KZ650 - STILL not possible for WOT :-(

zed1015 wrote:

Colder is B9ES.
Backfiring on decel can be caused by excess fuel being burnt in the exhaust but can also be caused by other issues such as an exhaust air leak etc.
If backing off the throttle at WOT improves running you may need smaller main jet.

Another thought.. Have you tried running the bike with the pods removed..

Interesting, right now tested B9ES. MUCH better performance, able to squeeze her out in 3rd close to 9.500 with no jerking at WOT. 4rd little jerking, but able to reach 8.5k. Massive boost was detectable closing throttle to half. 5th on WOT she is still not there, but jerking massive less then with B8 or B7 plugs. How could this happen?
 See below plug from 4 after hard ridden 60km.
 Looks better!
 Detonation sound is reduced around 5 to 7k.
Should I remove the one shim on needle or test 105 mains?
 

The needle mainly controls off idle to upper mid range and the mains begin to dominate the upper mid on to WOT.
Moving the needle won't affect wot so drop a size on the main to lean off the top end.
The colder plug sheds heat faster and runs cooler so will reduce detonation.
Is this plug pic after a high speed chop or just taken out after normal ride and slow down to a stop.
If not a chop then the plug only indicates running conditons at idle.
For signs of detonation inspect the porcelain for tiny black specks or aluminium.
Good jetting should show full ring of colour / light soot on the base ring .
Correct plug heat range will show as a colour change halfway on the ground electrode close to the bend..

 

zed1015 wrote:

The needle mainly controls off idle to upper mid range and the mains begin to dominate the upper mid on to WOT.
Moving the needle won't affect wot so drop a size on the main to lean off the top end.
The colder plug sheds heat faster and runs cooler so will reduce detonation.
Is this plug pic after a high speed chop or just taken out after normal ride and slow down to a stop.
If not a chop then the plug only indicates running conditons at idle.
For signs of detonation inspect the porcelain for tiny black specks or aluminium.
Good jetting should show full ring of colour / light soot on the base ring .
Correct plug heat range will show as a colour change halfway on the ground electrode close to the bend..


 

Last picture was no wot plug chop. Only checked after some hard kilometres.

 Have again checked wot and using choke. Jerking becomes little more and due massive boost after reducing throttle at 4th redline I am quite sure to need 105 or 102.5. Think will test 102 to see what will happen.
 Think I am on a good way. During this week Dyna ignition will arrive to sort out ignition problems.
O-8 Needle jet is correct? Can this part influence WOT section negative?

The choke now affecting WOT fueling is a good sign.
Only drop one size at a time on the mains so try the 105 .
You also mentioned shims on the needle which i somehow missed on your other reply..
These shouldn't be needed with the air correctors so i would remove those first and test before dropping the main to 105 .
Did you try a run without the pods fitted ?
They are genuine K&N aren't they and not masking any of the air passages ?

Depending on model the needle jet varies from a 0.8 to 0.4
Here's a chart to help identify which carbs you have in case the donor carbs were a different spec but every set that uses the 5DL3 needle matches with the 0.8 jet as you have so that is correct and i would rule that out ..
 

After reading all of this I have to say One Thing At A Time then move on. 

F64 wrote:

Yeah, Wookie it's a weird one. I tried to find the installation instructions last night. It has a positive coil wire tie in.
I'll dig up the instructions and post when I get back home.


photo: W&W Cycles
 

zed1015 wrote:

The choke now affecting WOT fueling is a good sign.
Only drop one size at a time on the mains so try the 105 .
You also mentioned shims on the needle which i somehow missed on your other reply..
These shouldn't be needed with the air correctors so i would remove those first and test before dropping the main to 105 .
Did you try a run without the pods fitted ?
They are genuine K&N aren't they and not masking any of the air passages ?

Depending on model the needle jet varies from a 0.8 to 0.4
Here's a chart to help identify which carbs you have in case the donor carbs were a different spec but every set that uses the 5DL3 needle matches with the 0.8 jet as you have so that is correct and i would rule that out ..
 

Tested today 105 mains. Jerking still exists, but little better. Top Speed plus 9kmh to last run with 107.5 mains.
 Use genuine K&N pods which as far as I can see mask nothing. Will perform test run without pods next time.

 Next I will test Dyna ignition.
 Then removing if needed this shim. But I need that shim to avoid hole arround 2k.
 
 

Can you confirm your carb settings.
15 pilot.
5DL3 needle on 4th groove from top and shim or is it 5th groove and shim.
0.8 needle jet.
1.5 slide cutaway.
105 mains.
Your engine is basically stock with just a slight capacity increase and should have only needed the air jets and main jet change.
The needle should not have needed lifting and you are now only one size up from stock on the mains and nearly back to stock settings which is what should have worked at the start..
I would stop there with the 105 and look at the needle height first to address the "hole" and see how close you can get back to the 4th groove before or if it re-appears.
I think 5th groove and shim is too far and would first try the 4th groove alone, then 4th groove with shim and then 5th groove alone and stop at which ever clears the "hole" if it is still there.
The overall fueling is a stack up of all the circuits so getting that needle down will fractionally lean off the WOT.
Maybe your off idle hole was actually bogging caused by the over rich 17.5 pilot which has now been changed ?







 

zed1015 wrote:

Can you confirm your carb settings.
15 pilot.
5DL3 needle on 4th groove from top ( and shim )
0.8 needle jet.
1.5 slide cutaway.
105 mains.






 

Yes, exactly current configuration plus installed correctors and K&N pods.

 Edit: Unknown quality (mean tolerances) Keyster Y63 needle which should be same as 5DL3…
 

Womtong wrote:

zed1015 wrote:

Can you confirm your carb settings.
15 pilot.
5DL3 needle on 4th groove from top ( and shim )
0.8 needle jet.
1.5 slide cutaway.
105 mains.







 

Yes, exactly current configuration plus installed correctors and K&N pods.

 Edit: Unknown quality (mean tolerances) Keyster Y63 needle which should be same as 5DL3…

 

So the needle is now back to stock 4th groove and shim from 5th groove and shim as well as stock pilot and "hole" is not present.
Apart from the shim the carbs are now pretty much how they should have been set from the start.
With the main only one size up from stock i would now try it without the shim before going any further.
At the beginning you had a larger pilot and raised needle which should not have been used with the air correctors.
This results in massive overfueling off idle and midrange which causes bogging and could be mistaken for a lean condition the same as the mains were.
Hopefully the shim won't be needed unless the Keyster needle is not the exact 5DL3 dimensions but i'd be surprised if that was the case as all the Keyster i have used has been exact.

 

Ok, will work as suggested from you.
Thanks a lot, seems to be on a good way!
 

Have found what was the problem: That fu***** ignition was again faulty!
 Just installed Dyna S and problems are away!
😀
 Completely different bike now: VERY sharp from 5 to 8k, and jerking is away.
 New for me is the behaviour at startup with choke: She runs now at about 3.5k (before 2.3k) and after 3 to 4km warmup she runs nice.
 Only must remove the shim from needle and I think I am finally at the end with 105 mains, 15 pilot and richest clip position on needle like Zed has mentioned from beginning.

 Crazy, so much testing and jetting only because of that ignition.

 Maybe I will switch from black coils (Dyna 5Ohm) to the green 3Ohm because I have them in the rack. 

Interesting, Dyna ignition occur to interferences to my Daytona speedo. RPM indication is little jumping at 5k.

 However, thanks to everybody for the ideas and help!

 Greetings to everybody!