Topic: points dwell and the shy F appearance under the stroboscopeometer cb400f

[Redline it]

i wont go into detail about how to get the f mark to show up in the timing advanced window. although it is for some reason having a tantrum about it. after a couple of good hard riding it started to flatten out a little in power, feels like it sounds when you put your boot over the exhaust. but the new issue is timing the spark from either side if i get it on the 1200 rpm mark, and then the advance marks aren't lining up. would that be spring being weak or the stopper on the advancer? no 2/3 used to vibrate quite a bit, and now it's either vibrating a lot or my eyes are getting that shot. weird thing though. so the cam lobe has a couple of light scratches on it. so i looked at the felt pad and there was a gap 1/16" and it's not creeping out so i opened the pinchers and pushed what was left back in touch with the lobes and added a dab of slick 50 grease to it. and both sets of points were oddly way out of where they normally run. thanks for the input.

ps i picked up a 2000 xr650r a month ago. it rattles so loud i thought it was a rod or crank bearing, hellacious knocking. so i just keep riding it  i've never been on a rocket ship like this is. i tried to find out how far the power would keep developing. i haven't found it. a knock wouldn't or couldn't let that happen would it? 

[BenelliSEI]

Any chance your advanced shaft is bent?

[bryanj]

Advance marks shouldnt line up at 1200 but higher

[KennyRedman]

My advance marks line up at about 2500

[Bodi]

Timing is not critical at low rpm. You just want a late enough spark to avoid knock preignition. There is lots of time for combustion to progress. Yes the mark should be stable and maybe the springs are stretched out and loose at minimum advance, that should be fixed.
But timing is best done at full advance, at higher rpm where the advancer weights are hard against their stops. Set points at the advance marks and accept whatever this leaves you at idle. Unless something is bent, broken, or worn out that should be good. Timing is critical at high power/high rpm.Too much and you risk serious damage. Not enough and power drops a lot.
Get the gaps as close as you can to spec but this is not as critical as timing.

[Redline it]

Timing is not critical at low rpm. You just want a late enough spark to avoid knock preignition. There is lots of time for combustion to progress. Yes the mark should be stable and maybe the springs are stretched out and loose at minimum advance, that should be fixed.
But timing is best done at full advance, at higher rpm where the advancer weights are hard against their stops. Set points at the advance marks and accept whatever this leaves you at idle. Unless something is bent, broken, or worn out that should be good. Timing is critical at high power/high rpm.Too much and you risk serious damage. Not enough and power drops a lot.
Get the gaps as close as you can to spec but this is not as critical as timing.

it could be a bent advancer, setting it at advanced sounds good i'll try that. i did a vacuum sinc on it #1 carb was alot lower than the rest and to check if there was leak in the connection i removed the hose from 1 and used my finger to plug the hole, while running, and i did some checks on it. after getting it close and shutting it off,  oil was dripping out of the exhaust moisture hole. from unbalanced vacuum, so would it still suck oil in the same scenario with excellent rings? maybe even worse, anyways, putting a 3.00-18 6pr shinko on the front, and a 3.50-18 4pr shinko on the rear. is that gonna be a crappy handling combination? i don't really want 6pr. but that's what showed up. the tires on it were 100-90 on the front and 120-90 on the rear dunlap k-591 6pr. they're huge, i almost couldn't get the rear tire off.

[newday777]

"oil was dripping out of the exhaust moisture hole"
That might not be oil. It could be unburnt fuel mixed with oil/exhaust grunge that was stuck to the exhaust walls, making an oil like substance.