if it's new & under warranty take it in for repair otherwise warranty will be void if you mess it up trying to repair
At least for Honda,
it is not possible to 'void' your Honda warranty; the warranty is a legal document/agreement between the owner and Honda and it can't be 'voided' by Honda for any reason, including for mowers a customer has modified or done their own service work.
What CAN happen is if a customer does repairs, or makes modifications to their mower, and
those changes cause some failure, Honda may decline to pay for a repair. So if a customer pulls off the carb and can't get it on properly, that's not a warranty issue for Honda to pay to repair. If a customer leaves fuel in the tank for 2 years and it decays, making the mower hard to start, that's also not a warranty item.
But, if the customer does his own oil change, air filter and spark plug, with non-Honda parts, but then the right front adjuster breaks into parts, it would be obvious the two are NOT related, so the broken adjuster WOULD be covered under warranty.