Hello, yesterday I tensioned the timing chain on my YUKI SM 125 (same engine as Suzuki GN 125, 157FMI). I tensioned it probably wrong, without seting the piston in any position, even thou the manual doesnt say to put it in to any position.

Today I went on a ride and after a while it started to feel like if there was no fuel/no spark, started squeking, and then locked up the rear wheel. I stopped, and after a minute I started it back up and it acted as if nothing happened. It happened about 2 more times before I decided to head back home after about 2 miles/3 km. I rode home with very little to no throttle and pulling in the clutch as much as possible.

I thought it could be happening because of too much tension on the timing chain, so I completely removed it and reajusted it 1 milimeter back and put it back in.

Then I went on a test ride but It happened again, no power, squeking and locked up rear wheel.

I dont know where to start looking for solutions, I dont think it has anything to do with fuel/air. The only thing I did was tighten the cam chain and put a bigger chain sprocket in the front (on the engine).

Thank you for any thoughts on the problem.

Hey, I got a chinese bike YUKI 125 SM, it should have the same engine as Suzuki GN 125. I am hearing some noises from the engine that i think are because of a loose cam chain. There is this type of cam chain tensioner. I have read from a very random source That I should just loosen the bolt and retighten it and it should be tensioned. Can someone reasure me that this is how this tensioner works or tell me what to do instead?

LSS: how do I tension this cam chain tensioner?

I am 16 and got my A1 license 3 months ago. I was offroading a chinese dirtbike for about a year before that. Got my YZF 125, put on some new Dunlop tires and bought a cheap Pakistani leather suit. Today I decided to get at least a small viewable result of my riding. Do you guys think that my lean angle is good for now? It looks like Im better at leaning right turns. Thanks for any feedback.