Runs good for about an hour, then needs 15-30 minute rest period

Hi David:
There may be a recommendation in the owners manual.
Depending on how many hours you are running it, I would recommend:
- 1st change including filter after 25 hours (just because there may be some "run in" residue.
- Every 100 hours and at the end of each cutting season. (best not to leave used oil in an engine for long times.

Cheers

their are a few different filters for your rider --these are for the kohler 26 hp motor stores like home depot- lowes- sears- or small engine repair shops carry filters K&N PS-1002 http://www.sears.com/ayp-genuine-ayp-part-578416804-oil-filter-kohler-cou/p-SPM8242278631?redirectType=SKIP_LEVEL http://www.knfilters.com/oil_filter/all/kohler/sv735/26hp

Check the fuel tank cap. It needs to let air into the tank and has a small hole to enable this. Try running the engine with the cap loosely in place to verify this is the cause. If you can't clean it get a new one.

need fuel, spark and air. Make sure air filter is clear. Best way to test this is leave it off while you try to start (or restart??). For spark, easiest way is to spray starter fluid in the carb. If it starts, you have a fuel problem. If you havent lately (or ever?), change the fuel filter.

Yes, adjust your valves.

to be honest the enigne ahas a control that the left side must fire and run before the right starts to fire it sounds to me like you have a fuel issue possibly the carb. is gummed up and dirty.

that engine uses 2 so if you have no spark from either one check your safety switches unplug the harness going to the engine and try then some have a module check for power in

Your fuel octane is GREAT ! Good to hear you are using fresh fuel. Make sure to use Husqvarna HP oil. It makes a difference of the heat generated by the engine.
1) If you can: Do not run the saw dry when cutting. As soon as you have the indication that it is almost dry, stop. Remove the fuel cap to remove pressure in the tank. Allow a 5 minute cool down before refueling.
2) I see your saw is a 2003, you may have debris under the flywheel shrouding restricting air flow: remove the recoil assembly and flywheel cover/shroud under the recoil. (if it has one)
Check to see if debris has gathered around cylinder fins.
Clean with compressed air. The ability for the flywheel to breath means more air to cool the cylinder and lower the overall operating temperature of the engine.
3) Make sure the air filter is clean and area is free of debris.
* Each item may be small, but each one builds on the operating temperature.

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

First check fuel shutoff valve on bottom of carb . Disconnect and remove , clean witn carb cleaner and be sure there is power at wire when the key is on . Also clean carb jets and bowl .....

the float is stuck closed clean the carb and that should take care of the problem. if not you will need a rebuild kit...good luck