have removed the top and center parts of the valve cover but have not found any problems. Does any one know if it is possible for the gear on the cam to move and screw up the timing? The front cylinder runs because I set the timing with that cylinder but the rear one is dead. If its not the cam then I am at my end! If any one has guess I am all ears.... Thanks!!!!
Quick question...what motor are you working on ??? :dunno
 

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1994 1340. The cam is a screaming eagle
Yes , you can remove and reset the gear on that cam. It is a good idea to remove the original gear from the stock cam and instal it on the SE cam .

You can rotate the cam gear on the cam to adjust valve timing a few degrees .
 

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If one cylinder fires and one doesn't it's not the cam gear. It doesn't have anything to do with one cylinder not having spark.
Are you running single fire or dual fire ignition ?
Are you sure the pushrods are in the correct positions per their color codes.
 

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Discussion Starter #6
Both cylinders have spark, it has a dual fire Dyna ignition. The engine was running great until it started backfiring through the exhaust. The motor is in a little rigid bar hopper I built a few years back, so I know every nut and bolt. The bike did set for 5 years while I was away, but has been running for the past year.
 

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Both cylinders have spark, it has a dual fire Dyna ignition. The engine was running great until it started backfiring through the exhaust. The motor is in a little rigid bar hopper I built a few years back, so I know every nut and bolt. The bike did set for 5 years while I was away, but has been running for the past year.
I'd be looking at the exhaust valve in the non-firing cylinder . :)
Easy way to check if valves are leaking. On compression stroke,TDC, apply air pressure to cylinder and listen to hear if air is escaping from exhaust or intake valves .

If you would like to check the timing of the gear on that cam, look to see if the keyways are still lined up together . I've not heard of one "slipping" but you never know. :dunno
 

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"The engine was running great until it started backfiring through the exhaust."

Possible a lifter wiped the bearings. The valve will still move when rolling engine over slow, but not enough when running.
 

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Put your thumb on the spark plug hole and crank the engine over. Have compression ?
 

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If the bike has spark then a compression test would be the next step.
It wouldn't hurt to pull the rocker cover and see if the valves are working right.
 

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Just from the description, sounds like a valve is staying open.......perhaps pushrod adjusted incorrectly?
Scott
 

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Well you say it ran..until it started backfiring...id say its not a pushrod...id look into a valve being burned up...compression check would be the best place to check as stated
 

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Discussion Starter #13
I found my problem guys, the intake was cracked. I put on a new intake and gaskets and it runs great. Thanks for all the input guys, I was about to go nuts, this one really had me stumped. Thanks again!!
 

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Happy ending, Yes!
 

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Ya gotta love them head scratchers.
 
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