Engine surging only when pto is engaged? husqvarna briggs intek

[tsvoma]

Just got a fixer upper 2006 husqvarna yth 2454t with engine Briggs and Stratton 24 hp intek vtwin model number 445677. So I've replaced the spark plugs, oil and filter, fuel filter, air filter and the carb. Mower runs great until I engage pto which then it does this rpm up and down thing which seems to get better as it gets warmer. I've emptied the fuel tank and put in fresh gas, blown out the fuel line with an air hose all the way from tank to carb, set the valves, checked hoses for leaks and set the governor. Is this just a "this motor" kind of thing or what am I missing. Any thoughts would be appreciated! Running the choke at around half pulled fixes the problem so I'm assuming some fuel issue I'm overlooking or not looking at good enough

Tried to get a video of it you can kind of hear what I'm talking about

https://flic.kr/p/2oFXXXf

 

[StarTech]

Just which of the 445677 engine is it?

 

[Scrubcadet10]

i would GUESS an obstructed main jet.
answer star techs question so we know what we are working with exactly.

 

[tsvoma]

Just which of the 445677 engine is it?

View attachment 64936

445677-0413-e1

 

[tsvoma]

i would GUESS an obstructed main jet.
answer star techs question so we know what we are working with exactly.

Its a brand new carb, just put on the other day, its 445677-0413-e1

 

[bertsmobile1]

Firstly new does not mean correct or even good, particularly if it was bought from "Mr Cheap Cheap For You" on Amazon or Ebay
Next question is how long does it do it for ?
A minute or so is fine all the time is a problem .
Mower engine run on the idle jet until you put a reasonable load on it when the main jet kicks in
So your problem is with the main jet , fuel supply , or governor
If it only does it for a minute then it could be the anti-hysteresis spring ( if fitted ) allowing slop in the throttle wire to cause the engine to surge .

 

[Tiger Small Engine]

Firstly new does not mean correct or even good, particularly if it was bought from "Mr Cheap Cheap For You" on Amazon or Ebay
Next question is how long does it do it for ?
A minute or so is fine all the time is a problem .
Mower engine run on the idle jet until you put a reasonable load on it when the main jet kicks in
So your problem is with the main jet , fuel supply , or governor
If it only does it for a minute then it could be the anti-hysteresis spring ( if fitted ) allowing slop in the throttle wire to cause the engine to surge .

Hopefully you did not throw OEM carburetor away. Clean it thoroughly, reinstall, and see if surge under load is present or not, then let us know.

 

[StarTech]

What is being describe is a lean burn issue .

Yes the OP probably put on one those $35 carburetors as the OEM are between $188 and $203 list depending which one he needed,

The Nikki twin barrel is one of the easiest carburetors to repair when you know what you are doing. There are even rebuild kit on eBay that include the main jets o-rings which the OEM kits do not have. Just got to be careful not to lose or mix up the main jets.

 

[tsvoma]

Firstly new does not mean correct or even good, particularly if it was bought from "Mr Cheap Cheap For You" on Amazon or Ebay
Next question is how long does it do it for ?
A minute or so is fine all the time is a problem .
Mower engine run on the idle jet until you put a reasonable load on it when the main jet kicks in
So your problem is with the main jet , fuel supply , or governor
If it only does it for a minute then it could be the anti-hysteresis spring ( if fitted ) allowing slop in the throttle wire to cause the engine to surge .

Is there a proper way to test those 3 things you listed further to narrow it down more? Which spring would it be if it was fitted with it?

 

[tsvoma]

Alright so firstly yes it is a 30$ amazon carb lol when I first got it it was backfiring horribly so I did the basics plugs all filters to see if that would be enough, wasn't so I went to the carb cleaned it (I'm no expert at carbs) noticed that the fuel solenoids little nipple thing was sheered off but put back on regardless and same problem. Looked up the solenoid to replace it was 15$ I believe so instead I just got the whole carb with solenoid and gaskets for 30$. This carb fixed the back firing issue but brought on the surging, unsure if it was surging before. Now today I went back to it to see if I could get more info for you guys. On first start up it surged with pto off so I went up and down with the throttle control no surging on low and surging on high after going up and down with the control about 4 times the surging went away, went out and tried with the pto on and it didnt surge enough for me to notice it. Let it sit for about 10 mins and tried again, this time on start up no surging turn pto on and it surged for about 1-2 mins and went away. With that info what would you guys recommend my next step being?

Just want to take a second to thank everyone for the replies and input. New to forums and the reason I bought this mower was to broaden my knowledge a little bit about mowers/small engines, figured it would be a fun and worthwhile skill to develop. My current knowledge isn't very vast but I know what most things are and what they do and how they do it.