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Discussion Starter #1
Hi,
I've got a xuv 550 with a Briggs engine. It runs but has no power. I've got spark and fuel getting the both cylinders but the front cylinder did not appear to be firing, just a wet plug. I tested the compression and found no pressure in the cylinder. There's no oil leak or sign of a head gasket being blown. I've heard that on these air cooled engines the valves could start the stick due to deposits. I remove the valve cover and the valves seem to move freely. Any suggestions? This may be answering my own question, but I did notice what could be a crack, but could also be a mold line, in the block below the exhaust port, has anyone had this happen.
 

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With no compression, I'd blow some air through the spark plug and ID where it is coming from. Don't need much air pressure. It could be the valves are not seating correctly or worse.

If you had a dial indicator, place on each valve and measure stroke. Compare two exhaust and two intakes to see if there is a difference.

Good luck and report back what you find.
 

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Perhaps this will help?

 

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Discussion Starter #4
Turns out after closer inspection, there are several hairline crack in the engine block itself. Even though they are hardly visible at first, I'm guessing that's the problem. I'm curious what could have caused this in the first place? The engine only has about 390 hours on it and has had all regular schedule maintenance.
 

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Turns out after closer inspection, there are several hairline crack in the engine block itself. Even though they are hardly visible at first, I'm guessing that's the problem. I'm curious what could have caused this in the first place? The engine only has about 390 hours on it and has had all regular schedule maintenance.


Dang... if you decide to re-power your Gator, contact @dane

Dane re-powered his 550 with a Honda engine, to my knowledge he has been very pleased with the outcome.
 

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Are you certain they are cracks and not small inconsequential casting defects? Before discarding the engine, perhaps it is worth confirming using a dye penetrant crack detection kit (spray).

It would be hard to pass enough air through hairline cracks to register zero compression. Low pressure is plausible but not zero unless they are major cracks.

Curious... Does this block use cast iron sleeves?

Not trying to second guess your visual observation... Just hoping the engine isn't toast and it is something repairable for minimal dollars.
 

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Discussion Starter #7
Not sure if the engine is sleeved. As far as the cracks go, the first I questioned could be a die mark, but asked a coworker to look too and he spotted the others. One of which extends up to the head.
 

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I would do a blow down test before tossing the engine just to make sure that you are correct about the cracks.

I had so much trouble with my Briggs engine that I replaced it at about 100 hours. If you want to see some pictures of what the engine looks like out of the Gator and cleaned here is a link when I sold the old engine. Maybe you can see the mold lines to help confirm if you have cracks.


If you are considering going to another engine here is a link to my conversion on the other forum. You will see that it was not a simple swap so carefully consider if you have the skills and tools for the job before beginning.

I love the Honda. The additional power has been great and it's been totally reliable. I hunt and use the Gator as a mobile lighting source when dressing game and the old Briggs engine would load up badly if left idling for long periods. I can completely process a deere and the Honda still purrs nicely while powering the lights.
 

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Those lines dont look like cracks to me.
You should check the compression in the other cylinder for comparison's sake before you pull the engine. I may be wrong, but I think that engine has a compression release. If it does, I think that feature makes it tricky to do a compression check.
 

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So what did the OP find after performing the recommended tests above (compression, leak down test or other) diagnostic steps to confirm root cause?

It would be nice if everyone learned to complete the threads.
 
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