JD LA175 running erratic

[Fracture]

So my JD LA 175 ("26 HP" B&S w/ 54" deck) lawn tractor has ~ 60 hrs on it and this year after changing oil, oil filter & air filter, I found it was running irregular. The RPMs are surging up and down mildly and, also not infrequently, it's misfiring.

Following the manual troubleshooting, I then changed the sparks and fuel filter but no change.

At idol it doesn't really run irregular and never misfires, only under load- driving and cutting. Strangely it seams to misfire more when driving down a slope. The power doesn't feel to affected because I only appreciate a very minor perceptible surge or lag in ground speed.

I'm using fuel I stored with "Sta-Bil" over winter and added a "Star Tron" enzyme fuel treatment prior to starting. Can fuel really be a factor?

No problems last year and I ran it monthly through the winter but didn't drive it. Also, it starts just fine.

I'm not sure where to go from here. I'm really hoping I don't have to bring it to the dealer.

Thanks for any help.

Gino

 

[EngineMan]

It maybe running a bit too lean, have you cleaned out the carb..?

 

[Fracture]

Hi EngineMan,

Do you mean with a carb cleaner spray or dis-assembly? I didn't think @ 60 hrs I'd have to tear down the carb yet, but I'll consider any option at this point.

 

[EngineMan]

Hi EngineMan,

Do you mean with a carb cleaner spray or dis-assembly? I didn't think @ 60 hrs I'd have to tear down the carb yet, but I'll consider any option at this point.

It does'nt make any difference if you have 60 or 6 hours on the clock, if you have uncleaned fuel, you ask a question, and I give you an answer, you don't have to do anything with it.

 

[Fracture]

So this really sounds like a fuel problem? If so, how should I clean the carb? Carb cleaner an option, or should I tear down. Sorry EngineMan, I wasn't challenging you, I'm just trying to understand my options and the process. Thanks for your patience to "teach a man to fish" and all that.

Thanx

 

[EngineMan]

Post up all of the numbers that you will find on the B&S engine.

 

[pile81]

Drain the fuel lines, tank.....clean the carb, and possibly sea foam the engine while its runnin to clean up the valves and valve stems.....fuel starts to carmelize after like 30 days, stabil gives you another 15 or so days on that, disregard the label. Old/bad gas kills these small engines and carbs they aren't built like they used to be EPA squeezing down on emissions rules leaning everything out...

 

[Fracture]

Thanx guys,

@EngineMan, Found 2 groups of #'s:

Engraved On head cover: model 44P77; type 0164 B1; code 100222YG

On sticker: model 44P7770164 B1; serial 100222YG 18504

more or less similar but arranged differently.

@pile81, Run w/ covers off the head and valves exposed? Sounds like an accident waiting to happen. If you think it's safe I'll try it. Also what is sea foam?

Thanks again guys

 

[Fracture]

@pile81, sorry for my ignorance.

Looked up sea foam and it looks like you mean for me to spray into carb when running. Is that right? Also I see people say to put in oil and fuel, but mostly the instructions are referring to auto engines. Do you use it like this in your small engines?

 

[EngineMan]

You do need to read #7 again, because I don't think you did...!. do what the member has told you to do, and if it does'nt work come back here. I will look up engine number which is 44P777. and not 44P77


"Run w/ covers off the head and valves exposed?" can't see that line anywhere in #7.