slight hanging idle, then slowly stalls out

[60ratrod]

So the dyna s fixed my backfiring and poor running issues, woot and what not. So i took the 650g out for a test run and ran great and idled well for the most part. During the ride, i figured i would stop and see how the idle was doing since the bike by this time had sufficient time to fully warm up. After pulling over i noticed the dwindling idle, which led to stalling out (i wanted to see if it would stabilize or stall). I started it back up and started futzing with the idle adjustment knob, and noticed that even the smallest adjustments caused a hanging idle and eventually dwindle out to a stall. But when the idle would stabilize momentarily before stalling (roughly 1200rpm or so) the oil pressure light would flicker and even come on, but if i applied throttle to maintain a 1500rpm idle the light would go out. Could this be an oil pressure regulator or the Rotella 10w30? I couldn't hear any knocking at any rpmin any gear

But back to the initial issue, what would cause a mild hanging idle after fully warmed that eventually leads to a diminishing idle stall out? Aside from the above issue(s), the bike runs fantastically

 

[tom203]

The oil light stuff is odd- mine goes out during cranking . This thing should idle fine at 1100 rpm and be pumping enough oil to kill light. I suspect the oil sender is a 10 psi unit.
As to diminishing idle, seems that it's losing mixture after warmup- are boots OK, new o-rings at boot/head interface?

While I'm here ,that guy in S. Carolina was having trouble with his dyna install on his 650.

 

[tkent02]

10w30 is too thin. Use the 15w40 Rotella. The 650 is not a roller bearing crank, it needs decent oil pressure to run safely. Adjust the idle high enough so the light doesn't come on, but with the right oil weight it shouldn't be a problem.
As far as the dwindling idle, most likely a good synching of the carbs and adjusting of the mixture screws will usually fix that.

 

[60ratrod]

Hey Tom, i'm going to be writting an install thread for the dyna here in a little while. I didn't think about doing a sync since the carbs were both benched and vacuumed eariler, i think about April/May. Maybe i'll hook my sync gauges back up to see, after getting the 10w30 out

Tkent, i was kinda hoping it was too thin of oil. I know Shelah is a plain bearing motor, i had to open her up over the winter to do the trans.

 

[60ratrod]

Also to add, the manifolds are great, and the o-rings are new about the same time as when i put the motor back in the frame this spring

 

[60ratrod]

Ok, so i got the 10w30 out and poured in the 15w40 i bought last night and did another vacuum sync. At 2000 rpms, i have about 3-4 cmhg (that's the unit of measurement my sync gauges use) of difference between all of the carbs, with #1 being the furthest out of the 4. For what ever reason i couldn't get them any closer than that, especially #1. The other 2 are closer to #3. But now it idles WAY better and i let it run for a while at idle (with my hurricane fan blowing on it of course) and blipped the throttle numerous times and reved it to about 3500rpms a few and no hanging idles, or diminishing idles that eventually stall, well that is until i ran my tank dry. But i refilled and fired back up to let her run a bit longer and still as she should be running. I'm gonna take her back out for another "real world" test run tomorrow after i get off work.

Side note, what order should i be adjusting the butterfly adjusters to get #1 closer?

 

[2BRacing]

Side note, what order should i be adjusting the butterfly adjusters to get #1 closer?

First, the one in the centre between 2 and 3 (this is for carb 2).
Second, the one between 1 and 2 (this is for carb 1).
Third, the one between 3 and 4 (this is for carb 4).
Carb number 3 is the "master".

Adjusting one screw will affect the readings on all the other carbs as well. Follow the sequence a few times in order to get all as close as possible to each other.

 

[60ratrod]

Well instead of riding tonight i decided my sync could be better so i hooked my gauges back up and followed the 2 1 4 pattern. I dunno, i think it's damn near perfect, about 1cmhg difference now. I also re-sync'd sarge, and wow, my supposed throttle shaft issue went right away. I had no idea carbs being out of balance could cause so much hell

 

[2BRacing]

Yes, that is a good result, well done!