First, take it off and make sure the idler spins freely on the axle. You need a better system, but here's a temporary fix - Take a toothpick or something and measure the depth of the hole. Measure how much screw sticks out the back of the hole and subtract from the hole depth. Cut a piece of plastic rod, or even soft metal rod (aluminium, brass, etc) to a length where it can be dropped in the hole to act as a stop. When the screw hits the rod it bottoms out, and will prevent the wheel from tightening. This is a temporary fix and it can be easy to strip out the threads for the screw, so take care. It will take several length adjustments to get the length of the rod right, and you really have to be careful. The best bet is to order a henntec
https://etoarmor.com/?product=henntec-i ... hl-tiger-1
I'm not sure the stock idlers fit the henntec. I've used their stuff before and had to machine parts to finish the job. Where are you, again? If you're stateside I have plenty Tiger idlers so we can get you hooked up for just the postage, usually 8 bucks, tops, to anywhere with a US zip code. So go ahead, tell me you're in the UK.
But seriously, if you want to do it right, get idler adjust.
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