Pilot Screw settings

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I wonder about pilot screw settings

I see multiple times on Katriders that Pilot Screws under the standard should be 2.5 turns out. However Original settings / Katana Wiki tells me the carbs settings: carbs [2,3] - 2.25 turns out; while carbs [1,4] 3.25 turns out!! SEE THE APPENDIX

Today I took my Stock Suzuki GSX750F from 2004 for Spring Time Fine tuning and found that if I make all pilot screws 2.5 turns out - they would be unequal!! I was confused and made it all equal (measured on eye with a help of powerful lamp).
So I got it now the following - carbs [2 and 3] - 2.5 turns out and carbs [1 and 4] - 2,75 turns out. In this case all pilot screws are equally closing its holes. Now the engine runs better.

Can someone explain to me why cars 2and3 are different from cars 1and4. And what are the best settings? Thank you.

[Purplehaze]

More out = more fuel.

Post carbs have one line coming in to feed all the bowls, so naturally the outer bowls will receive a tad less fuel. Opening more turns compensates for this.

'2.5 turns out' should never be stated as what-it-absolutely-must-be-set-at. It is always suggested as a starting point for fine tuning.

The best settings are whatever allows you bike to run best, and whatever allows the carbs to be balanced. For my *pre* that means that it starts up in 75degF+ weather with no choke, and isn't running lean or rich after my fine tuning.

My suggested route is:
Set at 2.5
Carb Sync
Idle drop (finds best mixture)
Carb Sync

[arsenic]

'2.5 turns out' should never be stated as what-it-absolutely-must-be-set-at. It is always suggested as a starting point for fine tuning.

He's right, if your carbs aren't clean, which let's face, on KR they aren't. The settings are all over the place. However, if your carbs aren't fucked up, it's 2.5 turns out.

[maniac1886]

I have all 4 of my carbs on my pre set to 2.5 turns out. Then balance them with a manometer and the individual adjustment screws between the carb bodies. That should effectively balance your carbs with the FA screws all at the same amount of turns. Again, that's considering you have clean carbs. In my opinion, the only way you are going to efficiently be able to tune those FA screws (with clean, balanced carbs) is with a dyno. I dont know if that's the case for people like arsenic, but for the average dude I feel like thats the case.

I've never seen Post carbs in person so I could be completely wrong. I'm not too keen on the differences.

[TRPUT]

The OP has a Euro spec bike. About the only setting the same as a stock US bike is float height. Depending on where it originated in Europe, it may have different idle jets, main jets, needle jets and jet needles ... and ignition timing. Those differences require different tune settings which may include variances in AF settings between 1/4 and 2/3. It seems to me the OP has proven for himself why the manual lists those AF screw variances for Euro bikes.

Oz bikes are Euro spec. My AF screws are set at #1 & 4 - 2&1/8 turns and #2 & 3 - 2 turns. And that's set using an AF meter and IR thermometer.

[maniac1886]

Oh crap. Good call on location. I always forget to look. Yah... I don't know shit about European spec. Lol

[arsenic]

Oh crap. Good call on location. I always forget to look. Yah... I don't know shit about European spec. Lol

Me neither

[Kreylyn]

The OP has a Euro spec bike. About the only setting the same as a stock US bike is float height. Depending on where it originated in Europe, it may have different idle jets, main jets, needle jets and jet needles ... and ignition timing. Those differences require different tune settings which may include variances in AF settings between 1/4 and 2/3. It seems to me the OP has proven for himself why the manual lists those AF screw variances for Euro bikes.

Oz bikes are Euro spec. My AF screws are set at #1 & 4 - 2&1/8 turns and #2 & 3 - 2 turns. And that's set using an AF meter and IR thermometer.

+1


The manta for 2.5 turns is ONLY a starting point, and to be honest... the majority of the time this site is US centric so over looking location is easy to do sometimes.


2.5 turns -It will make your bike run.


It SHOULD be tuned from that point. For US bikes, it's close enough to run the bike though.


Euro specs may have slight variances and even a better starting point than 2.5 turns out as has been strongly suggested (specs and experience as posted above).


Doesn't mean that all bikes shouldn't be fine tuned for the best performance. If your skipping that step, well... your NOT doing the job right. Your just getting by.


Krey