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Discussion Starter #1
Hello everyone, I have been lurking here for years now and the contributors here have helped me MANY times, so thank you!

My problem, as described in the title, is that the engine on my 2011 420 trx will not start. It cranks when I press the starter, but that's it. I know it is not getting fuel to the cylinder because the spark plug is dry immediately after trying to start it. Pulling the fuel injector out of the throttle body and hitting the starter, I can see that the injector is spraying gas. If I loosen the throttle body hose that attaches to the motor and hit the starter, I see gas spray out from the throttle body. I changed the filter inside the fuel pump and cleaned the fuel injector by spraying some Seafoam through it. I tried starting it again and got one little cough out of the engine, but the plug is still dry.

My only next move, I think, is to check and adjust the intake valve. Please advise if there is anything less invasive that I am missing.

Thank you again for being such an amazing resource and let me know if this is not the appropriate place for this post.

Alex
 

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Hello and welcome to the forums!

Is your motor getting spark at the plug? A known good NGK spark plug? Have you checked the compression on it to eliminate the possibility of a bent or stuck valve or a timing chain jump? Got the FSM handy?
 

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Discussion Starter #3
Thnks for the reply Retro!

Yes, nice blue spark on the brand new NGK plug. Compression test was 71 psi with throttle held open. Thank you for the service manuals.
 

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You're very welcome! Try spraying some carb cleaner or something that will ignite (ether if thats all you have) around the throttle body to check for cracks in the manifold or other air leaks. Be careful about catching it on fire though... do it outdoors with a fire extinguisher handy.

Try putting some fresh gas in the cylinder through the spark plug hole then reinstall the spark plug and see if it fires up on that.
 

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Discussion Starter #5
Tried starting it with brake cleaner and wd40 by spraying into air intake, I will try again spraying around throttle body. For the gas in the cylinder, I tried that also, but not very much gas. To be precise I dipped the plug into the gasoline so that there was a drop hanging onto the plug, like filling the spark gap. That's like, a drop or two of gas. And it didn't start. How much gas should I put in the hole so it does not flood?
 

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I'd put about 1/2 ounce of gas in the cylinder and try starting it. If it fires up that eliminates a lot of stuff from the possibilities list...
 

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The best way is to remove the air filter element and spray gas into to opening to the throttle body. A dry plug could mean the injector isn't spraying enough fuel.
 

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It seems to me that your compression is way low. Maybe the compression release mechanism on the cam shaft is jammed.
 
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