First post so be gentle 
I am helping my son install an engine kit of his bike. He wanted the kit for Xmas, I told him it wasnt going to fit the bike he had but he insisted it would (I knew it wouldnt) so we bought it anyway and it didnt fit. Ended up picking him up a cheap single speed from Walmart to install the kit on.
Ive kind of run into a quandary on the wheels.
The bike comes with a flip flop hub. It didnt really dawn on me that I wouldnt be able to get the sprocket over the fixie gear when I bought the bike so now Im in a position of trying to make it work.
I originally thought Id use the fixie gear as my drive gear but I cant seem to find a good setup that works with the included tensioner and gets me anywhere near where I need to be for the chain length. Ive tried orienting it multiple ways and just cant seem to find a way to make it work.
So.. I need to either have the rear hub changed out, get some new sort of tensioner or a new wheelset. These are 700c wheels so I really havent found much other than a wheelset on one of the motorized bike sites that has a flip flop hub so I dont see how that is going to do me any good unless there is some kind of adapter I havent run across yet.
Im pretty handy with bikes.. I have built multiple road bikes, do my own repairs, etc so I know my way around bike parts but I dont build wheels. Its pretty much the only thing I cant do with a bike. Just never bothered to learn because I either bought them prebuilt or had a local builder do it.
Any advice anyone can give would be hugely appreciated.

I am helping my son install an engine kit of his bike. He wanted the kit for Xmas, I told him it wasnt going to fit the bike he had but he insisted it would (I knew it wouldnt) so we bought it anyway and it didnt fit. Ended up picking him up a cheap single speed from Walmart to install the kit on.
Ive kind of run into a quandary on the wheels.
The bike comes with a flip flop hub. It didnt really dawn on me that I wouldnt be able to get the sprocket over the fixie gear when I bought the bike so now Im in a position of trying to make it work.
I originally thought Id use the fixie gear as my drive gear but I cant seem to find a good setup that works with the included tensioner and gets me anywhere near where I need to be for the chain length. Ive tried orienting it multiple ways and just cant seem to find a way to make it work.
So.. I need to either have the rear hub changed out, get some new sort of tensioner or a new wheelset. These are 700c wheels so I really havent found much other than a wheelset on one of the motorized bike sites that has a flip flop hub so I dont see how that is going to do me any good unless there is some kind of adapter I havent run across yet.
Im pretty handy with bikes.. I have built multiple road bikes, do my own repairs, etc so I know my way around bike parts but I dont build wheels. Its pretty much the only thing I cant do with a bike. Just never bothered to learn because I either bought them prebuilt or had a local builder do it.
Any advice anyone can give would be hugely appreciated.