Throttle Body

[JamesW]

If you adjust both TB brass screws out from fully seated by exactly 1 turn then adjust the throttle body stop screws, the ones you're not supposed to adjust ever, counter clock wise  to fully close the TB plates will the engine still idle albeit very slowly?  This assumes that the engine is fully warmed up first.

[dirtrider]

1 minute ago, JamesW said:

If you adjust both TB brass screws out from fully seated by exactly 1 turn then adjust the throttle body stop screws, the ones you're not supposed to adjust ever, counter clock wise  to fully close the TB plates will the engine still idle albeit very slowly?  This assumes that the engine is fully warmed up first.

Evening James

 

Maybe, depends on how much wear on  the throttle plate sides & how much air leakage at the throttle shafts,  how much fuel is being injected, & how much  engine friction at idle. 

 

On an 1100 with the CCP removed (it might just go rich enough to just stay running). 

[JamesW]

I'll give it a try when my new battery gets here.  My 1100 doesn't have an actual CCP but if I recall it is hard wired for what is a yellow CCP.  What I think would be a good procedure and easier than the ages old now zero-zero TB adjustment would be to balance the TBs at idle with the brass screws and the throttle plates closed then simply adjust the throttle plate stop screws CW in small increments until the desired idle speed is achieved with the TBs in sync at this point.  Then just check the TPS sensor voltage to make sure it's within spec (adjust if necessary) and you're finished.  If one turn out from idle doesn't allow enough air to bypass the plates then maybe go 1-1/4 turns out from seated with the brass screws.  

 

This lockdown is making me nuts!

[JamesW]

New Yuasa AGM battery installed and TB adjustment completed with good results.  First I went on a 30 mile ride to warm up the bike.  I found that turning the brass screws (air bypass adjustment) out one turn wasn't enough to maintain idle so turned out from seated 2 turns which resulted in a 400 RPM idle and only required minimal adjustment to attain balance going side to side in small increments.  Next I adjusted each throttle plate adjust screw CW going side to side in small increments while maintaining balance on the Harmonizer until idle reached the desired 1150 RPM.  I checked the TPS idle voltage which was 0.375 VDC which supposedly is in spec (0.370 - 0.400).  I'm not sure where this TPS voltage spec came from or if it is correct but all seems well and the bike goes into closed loop as it should when the engine oil temp reaches 5 bars as it always has.  Bike runs great with minimal vibration at speed or at idle.  So for me I'm done with the more cumbersome procedures ( zero-zero or after zero-zero) as discussed in past threads at length.  

 

I actually came up with this method after reading about and performing a very similar procedure described on the fjr forum web sight which resulted in a very  slight reduction in engine vibration in an already very very smooth running motor.

[dirtrider]

18 minutes ago, JamesW said:

New Yuasa AGM battery installed and TB adjustment completed with good results.  First I went on a 30 mile ride to warm up the bike.  I found that turning the brass screws (air bypass adjustment) out one turn wasn't enough to maintain idle so turned out from seated 2 turns which resulted in a 400 RPM idle and only required minimal adjustment to attain balance going side to side in small increments.  Next I adjusted each throttle plate adjust screw CW going side to side in small increments while maintaining balance on the Harmonizer until idle reached the desired 1150 RPM.  I checked the TPS idle voltage which was 0.375 VDC which supposedly is in spec (0.370 - 0.400).  I'm not sure where this TPS voltage spec came from or if it is correct but all seems well and the bike goes into closed loop as it should when the engine oil temp reaches 5 bars as it always has.  Bike runs great with minimal vibration at speed or at idle.  So for me I'm done with the more cumbersome procedures ( zero-zero or after zero-zero) as discussed in past threads at length.  

 

I actually came up with this method after reading about and performing a very similar procedure described on the fjr forum web sight which resulted in a very  slight reduction in engine vibration in an already very very smooth running motor.

Afternoon James

 

If you go back far enough in the archives you will  probably find this is how we used to do the base idle screw settings before that darn 0=0 nonsense was all over the internet.  (I haven't ever found the 0=0 to work very good as it still takes more adjusting from 0=0  to get it right).

 

The one (important) thing that you need to check yet (especially on the  single cable system) is (with a hot engine) that BOTH side throttle cams start to lift off the base idle screws at the exact same time.   This is more important than having the TB's exactly equal at idle as you don't ride the motorcycle with closed throttles plates.

 

Or, if you can't get them to lift at the exact same time then have the L/H side lead by just a little as the L/H side adds fuel as it opens. If the R/H side lifts first it ONLY adds air with no fuel so you get a little throttle sag at  slow small  throttle openings from curb idle.  

 

 

[JamesW]

Hi D.R.,  I wondered about that and what I did was begin adjustment on the left side because of my single cable system and I only adjusted in very small increments.  I can definetely see how the later boden box system was a huge improvement on the single cable system.  Wish it was easy to retrofit my bike to the boden system.  Didn't notice any throttle sag but I'll be sure and pay close attention, thanks.  I did notice that I didn't have to make any cable adjustment on the right side when checking sync off idle which I didn't expect to find.  Also, before performing this procedure when I would check sync of idle I did notice that right off idle the Harmonizer would move sightly off sync and then return to sync as I rolled the throttle a tiny bit further off idle which may have been an indication of the condition you are referring to.  Interesting!  Thanks for your insight.