KINEKT Bike Suspension Seatpost, XR Lightweight Aluminum Alloy Seat Post for Road, Gravel & Electric Bikes, Rider Weight 80-320 Pounds, Measure Current Seat Post First for Proper Fit

6.4 makes finding a bike that fits difficult. These might help. These examples will let you set the seat back from the seat post. Some are quite long. https://www.amazon.com/gp/aw/d/B0DCG7C89T https://www.amazon.com/WEERAS-Bicycle-Support-SeatPost-Multi-Size/dp/B0C7C72SJY Many of the suspension seat posts will allow you to set the seat back a couple of inches. https://www.amazon.com/Kinekt-Suspension-Seatpost-XR-Lightweight/dp/B09NMX8FK2/ Riser handlebars will help with comfort but it’s probably better to let a bike shop do it. They will be able to easily extend the cables if necessary. The 4-Stroke engine will need an oil change every 25 to 50 hours of operation. Check the manual for what they recommend. Metal engine stands for the 80cc engines are available. If and when this engine wears out you can swap in the A85 by drilling the engine stand to match the 4 stroke engine mount. Or just deltree the 4-Stroke mount entirely and mount the A85 with its native hardware. If you want more power out of the engine you can wash the ethanol out of the fuel. It’s reasonably easy and can buy you an extra ~10% power. (YMMV) Throw some tube protectors like Mr. Tuffy or CNC liners into the tires and put some good quality tube sealant in the tubes. (I don’t recommend using the Tannus armor in fat tire bikes.) The sealant/protector combo makes getting a puncture in your tube a; “I’ll take care of it later.” thing and not a “this is an emergency problem” thing. The tube liners will stop goat head thorns and most glass. The sealant will take care of anything that the tube liners don’t catch. Good luck with it. 🍀