522XI Running Poorly - Help Needed

[stevebo-(Moderator) 8,532]

Hello all.

 

I have a 522xi that has be stumped. Picked up non running. It will only run on choke and not that good....Here is what I did to it. 

 

1. Checked fuel to ensure that it flows good from tank

2. Replaced all fuel lines including vac line to fuel pump

3. Changed filter

4. Changed fuel pump

5. Cleaned car and set mixture to spec (1 1/2 turns)

6. Tried a proven carb on it from another 520xi I own

7. Swapped plugs with another one I own

8. Checked spark on both plugs and good

9. Filled with good gas

 

I am at a loss here. Will ONLY run with choke fully on. Battery is weak but gets it to start. Could the battery be the issue? Any advise would be appreciated. Thanks!!

[WHX?? 51,745]

That is bizzare. Sounds you covered all the fuel related issues and that it is starved for fuel. Check the intake manifold for leakage? Not enough vacuum to draw fuel? 

Edited June 15, 2020 by WHX24

[stevebo-(Moderator) 8,532]

I did spray wd at the base of the carb and no change. The base gasket is used but could need replacing?

[squonk 43,819]

My first thought is some kind of vacuum leak. Air leaking in leans out the cylinder mixture so you have to cut off the incoming air at the carb with the choke to get the mixture close. Also closing choke increases engine vacuum so it can pull fuel out of carb

 

[squonk 43,819]

Does this engine have any kind of intake manifold?

[WHX?? 51,745]

Should be a Command CH with a V looking manifold, block gaskets but guessing you sprayed them. Possible breather issue? 

[lynnmor 7,817]

Maybe some junk in the fuel lines plugged both carburetors, I would make another attempt at cleaning.

[squonk 43,819]

Any vacuum hoses on this beast?  ( I got a $50 tip one day due to a hole in one of them critters) 

[stevebo-(Moderator) 8,532]

It has an intake with two runners. Could be there but man this is kicking my tail. Tried two new plugs and all new fresh gas again

[stevebo-(Moderator) 8,532]

I think the only vacuum is the one to the fuel pump which I replaced

[Shynon 7,482]

Steve there is a little brearher tab that I have heard can break. Thus having no crank case vacuum.  Pics from my 518XI 

[SylvanLakeWH 28,400]

Do those have gas cap vents that typically plug like the older ones? Just a thought...

[JoeM 8,345]

I am interested because my daughters 520xi will be running great, then shuts off like it ran out of fuel. I changed some of the fuel lines, filter and the fuel pump. I can only start it back up and run it on choke. After a few minutes, it runs fine. Good gas, good flow from the tank, pump seems to be putting out. I ran the engine with the pump discharge into a plastic bottle, seems, okay. 

I did notice when this problem happens there is very little fuel in the filter.?? typically it is about half full. 

Just about ready to install an electric fuel pump. 

Trouble is, I got to cut grass for about 20 minutes to get it good and hot before the problem shows up. Might install the pump and go for a burn this weekend.

 

[gwest_ca-(File Mod) 11,482]

This service bulletin includes fuel tank vent.

Garry

[shallowwatersailor 3,214]

Two things to try - and both might not work. Jumper the seat switch out, and try a different battery. I think I had trouble one time with either my 518xi or 520xi with the way it ran. Swapped batteries and it ran fine.

[JoeM 8,345]

9 hours ago, shallowwatersailor said:

Jumper the seat switch out

My 520 LXI seat switch was bad. At times it would have high resistance and the engine would start "breaking up". I twas random problem.

These machines are still a beast

9 hours ago, gwest_ca said:

fuel tank vent

going to check that today

[JoeM 8,345]

15 hours ago, gwest_ca said:

service bulletin

Checked the xi vent today, definitely an issue. 

Pics are how it was when I removed the seat pan. That hose has never been in the correct position.

Also, someone cut off the seat switch wiring plug, twisted the wires together and tape. 

 

[stevebo-(Moderator) 8,532]

On 6/15/2020 at 8:28 PM, TractorJunkie said:

I am interested because my daughters 520xi will be running great, then shuts off like it ran out of fuel. I changed some of the fuel lines, filter and the fuel pump. I can only start it back up and run it on choke. After a few minutes, it runs fine. Good gas, good flow from the tank, pump seems to be putting out. I ran the engine with the pump discharge into a plastic bottle, seems, okay. 

I did notice when this problem happens there is very little fuel in the filter.?? typically it is about half full. 

Just about ready to install an electric fuel pump. 

Trouble is, I got to cut grass for about 20 minutes to get it good and hot before the problem shows up. Might install the pump and go for a burn this weekend.

 

That is what happens with my neighbors 522xi

On 6/15/2020 at 8:44 PM, shallowwatersailor said:

Two things to try - and both might not work. Jumper the seat switch out, and try a different battery. I think I had trouble one time with either my 518xi or 520xi with the way it ran. Swapped batteries and it ran fine.

 

 

[JoeM 8,345]

Glued those lines down in the groves and blew the vent line out with air, cut 1/2 and acre no issues. ?? will see.

[stevebo-(Moderator) 8,532]

Anyone here know if I have to pull the motor in order to get to the intake gaskets? I have not looked hard but at quick look it may not be possible to remove tins on top to access in the tractor.

[Shynon 7,482]

You may  be able to move the plate between engine and steering to access the flywheel cover and move it toward the steering shaft. To get to the intake bolts.

[stevebo-(Moderator) 8,532]

Thanks pal. Not looking forward to this job