Popping between 2000-3000rpm

[rzubonja]

but if i open the boost manually by 1/3 the popping is gone....

it's popping if i cruise in this rpm range and on deceleration.....wot works fine

The setup:
Main DJ 160
PAJ2 DJ 150
Stock springs
Stock needles shimmed 0.80 mm
K&N + some drilled holes on the Y piece
DAM slip on's
Mixture screws are 2.5 out

I tried many different setups...but this seems to be the best....

One more thing...the front headers seems to be an aftermarket product with an increased diameter....back are stock....

From what i have readed here, it seems that i need more fuel (or less air) in this range....

 

[gamorg02]

i would try turning our fuel screws out 1/2 turn each and see if that helps.

 

[SpecOps13]

Yes, that's right at an RPM where the carbs are switching from idle to mid range. 1/2 turn more and if it's better but still not quite right, another half turn. My 89 is 4 turns out right now...

 

[rzubonja]

Yes, that's right at an RPM where the carbs are switching from idle to mid range. 1/2 turn more and if it's better but still not quite right, another half turn. My 89 is 4 turns out right now...

ok, now the popping is gone but the screws are in the 6-7 out range....

one funny thing, i noticed during the 'turning-out' sessions that the screwdriver is going deeper on some screws having the same 'turn-out' number!!!

so i took a measuring device and setted all the screws in the same depth range...after that the turning-out and synching response,and also the overall behaviour improved much in my case.

The side effect is that the mixure is so rich now that i get a headace from the exhaust smell after standing 5. minutes around the bike :biglaugh:

any suggestion on a different setup for less smell :ummm:

 

[sdt354]

You were too lean, now too rich. I'd start with fuel levels and a shotgun cleaning, then a sync. After that I'd reset the idle a/f screws which may have compensated for a different problem at 6 turns out. iMHO
Steve-o

 

[gamorg02]

ok, now the popping is gone but the screws are in the 6-7 out range....

one funny thing, i noticed during the 'turning-out' sessions that the screwdriver is going deeper on some screws having the same 'turn-out' number!!!

so i took a measuring device and setted all the screws in the same depth range...after that the turning-out and synching response,and also the overall behaviour improved much in my case.

The side effect is that the mixure is so rich now that i get a headace from the exhaust smell after standing 5. minutes around the bike :biglaugh:

any suggestion on a different setup for less smell :ummm:

the different height worries me. i'd look in there and make sure they're clean. hopefully sean, danny or another carb expert would chime in.

7 turns is pushing it 6 is borderline ok but if you are there you should probably put your pilot jet up one.

is your exhaust tight?

 

[bazwell]

You were too lean, now too rich. I'd start with fuel levels and a shotgun cleaning, then a sync. After that I'd reset the idle a/f screws which may have compensated for a different problem at 6 turns out. iMHO
Steve-o

The way this thread reads, I'd say this ^ sounds pretty reasonable.
I'd start with the shotgun.

 

[bazwell]

You were too lean, now too rich. I'd start with fuel levels and a shotgun cleaning, then a sync. After that I'd reset the idle a/f screws which may have compensated for a different problem at 6 turns out. iMHO
Steve-o

The way this thread reads, I'd say this ^ sounds pretty reasonable.
If you have done what Steve has suggested already, then shim the needles.

 

[rzubonja]

You were too lean, now too rich. I'd start with fuel levels and a shotgun cleaning, then a sync. After that I'd reset the idle a/f screws which may have compensated for a different problem at 6 turns out. iMHO
Steve-o

i pulled the carbs before...cleaned everything...setted the float levels....synched the carbs....did all the 'normal' stuff before writing here...with limited success

the exhaust is tight...but the rubber on the mainfolds have some cracks, i suppose that that can be the reason for the popping :ummm:

anyway, the complete rubber set is ordered (boost, mainfolds, airbox boots) and i suppose that after the new rubber is mounted the screws can be setted to 'normal' values.

like i said the popping is gone but the max smells now really bad :rofl_200:

 

[bazwell]

Have you looked into shimming the needles?

 

[rzubonja]

Have you looked into shimming the needles?

had stage 1 needles before...tried all clip positions with the 2,5 turn AF setup and still popping

later i took the stock needles and shimmed it by 0.80 mm (0.0314 inches) and started the turn-out sessions which ended at 6. turns out

 

[bazwell]

Yep. I agree with your diagnosis. Maybe it's an air leak, and the new rubbers will fix it. :biglaugh: