Looking for help

HelpNeed3d

Member
Joined
May 30, 2023
Threads
1
Messages
10
I was given a Husqvarna RZ4619 zero turn mower from a friend who said it hadn't been used in 2 years and had been kept outdoors. The mower has a Briggs and Stratton 19hp intek, single cylinder engine on it.

I have done the following;

Oil/oil filter change
changed spark plug
replaced fuel lines, filter, and pump
replaced carburetor

The engine runs great while sitting idle (both at lowest speed and highest speed). However, As soon as the engine is placed under a load, either by engaging the blades or by driving forward at full speed, the engine sputters then evens out, then sputters and evens out about every 10 seconds or so.

One side note, the new carburetor that I put on does not have the air adjustment screw like the old one had. Could that cause this issue? If not, any other suggestions on what to check?

Thanks!
 

slomo

Lawn Addict
Joined
Jul 14, 2019
Threads
76
Messages
4,713
the new carburetor that I put on does not have the air adjustment screw like the old one had.
What do you think this is telling you? Wrong carb right?

Was this an OEM Briggs carb? Doesn't sound like it. Going to have to boil clean out the Briggs carb. Check for vacuum leaks.

Here's another one to add to your bag of tricks. Dump and flush out the fuel tank.

Valve adjustment time couldn't hurt.

Is it over-heating causing poor power output? Are the cooling fins clean? Take pictures of the block and cooling fins. Post them up here.
 

HelpNeed3d

Member
Joined
May 30, 2023
Threads
1
Messages
10
What do you think this is telling you? Wrong carb right?

Was this an OEM Briggs carb? Doesn't sound like it. Going to have to boil clean out the Briggs carb. Check for vacuum leaks.

Here's another one to add to your bag of tricks. Dump and flush out the fuel tank.

Valve adjustment time couldn't hurt.

Is it over-heating causing poor power output? Are the cooling fins clean? Take pictures of the block and cooling fins. Post them up here.

The new carburetor is after market. I tried finding information before i bought it on whether you can replace a carb with the air mix screw with a carb that doesn't have it. I couldn't find anything. Other than the air mix screw, the carb is identical. So are you saying the carburetor is likely the issue? I will try cleaning the old one and putting it back on to see if that makes a difference.

Wouldn't a vacuum leak cause it to surge even at idling?

Fuel tank was flushed, cleaned and new fuel added when I replaced the fuel lines.

I have not messed with the valves.

I'm sure the fins are not squeeky clean, the mower has been sitting outside, uncovered, for 2 years. I did check them for wasp nests, critters etc. but haven't given them a good cleaning. I don't have a photo right now. I can post one later when I get home.
 

slomo

Lawn Addict
Joined
Jul 14, 2019
Threads
76
Messages
4,713
Wouldn't a vacuum leak cause it to surge even at idling?
Depends on how bad the leak might be.

I HOPE it hasn't sit for 2 years with Ethanol fuel in the carb. That stuff is like acid eating away corroding the aluminum.

Fuel tank was flushed, cleaned and new fuel added when I replaced the fuel lines.
Good man.
I have not messed with the valves.
Might be worth a look. You are loosing power. Either air/fuel related or some valves might be out of spec.

I'm sure the fins are not squeeky clean, the mower has been sitting outside, uncovered, for 2 years. I did check them for wasp nests, critters etc. but haven't given them a good cleaning. I don't have a photo right now. I can post one later when I get home.
I'm holding you to this LOL. :p(y)
 

HelpNeed3d

Member
Joined
May 30, 2023
Threads
1
Messages
10
Yes, it definitely sat with fuel in it. That’s why I went ahead and just replaced everything from tank output to the carburetor.

I’m trying to take pictures, but it keeps telling me the files are too large. I’ll keep trying. But the fins are not bad, obviously a little corroded but not super dirty.
 

Forest#2

Well-Known Member
Joined
Apr 17, 2022
Threads
0
Messages
364
So it was doing the exact same thing before you started replacing things??????
 

slomo

Lawn Addict
Joined
Jul 14, 2019
Threads
76
Messages
4,713
Yes, it definitely sat with fuel in it. That’s why I went ahead and just replaced everything from tank output to the carburetor.

I’m trying to take pictures, but it keeps telling me the files are too large. I’ll keep trying. But the fins are not bad, obviously a little corroded but not super dirty.
Turn the cam resolution down in the phone or resize in Windoze.
 

HelpNeed3d

Member
Joined
May 30, 2023
Threads
1
Messages
10
Yes, it definitely sat with fuel in it. That’s why I went ahead and just replaced everything from tank output to the carburetor.

mom trying to take pictures, but it keeps telling me the files are too large. I’ll keep trying. But the fins are not bad, obviously a little corroded but not super dirty.
So it was doing the exact same thing before you started replacing things??????
No, it had been sitting for 2 years with gas in it before I got it. It wouldn’t start at all, so I just went ahead and replaced all those things to get it going.
 

HelpNeed3d

Member
Joined
May 30, 2023
Threads
1
Messages
10
What is the Mb limit for files?
I think I got it. Hopefully these attach. Wanted to post a video also of what the engine is doing, but it was WAY to big.
 

Attachments

  • IMG_5586.jpeg
    IMG_5586.jpeg
    433.1 KB · Views: 126
  • IMG_5590.jpeg
    IMG_5590.jpeg
    295.8 KB · Views: 117
Last edited:
Top