All in all this is a great product and I do recommend it from the stock chain tensioner that comes with your motorized engine bike kit.

I do wish the spring had more tension to it and that the screws/bolts weren't made of aluminum because I have had one snap on me.

Also for those who have higher cc engines or torque make sure your chain is tight before installation because when you do engage your clutch even slowly at high speeds the bottom of the Chain fully pulls on the tension wheel and if the chain is not tight enough will cause slack in the upper part of chain and cause your chain to lock up in your housing and will bring your tires to a dead stop or if your lucky will break your chain either way it would not be safe or fun

The installation process is very simple even though it doesn't come with any instructions it goes as follows:

Step 1
The set up process is very simple I have found it easier to connect one side of the spring to the curved side of the mounting plate where the 2 small holes are (The top hole would have more tension then the bottom one)
Step 2
Out of the 5 screws/bolts and 2 locking nuts and 2 washers that come with the tensioner use ONLY the small screw/bolt and locking nut to attach the tensioner arm to the mounting plate
Step 3
Remove original screw from the housing cover and place tensioner plate over housing cover and use the 3 Similar screws/bolts to mount the tensioner plate on top of the housing cover and tighten in new screws
Step 4
Take the biggest screw/bolt and add 1 washer then the chain tensioner wheel then the other washer then locking nut to any of the 4 large holes on the tensioner arm
(IMPORTANT MAKE SURE THERE IS A WASHER ON BOTH SIDES ON THE TENSIONER WHEEL)
Step 4
Connect spring from tensioner plate to tensioner arm

there are better out there but not for the price, and for an extra 10 bucks you can make it just as good as the better ones

I'm an experienced bike enthusiast and have built multiple gas engine bicycles. This product is always my 1st and most important upgrade to any gas bike setup. It keeps constant tension on your chain without fail if setup is done properly. It's important toTake time and care when tightening the nut that hold the swing arm to the main body of the part and also the nut and bolt that run through the idler wheel. You want as little slop or play as possible but make sure that they move and spin freely. Gas engine bicycles can travel 30+ mph. Chain failure at those speeds could be very dangerous. I trust this part on all of my bikes. Take your time with setup and enjoy.

Had to modify it and add a washer works alright

I haven't been able getj one on anything but two stroke moto
bad luck with these motors. I though theCheck the sizes. These were for a little girls sneakers and they didn't even make it to the top of the leaving holes Check the sizes. These were for a little girls sneakers and they didn't even make it to the top of the leaving holes stopped
Aww