B&S Inteck 18hp single hunts

[Freezzman]

B&S Inteck 18hp single cyl hunts seems to run OK for 10 -15 minutes then aggressively hunts .
New Gas, tank clean
New carb and filter
New Plug
Checked gas cap for venting (OK)
set governor and replaced spring (set Static adj) Ides fine max rpm sounds OK
Happens when I use the tractor for lawn fertilizing with a trailer tank (small) and sometimes mowing
If I engage the blades RPM's seen to level out momentarily when spraying
Thanks
Freezzman

 

[mechanic mark]

18 HP B&S INTEK ENGINE HUNTS - Google Search

 

[bertsmobile1]

Hunting is usually because the engine is not getting enough fuel to maintain full speed
So either not enough fuel getting to the carb
Carb not adding enough fuel to the air
Air entering after the emulsion tube in the carb

When presented with this my first step is to run the mower from an external fuel tank plugged directly into the carb
Problem goes away = fuel supply
Problem remains then remove the blower housing and saturate the carb & manifold with liquid WD 40 ( not from a pressure can ) while slowly working the governor arm to accelerate & decelerate the engine.
An air leak will cause the engine to revs to change and blow a lot of white smoke
Neither of the above make any difference only leaves the carb so it comes off for a proper deep clean .

 

[Freezzman]

18 HP B&S INTEK ENGINE HUNTS - Google Search

Hi Mark thanks for the video. Unfortunately if I have seen the right video the carb is fine.clicking on the link it was about using a piece of wire from a brush to clean of the jet tree .