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  • Replies: 32
GV125C 2012
  • Both Plugs = Slightly overheating… (((With oily deposits on threads????)))
  • Front = leaning out at high throttle
  • Rear = leaning out too but seems to do better than front.
  • Both Plugs = idling OK. (Assumes mixture is 2.5 front and 2.75 rear using size 15 Pilot Jets) but see next bullet point….
  • The carb needs to have its jet needle at a richer setting as the white cones need to be brown after full throttle runs.
  • Mixture screw will have less effect once the carb slides & main jets take over at past 4k revs. BUT it does have an effect during gear changes as bike momentarily lowers revs or coasting while rider carefully disengages/engages clutch to change gears. The carb slides then lift off again.

That oily stuff is copper grease thanks to my uncle. I know it’s not always needed but Me and my uncle had a bit of a fight getting the old plugs out so when i started on the sprocket he plopped them in. It may actually be overheating worse, there’s only 160-180 miles on those plugs.

I’ll be pulling the carbs off when I get my cleaning liquid for the ultrasonic. I’ll leave the settings as what they were, do a couple of full throttle runs and see how much of an improvement. I fully expect i’ll have to clean the carbs two or three times to get them right, they were sat a LONG time.

I’ll drain the tank and have a look over the tank and tap again. When I fitted it (it is new) flow seemed OK but it was cheap and i’m sure that the most expensive stuff starts cheap lol.

I’m going to do a guide for a few things, I like making documentation. I will take some photos of the airbox when it comes off. I’m really trying to mentally prepare myself for it, i’m not quite ready yet to allocate a day to it.

As for cam chain noise it doesn’t actually get worse or better, it’s consistent. really I was just wondering if it sounded ok.
I do have a suspicion the clutch is on it’s way out.  I believe it’s the original and the biting point seems to like to wander. it also seems to stuggle to disengage some times. Maybe the oil i put in before I started work is just rubbish (Motul 5100 semi 10/40 i think).

The heads get a little more clattery when hot but it doesn’t seem to get worse under revs. I’ll use the screwdriver trick to listen to the tensioners. The video was the bike when it was hot/hot ish.

Thanks again.