HPX falls on its face when taking off

[2005HPX]

Alright, whats the fix on a HPX? When you go to take off, it just falls on its face, pops through the air intake and sometimes just dies.. Buddy cleaned the carb out good, but still no better. This happens when its fully warmed up or cold. You can use the Gator, but just have to put up with these issues.. 2005 w/ 257 hrs.. Draining gas and putting in fresh makes no difference. :Cnfsd:

[Jake B]

Did he take it completely apart and replace all the gaskets?

[2005HPX]

No, took somewhat apart I think and put in some kind of cleaning machine..

[Jake B]

It might be worth it to tear it down completely and remove the jets. That way you can spray out all the passages. I asked a JD Tech about rebuilding the carb ($60 parts) and he said it works sometimes (1 in 3) but most of the time they just replace the whole carb ($350). Mine started stumbling going up a hill the other day so I removed the carb and cleaned it. It's still in pieces, so I hope the rebuild works.

[Jake B]

I had to clean my carb the other day. Here is the write up(at bottom):

HPX Carb Cleaning (http://www.johndeeregatorforum.com/forum/showthread.php?13674-2006-HPX-Build-Repair-Thread/page4)

[rodbuilder]

1. Change the spark plugs.

2. Properly adjust the idle mixture screw.

3. If it's been sitting for any length of time trash the gas and put a tank of 93 octane and 1/2 can of Seafoam in it.

4. If all that fails take it to a dealer!!!!!!!!!!!

[jergeod]

I have been fighting this problem for the past two months, I have cleaned carb twice with all new gaskets, new plugs, valve adjustment, changed coils, checked for water in the gas, cleaned all electrical connections and lubed. Still had the problem. Can someone tell me what the solenoid in the bottom of the carb bowl does? I took it out and checked it to see if it is working and when I added 12 volt to it the plunger didn't move till I just put slight pressure on it, so I'm thinking it is bad. So now I'm thinking what if I leave it out and use a bolt to plug the hole, WALA this thing runs like it was brand new again. So I put the solenoid in the vise cut off the plunger and put it back in the carb cause the bolt I used was dripping and the thing runs like a clock. Can someone enlighten us on what this solenoid is suppose to be doing?

[Rare1a1]

I have a diesel but my best guess is that's an auto enrichement circuit, or choke.

[jergeod]

It isn't choke that is cable, the enrichment would be my guess too. Hoping someone knows for sure. But it is now running great beings as I cut the plunger off it.

[jergeod]

Update on my little modification, the thing is running like a new machine not seeing any extra fuel usage no bogging at start. Overall runs much better. Haven't replaced that solenoid with a new one and do not think I will the way it is running now. :BG:

[200mph]

jergeod,

I'm not 100% positive, but I believe the solenoid shuts off fuel to the carb when the engine is off (key off)... Appears to be a safety device to prevent fuel from draining into a hot engine and catching fire after the engine is turned off.

[jergeod]

I have no idea haven't searched to find out yet. But I thank you.

[200mph]

Jergeod,

FYI... I searched the Solenoid through JDPARTS.com and is used on several different pieces of equipment including lawnmowers.

If it performs the function as stated in the earlier post of a fuel shutoff valve it correlates with the symptoms you're experiencing as they sound like a lean condition (when throttle is demanded additional fuel is needed or it will bog or even backfire). If the solenoid is removed it basically functions like a carb or years past would without the feature and thus should not cause any operational problems.

You'll have to decide if the safety aspect of the Solenoid in preventing fuel from flooding the engine or possibly migrating to a hot exhaust during key off conditions is worth fixing.

Was voltage available to the solenoid with the key on? This could have been the problem

To test the solenoid a 9v battery (or 12v source) can be used to energize the solenoid. Be aware the plunger typically needs to be slightly depressed to actuate. Note: in its unpowered state the plunger is fully extended and when it is in the carb it is slightly depressed. Slightly depressing the plunger with power to the solenoid should cause it to retract fully.

[jergeod]

Last night I searched at JDparts and all they say is solenoid with no mention of what it is for. To answer your thoughts on this I have no flooding symptoms / problems when key is shut off left to sit 5 min and restarted, as far as roll over I don't use it in any fashion that that would ever happen. Going to stop at JD dealer and see if they know for sure what it does. All I know is it starts better idles better and runs fantastic, this thing has never run this good from day one

[200mph]

An extra step is needed in jdparts.com

Select the where used button and it will show other applications. Searching these other applications it is possible to find more info about it.

[jergeod]

One of the things I did find about it is it cost $179.00, ARE THEY JOKING!