ATC 90 cam chain tensioner

[Pafrig]

Hey, I have a 79' atc 90 that has a rediculously loose cam chain. When I went to adjust it, I first tried taking the cap off, and turning the plug in there clockwise. nothing happened. huh. anways, after some tinkering, i took the left case side off and took a look at the tensioner mechanisim. it looks to me like an *-O- with that astrik being an idler wheel. then theres a spring that turns the device clockwise, pushing the idler into the wheel. the adjuster screw rides up against the dash on the right side, limiting how far the idler is alowwed to tension. The thing that gets me, is that with my adjustment screw all the way out, (no limitation on how far the idler can go clockwise,) the chain still isnt tight enough because theres a little stop that keeps the tensioner from going really far clockwise. I'm really stumped. it looks like it physically can't tighten anymore, yet the chain still slaps around when the engine is ran. help?

[atc350xer]

Could the chain be stretched?

[Pafrig]

maybe, but i doubt it. it still fits on the sprockets tightly.

[Mr_RPM]

are you sure its tightened all the way? mine was jammed and gave that appearance but once unjammed it gave way and tightened fully, but mine may be different. i haven't seen the inside of a 90, just a 110
also maybe someone put the wrong/to long of a cam chain in there.

[atctim]

I am going to say what atc350xer said - the chain is stretched. Over the years this happens. New timing chains for these little guys are cheap. I have replaced several chains on these little models. They are ALWAYS stretched!