EVO All Evo Model Discussion

52 Slow jet

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Old Dec 2, 2018 | 02:42 AM
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Default 52 Slow jet

Have just installed Ev27 cam and SE heads on my 97 Electraglide .
I had the carby apart to rejet and found 185 main and 52 slow jets. The idle air screw has been had at before by a PO. Its fubered. Do you think it's running the 52 slow jet to mask the f'd idle screw?. Because you cant adjust it?
What's your thoughts??
Gas mileage is worse than a mates 96" night train.

Bike only had SE aircleaner when I bought it. So no other mods. Seemed to be majorly over jetted for a stock bike.
I'm going to attempt to drill it out one day this week and install a 45 or so slow jet and adjustable air/idle screw

Bike now has
Ev27, SE Heads,.30 head gasket so 9.5 compression . SE air cleaner. V&H Propipe.

oh am also waiting extended front brake line and wiring extensions to finish off my 12" apes.
 
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Old Dec 2, 2018 | 07:15 AM
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Hard to tell in the pick but if those are flat tops without valve reliefs I would go with a 48.. The best thing to do is install an AFR gauge with a wide band o2 sensor... Then you can get it pretty near perfect throughout the rpm range... I use a Wego III for three years now and no need for a Dyno tune.. Keep it mounted just to keep an eye on my AFR's.. Insurance.....My motor is very built...
 
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Old Dec 2, 2018 | 07:59 AM
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Adding to the Wideband sensor, I'd also get rid of that knackered carb (CV40?) so you have full adjustment of all fuel passages and go down to a 45 pilot.

It's been my experience people throw high pilot jets into bikes with shitty tunes to mask bad tuning.
 
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Old Dec 2, 2018 | 08:57 AM
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52 is for 100 - 110 hp and most likely why the screw is out to lunch, going to be a good chance the needle is rich too because a CV doesn't stay on the low very long in everyday riding to use that much fuel. Sportster type needles work well in a CV, your set up is not on the edge of detonation prone yest but getting close with the early intake valve closing EV27 @ 9.5, it can still build some cylinder heat so be careful since today's gas makes plug reading difficult and lean can be mean to your wallet.
 
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Old Dec 3, 2018 | 12:03 AM
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Originally Posted by 98hotrodfatboy
Hard to tell in the pick but if those are flat tops without valve reliefs I would go with a 48.. The best thing to do is install an AFR gauge with a wide band o2 sensor... ...
Cheers they are stock pistons with valve reliefs.
would like a o2 sensor but that have to wait till next year if I'm lucky
Originally Posted by Mattbastard
Adding to the Wideband sensor, I'd also get rid of that knackered carb (CV40?) so you have full adjustment of all fuel passages and go down to a 45 pilot.

It's been my experience people throw high pilot jets into bikes with shitty tunes to mask bad tuning.
That was my thought. Masking the tune with the 52 jet. I will get another carb when it's in my budget. Not that cheap here in New Zealand.

Originally Posted by 1997bagger
52 is for 100 - 110 hp and most likely why the screw is out to lunch, going to be a good chance the needle is rich too because a CV doesn't stay on the low very long in everyday riding to use that much fuel. Sportster type needles work well in a CV, your set up is not on the edge of detonation prone yest but getting close with the early intake valve closing EV27 @ 9.5, it can still build some cylinder heat so be careful since today's gas makes plug reading difficult and lean can be mean to your wallet.
100+hp would be nice...
I have a replacement needle and 190 jet to start with. Will start rich and work from there.
 
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Old Dec 4, 2018 | 10:48 AM
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Take a look and read the Nightrider website for CV carb tuning information.

http://www.nightrider.com/biketech/hd_cv_mods.htm

http://www.nightrider.com/biketech/hdcvcarbappendix.htm

http://www.nightrider.com/biketech/c...leshooting.htm
 
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Old Dec 5, 2018 | 02:38 AM
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Originally Posted by nallac
Cheers they are stock pistons with valve reliefs.
would like a o2 sensor but that have to wait till next year if I'm lucky

That was my thought. Masking the tune with the 52 jet. I will get another carb when it's in my budget. Not that cheap here in New Zealand.


100+hp would be nice...
I have a replacement needle and 190 jet to start with. Will start rich and work from there.
Hi there, Im in NZ aswell and having tuning issues with my 1995 Dyna. I opened it up and found some large-ish jets, it had dreadful aftermarket slipons so I figured it may have had something better removed previously. Like you I get bad mileage. Would you like to compare notes? David Christchurch
 
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Old Dec 6, 2018 | 01:38 PM
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not tryin to detract here, but stock pistons and a .030 head gasket wont give you 9.5... you would have to mill in the .50 range off the head to start even getting in that range..so tune/jet accordingly.
 
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Old Dec 6, 2018 | 01:51 PM
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Originally Posted by 55 Pan
not tryin to detract here, but stock pistons and a .030 head gasket wont give you 9.5... you would have to mill in the .50 range off the head to start even getting in that range..so tune/jet accordingly.
It's in the SE heads. The combustion chamber is smaller that stock heads... And yes they are a bolt on 9.5:1 with the stock head gasket. A .030" head gasketcould pick it up another .15-.2 possible putting the static comp@ 9.65-9.70:1 .... I believe they are a 76 or 79 cc combustion chamber...
 
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Old Dec 6, 2018 | 09:15 PM
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Originally Posted by 98hotrodfatboy
It's in the SE heads. The combustion chamber is smaller that stock heads... And yes they are a bolt on 9.5:1 with the stock head gasket. A .030" head gasketcould pick it up another .15-.2 possible putting the static comp@ 9.65-9.70:1 .... I believe they are a 76 or 79 cc combustion chamber...

72 cc bathtub chamber, followed the pioneer Branch head design
 
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