X530 Issue Troubleshooting Help

[ubelongoutside]

I have an X530 I've had for about 2 years. Late last season it started having an issue where it will stutter when I engage the blades at full throttle. Usually this happens when I've had to stop the blades to move something or back up without pulling up on the engagement lever, then go to restart the blades.

It almost sounds like its backfiring. It will go on for about 5 seconds and then resume normal operation. I figured it was a fuel flow issue, but then I noticed that it doesn't happen when I do it at half or less throttle, then go to full throttle after they're engaged.

I've had some other issues I've fixed and things I've tried so far that I thought could be contributing, but the issue remains. So far I've

had an ignition coil go out and replaced

found my choke lever wasn't returning to the open position, but fixed that too

gapped and replaced plugs

Any thoughts on other causes?

 

[Spindifferent]

Could it be related to the mower blade drive belts or perhaps the belt tensioner? Are the belts in good condition and clean?

Also, have the mower blade spindles been lubricated?

Just wondering if the engagement of the belts/blades at full throttle somehow impacts the engine to cause the sounds whereas the engine seems to work fine at lower speeds...

Let us know what you find out and good luck!

 

[Roadworthy]

You say you replaced plugs, plural. Are you sure both cylinders are firing and running? Your symptoms sound like my Craftsman mower when one cylinder wasn't working.

 

[ubelongoutside]

You say you replaced plugs, plural. Are you sure both cylinders are firing and running? Your symptoms sound like my Craftsman mower when one cylinder wasn't working.

Yes, I replaced both. I presume both are working normally as other than this issue the engine runs smoothly. When I suspected the coil I tested both and one clearly wasn't making the test light come on, and the tractor wouldn't start. I replaced it and it started right up.

 

[oldnslo]

Can you slowly apply the choke to see if it runs any better When it is running rough? Might help point towards fuel vs spark issue.

 

[beenthere]

Check that both cylinders are firing when this "stutter" happens. Think roadworthy has a point.

Pull one of the spark plug wires off and see if one or the other is not firing. Let us know so we can get past this point and move to the next for you.

 

[ruffdog]

Can you slowly apply the choke to see if it runs any better When it is running rough? Might help point towards fuel vs spark issue.

A stutter may happen when starting a mower deck and is caused by a lean fuel condition. Agree^^, test this by having the choke partly pulled when turning the deck on. If it takes care of the stutter, there may be a little debris in the main jet circuit that is causing the problem.

 

[ubelongoutside]

I'll try the choke idea as the problem started about the time I found out I had a sticky choke. I fixed the sticky choke and the stuttering started.

If that's the case I'll have to pull the carb and clean it up.

Thanks all. I'll update next time I cut the grass.

 

[ubelongoutside]

Check that both cylinders are firing when this "stutter" happens. Think roadworthy has a point.

Pull one of the spark plug wires off and see if one or the other is not firing. Let us know so we can get past this point and move to the next for you.

I suppose I could get a second test light and have one on each cylinder too.

I'm thinking the lean fuel idea though might be the culprit as this started when I realized the choke was sticking closed and fixed that.

 

[tomplum]

The little node light testers aren't worth much. The light with about anything. Two barrel or single carb?

 

[ubelongoutside]

Single carb

 

[ubelongoutside]

Little update to my woes.

I tried the choke when engaging the blades and that didn't make much difference. (More on that in a minute)

I began to notice a stutter more during normal operation so I decided to check the coils again. Lo and behold now the other coil wasn't firing. So off to the parts counter I went for another coil.

Now we're firing on both cylinders and I'm ready to mow. Only now when I get up to full throttle I'm getting puffs of smoke (smells like unburned fuel) and if I commence cutting I'm really bogging down and losing power.

So I decide I better take a look at the carb. I get it out of there and where the choke valve should be is a melted looking piece of plastic. So at the very least I've been running for some time with no choke even though I thought I was giving it choke.

Anyone ever try to replace just the choke valve or am I looking at a whole new carb?

***EDIT BELOW***

Well my coffee kicked in while I was looking at the schematics of the carb and while I was wondering where the heck the old butterfly valve went as all I had in the choke end of the carb body was a melted strip of plastic.

Then I recalled when I took off the metal air intake piece on the front of the carb there was a piece of metal in the throat of it that looked like some sort of baffle plate. Out to the barn I went and there's my butterfly valved lodged in the air intake. I'm guessing that backfiring I was having before must have blown it off the plastic rod, lodging it there, and also melting the plastic rod.

So rather than no choke, I've been running full choke as the butterfly was lodged in the intake in what would be a closed position.

Guess it's back off to the parts counter...

 

[Runner]

"It almost sounds like its backfiring. It will go on for about 5 seconds and then resume normal operation. I figured it was a fuel flow issue, but then I noticed that it doesn't happen when I do it at half or less throttle, then go to full throttle after they're engaged."

The manuals for both of my JD machines (1989 185 and 2007 2520) say to engage the PTO at 1/4 throttle and 1500 RPM, respectively, then advance to full throttle. So, if that works, why not do it? What does your manual say?

The manual for my new Cub Cadet ZTR says go to full throttle and engage the PTO, which makes me cringe after doing it the other way for years, but if I try to engage with less than about 3/4 throttle, it sounds like it's going to just about kill the engine, so close to full-throttle engagement is probably about right for that machine.

 

[tomplum]

When you get this re assembled, verify that your choke control cable isn't travelling too far and putting stress on the choke shaft.

 

[Richard001]

Little update to my woes.

I tried the choke when engaging the blades and that didn't make much difference. (More on that in a minute)

I began to notice a stutter more during normal operation so I decided to check the coils again. Lo and behold now the other coil wasn't firing. So off to the parts counter I went for another coil.

Now we're firing on both cylinders and I'm ready to mow. Only now when I get up to full throttle I'm getting puffs of smoke (smells like unburned fuel) and if I commence cutting I'm really bogging down and losing power.

So I decide I better take a look at the carb. I get it out of there and where the choke valve should be is a melted looking piece of plastic. So at the very least I've been running for some time with no choke even though I thought I was giving it choke.

Anyone ever try to replace just the choke valve or am I looking at a whole new carb?

***EDIT BELOW***

Well my coffee kicked in while I was looking at the schematics of the carb and while I was wondering where the heck the old butterfly valve went as all I had in the choke end of the carb body was a melted strip of plastic.

Then I recalled when I took off the metal air intake piece on the front of the carb there was a piece of metal in the throat of it that looked like some sort of baffle plate. Out to the barn I went and there's my butterfly valved lodged in the air intake. I'm guessing that backfiring I was having before must have blown it off the plastic rod, lodging it there, and also melting the plastic rod.

So rather than no choke, I've been running full choke as the butterfly was lodged in the intake in what would be a closed position.

Guess it's back off to the parts counter...View attachment 872790

Ah yes, plastic parts on a ICE engine, what could go wrong ?