Loses power

[Gary E]

Have a BX1880 bought new. Approx 390 hrs. Tractor will run as normal then start losing power, drops RPM and almost stalls. Will vary from 10 mins to 45 mins after mowing.
I have change fuel pump, fuel filters, ALL new fuel lines. Cleaned out the fuel tank.
Tractor never gave any issues until recently when it started this issue. Cannot use/mow as is.
Any advice Is appreciated.

 

[Henro]

Bad vent at the fuel filler cap?

Loosen the cap and see if it makes a difference. Just a WAG…

 

[D2Cat]

Welcome to the forum. The symptoms you describe are almost always fuel related and you've covered about everything simple. One thing comes to mind, fuel tank vent plugged and at some point the fuel being used can not be pumped out because of the vent. Might try running with the fuel cap off, or at lease loose.