JD 4x2 gator issues

   / JD 4x2 gator issues #1  

Sasquatch4100

Silver Member
Joined
Oct 25, 2011
Messages
146
Location
Pacific Northwest
Tractor
John Deere 4100 with 410 loader
I bought an old 4x2 gator with the Kawasaki 290 motor in it and its having some running issues. It was originally converted to run on LP, but seeing as someone ripped out half the system, I sourced a used carb off ebay to try and see if it'd run.

The carb came off the trike like gator with a slightly smaller motor and after researching the parts the only difference seems to have been the main jet, the pilots were the same. So I rebuilt the carb and threw it in. I also put new fuel lines in and a new oem pump. It starts, idles ok and revs to about 2k rpm or so then dies. I ran a compression check and it was well within specs according to the JD manual. I can get more power out of it if I choke it while it's near 2k rpm, if I choke it before that the motor will die. Spark burns bright and good. I heard mentioned that it might be a clutch issue, it uses a centrifugal clutch like a go cart or scooter. Thinking it might be a carb issue and who knows with an "ebay" carb I went ahead and ordered an OEM one from the dealer. Yikes!:shocked: So I'll throw the correct one in and at least it's a good start from there.
 
   / JD 4x2 gator issues
  • Thread Starter
#2  
Wow? No one eh?

Well, I picked up the carb at the dealer today and will install it as soon as I can. It'll be a little while. Have to fly back east for a funeral.
 
   / JD 4x2 gator issues
  • Thread Starter
#3  
Putting the carb on tonight.

Don't forget about me guys! I know some of you own gators!
 
   / JD 4x2 gator issues #4  
Don't own a gator ,but am always intrested in happy endings. Let us know if the carb is the cure. :thumbsup:
 
   / JD 4x2 gator issues #5  
Putting the carb on tonight.

Don't forget about me guys! I know some of you own gators!

Own a gator, but it has no carb:thumbsup: I hate carbs;)
Good luck!
 
   / JD 4x2 gator issues
  • Thread Starter
#6  
Put the carb on and it runs a lot better. It's not a powerhouse, which is a bit of an issue since we have such a steep hill to get up the drive. The specs say it's a 9hp motor. :( I'll tune it a little and need to replace some rubber snubs on the trans clutch and some other work.

Yeah, I'm not a carb fan either, but Its not worth switching to fuel injection or a diesel. I picked this thing up for next to nothing and I'm trying to keep it that way.
 
   / JD 4x2 gator issues
  • Thread Starter
#7  
It's not running top notch by far. Seems like it needs more fuel. Runs good(by previous standards), but lacks power and is very cold blooded. Also backfired a tad when i shut it off today. Did a whole bunch of research on it and finally found some similar issues. I'll post the results. Getting info on these things is difficult. Maybe the age?
 
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   / JD 4x2 gator issues #8  
Sounds like it is still running lean. have you checked for leak at the intake?

Also make sure the governor is pulling open when under load.
 
   / JD 4x2 gator issues
  • Thread Starter
#9  
Before I started fixing this issue I did research a lot on this problem and found nada other than some jetting changes. Soooo I tinkered with my ebay carb and did some trouble shooting to no avail. Went ahead and decided to put an oem carb on it to alleviate any issues with mix matched parts. Unfortunately there's unclear info on correct carb numbers for these things and thought it was best to return things to original and continue from there. Ordered and installed the new carb and BINGO it runs a lot better, but still some issues. I wasn't able to tune them out so back to the interwebs for research! Finally after multiple searches and comparisons and head scratching I came to a site, I think it was archived from the dark ages, but it had some great info on the exact problem I was having. A few guys ran the issue down and came up with a few fixes of their own.

Guy A: Had gator a while and then POOF! One day he hit a bump and had the identical issue as me. After taking it to the dealer many times as it was still under warranty and had them scratching their heads a while, they found out it was missing a small restrictor that fits between the air box and the intake tube on the fresh air side. Being fixed he took it home and it worked for awhile and then it happened again. Knowing the issue he bought the two dollar part and glued it in.

Guy B: After tinkering with his and encountering the same issue he tinkered with it and rejetted it and got it to work and increased power.

While both guys said it made theirs run better, guy B said after rejetting and not reinstalling the restrictor his had more power. Both wondered the reason for the restrictor. In my experience the restrictor could match the airbox to the size of engine because it's used on many different models or efficiency/epa requirements although I don't believe this truck had to meet clean air issues back then. I vote for the first one. It's far easier to install a 2 cent piece of plastic than redesign an air filter box or worry about correct jetting etc.

Being a tinkerer and being as these items (restrictor and jet) are cheap and I want more power I'll try both A and B and see how it works!

Let you guys know when the parts come in.

FYI here's the breakdown. It's Item 14A that's MIA. Not sure what 14B is all about.
 

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   / JD 4x2 gator issues #10  
I am guessing that I have worked on thousands of engines < 20 HP, and the only time I have seen a restrictor like that, it was intended to balance airflow into the housing. In other words, there was heated air coming off of the motor cowling that fed the carburetor, and also a second air source or something like that. On any engine that I have seen, you could take the air filter cover off and the engine would run exactly the same. The reason for the dual input feeds that I have seen is to help the engine run without a choke in colder winter conditions, that might otherwise cause freezing moisture in the throat of the carburetor.

So I am suggesting that before you chase that one too much, just take the cover off the air cleaner and see if that changes how it runs. I bet it won't, and that will tell you that the restrictor is there to take a standard air cleaner housing, and balance the air flow into it from two sources.

With that said, carburetors take a certain amount of vacuum to operate properly, and if there is an air leak, even a small one, near the base of the carburetor it will behave similarly to what you are saying. Another thing that will cause this is a intake valve that is sticking, has a poor seal, or a weak spring.

Good luck!

Tom
 
 
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