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I am new to the forum, had a stupid attack last time I fueled my 630. Didn't check the end of my fuel hose, had some bug's, mud, etc. Sent it into the tank (found out when I unhooked it). Now I can't get my old tried and true 630 to fire. I have the service manual's on order. Don't know what I am doing. Any suggestions about taking apart the fuel manifold on a 630? I sure would like to keep from blowing myself up.
 

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Welcome. Sorry, I am not familiar with LP engines, but I'm sure that someone will be along that can help.
 

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:wgtt:

I work with a lot of LP engines. They're practically identical to the gasoline counterparts, aside from the fuel system. First and foremost, do you have spark? If there's no spark, then troubleshooting should be just like a gasoline engine. If you do have spark, then we'll dig more into the fuel system.

I'm not intimately familiar with how Deere set up the LP tractors, but you should have a 'lock off' and a 'converter' before you get fuel into the carb or throttle body. Newer LP equipment uses electric throttle body injection, older stuff like the 630 should still be an LP 'carb'. You will get liquid LP up to your converter, which should normally change it to a gas by heating it with engine coolant. Normally your converter would have four lines going to it, LP in and vapor out, along with coolant in and out. Coming from the tank, the line should go to a lock off. On an older machine it's usually vacuum operated and shuts off the flow of LP. Crack the line going into it and see if you have pressure there. If so, crack the line coming out of it and check for pressure while cranking. You'll hear/ smell LP coming out if it's there. If that checks out, then move to the converter and verify fuel in (crack a line) and vapor out. If you're getting high pressure LP out of the converter on an older machine like yours, then the converter has failed. You should get a fairly low pressure, usually 2-5 PSI. You will only get that while cranking or running, so you may need an assistant to crank the tractor while you check for output.

If you got dirt or contaminants into the fuel system, it could be plugging up the lock off or there may be a 'filter' somewhere in the system before the lock off. I'll see if anything can be found on JD Parts in a bit.
 
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