Air Screw Adj on 19mm PHBG

Code Name: BLAST! /

okay, I am new to PHBG, so be gentle. I've read the wki and done a search, but I can't totally find what I am looking for.

My set-up:

19 DELL Racing Carb, 90-92 main jet (been testing, 91 in there right now), 7 needle second clip, 60 choke, and not sure what the idle jet is. I have a 42 idle down at Treats that I need to pick up and put in. This is on a K-star case matched, high comp head, race clutch, etc. Pinto.

The bike seemed to run great with the 92, but I would come to a stop sign and the engine would rev way down, like it was gonna die, but it didn't. I screwed the idle in all the way and that didn't help, so I started messing with the air screw and ... that's when things went wrong. And it hasn't been the same since. Basically, it drives awesome when I first start it up and starts right up from being cold, but once it is warmed up, I have problems. The revs go way down at a stop and if I stop revving the motor, it will die. And then it is REALLY hard to get it started again. (no pedal chain, so I have to push, so without a hill it is super impossible to start again).

I am gonna try to go down on the idle jet, but I am wondering if there is a stock setting for the air screw (like turned in all the way and approx how many turns out)??? Just so I can get it back to stock.

The bike is running a bit rich and the plug is getting fouled, which I imagine is why it is hard to start. I am going to try going back down to the 90 (went down to the 91 today, but that didn't help much). And, yeah, I need to get that idle screw changed. It just is not running well enough for me to feel good about driving down to Treats. Thanks for any help and sorry if I am missing easy to spot tuning stuff for the PHBG. I am a total noob. I was fine with the SHA, but this is definitely breaking me in.

Re: Air Screw Adj on 19mm PHBG

Sounds like you need to get your bike warm and start turning the air mixture screw 1/8th turns at a time until you get you low end back. If it's too rich it will gurgle, it's it's too lean it will bog... 90 main sounds kinda high too. Also could just be a shitty plug. You running B7HS?

Re: Air Screw Adj on 19mm PHBG

lean to the right (in=less fuel), rich to the left (out=more fuel)

in this case the fact that it isn't idling makes me think you need to lean it out. If you go all the way in and it's still the same, then go down a size on the idle jet.

also make sure you start with a new plug because you could just be fouling plugs at idle if it's way rich...

Re: Air Screw Adj on 19mm PHBG

Code Name: BLAST! /

yeah, I did a new plug yesterday ... started right up after I put it ... and it's already dirty today.

I am running a B8HS.

I did try the air screw all the way in and my performance was messed up, but I was trying to get home after it died, so I was in less than ideal circumstances for testing.

I'll get the idle jet tomorrow and do more tests.

thanks, Chris. very helpful. I know the wiki has a lot of info, but it seems that I am only able to use it as I, myself, learn. sometimes really simple stuff like "lean to the right (in=less fuel), rich to the left (out=more fuel)" is really, really helpful!! thanks so much

Re: Air Screw Adj on 19mm PHBG

Word. I learned from here too. Just got into the PHBG world 6 months ago maybe?

Do yourself a favor and get some B7's. B8's last about a half hour on my similar setup. 19PHBG, Estoril, 70cc Airsal on an e50... They just foul and suck balls.

I'm running an 87 Main, 40 idle with a b7 needle on the top clip (Leanest setting). I'm also in cincinnati and our humidity makes tuning super fun.

Re: Air Screw Adj on 19mm PHBG

W7

Re: Air Screw Adj on 19mm PHBG

Code Name: BLAST! /

I'll try that ... I tried putting the needle at the top and had trouble starting the bike ... bah!

I think there is definitely a learning curve. Definitely the power increase (over my 16/16 SHA) is worth the effort. And you have to start somewhere ...

Re: Air Screw Adj on 19mm PHBG

I would say don't if your mid range is cool. I did it because I was rich in the middle. Idle jet 0-1/4 throttle, needle position, size, etc 1/4-3/4, Main 3/4-WOT.

Re: Air Screw Adj on 19mm PHBG

The needle shouldn't effect starting. Probably those b8's and too rich of an idle circuit...

Re: Air Screw Adj on 19mm PHBG

sounds like you have too small of an idle jet. my kstar wouldnt idle with a 35 but was perfect with a 42.

Re: Air Screw Adj on 19mm PHBG

Could go either way... It's hard to say without checking it out in person.

Air Screw Adj on 19mm PHBG

#CrazyWayne™ rocks. #CrazyWayne /

Timing is ?

Make it 18 to 19 deg's

Bug's out

Re: Air Screw Adj on 19mm PHBG

Code Name: BLAST! /

oh, forgot, it has the CDI on it ... it's set right in the middle. I put the CDI on separately from the carb, just to be able to trouble shoot, since I am so new at this. And there were no issues whatsoever with the CDI other than blasting the fuck out on it.

I'm gonna drive my car down to get the idle jet. It sucks because my unemployment money is held up and I have zero cash for anything right now. Not even for this $6 jet ... I'm gonna have to put it on a credit card if I can find one with $6 on it ... bah!

Re: Air Screw Adj on 19mm PHBG

It can be frustrating to try to set the idle perfect...if it doesn't idle. Alot of times its hard to know which direction, and how far to go. Also make sure there are no airleaks, this always messes up your idle.

From my expirience, idle mixture is somewhat unpredictible:

e50, 65 metra, boss 21 del: used a 50 idle jet

e50, 65 metra, estoril 21 del: used a 42 idle jet

a35, 70 alukit, estoril 21 del: used 5o idle jet

av10, 50 bidalot, doppler, 19 del: used 45 idle jet

av10, 70 malossi, doppler, 19del: TUNING, but seems to like a 37 best from what I've tried.

I think you know what to do. It's just a matter of trial and error. I'm in the same boat with my current setup on my av10. super hard push start, takes the wind out of me after 2-3 starts, and it doesn't idle so im bumping it all day. Super rough. makes it difficult to make progress if you have to run with it every time you turn your screw a 1/4th turn. It will get way easier to dial it in, just getting that initial idle is a bitch.

Re: Air Screw Adj on 19mm PHBG

1. B7HS.

2. CDI on full advance.

Re: Air Screw Adj on 19mm PHBG

Kyle the Velvet Quaker /

My kstar seems to be a weird one. I'm on a 96 main and I need to go higher.

Right now its a 42 idle, w9 needle( being swapped out for a 7 today) and a 96 main(going higher as well. I'm running a B7 also. Good luck Rob.

Re: Air Screw Adj on 19mm PHBG

Code Name: BLAST! /

The B7 looks perfect. Nice and brown. Not fouled at all.

I put in the 42 idle and went down to an 88 for the main. It ran worse, at first. Four-stroking (bad). Then I put the air screw all the way in and out 1/4 of a turn. It ran much, much better, but it died when I came to a stop at the bottom of a small hill. I only had time to go for a quick run (several blocks, anyway). And this is what I found. It seemed to idle fine on the flats and going up hill (this is at stops after riding up hill or on the flats). It is when I get to the bottom of a hill, after going down the hoill, that it wants to die (I tested this three times ... fine on hills going up, fine on the flats, wants to die at idle at the bottom of a hill). What might that mean?

Re: Air Screw Adj on 19mm PHBG

Code Name: BLAST! /

shit, I forgot the pic.

I haven't fully advanced the timing. I will do that, if I can, tonight.

1245985487_newer_pinto3a.jpg

Re: Air Screw Adj on 19mm PHBG

Code Name: BLAST! /

another pic

1245985560_carb2.jpg

Re: Air Screw Adj on 19mm PHBG

advance your CDI first and see if that takes care of the idling problem. I think it will.

Re: Air Screw Adj on 19mm PHBG

If you run some tubing off those over flow spigots on the sides that hang down past the bowl, it will keep your carb from getting all oily and shit...

Re: Air Screw Adj on 19mm PHBG

yeah, before I even got to the part about the cdi, I was thinking timing. definitely get that going.

Re: Air Screw Adj on 19mm PHBG

Code Name: BLAST! /

ha! I advanced the timing and went down to an 84 main jet (from my old SHA). no difference. I had so many problems with it cutting out last night (barely made it home from a meet up), I figured it was probably the air filter. so, I took off the air filter and put on a different PHBG filter (the big pink butt plug). and .... success. I am gonna keep testing and plug chopping to see where I need to be on the main jet, but for now, problem solved. the parmakit filter was completely wet.

1246055750_pinky.jpg

Re: Air Screw Adj on 19mm PHBG

I was running one of those foam red Malossi trumpet filters and it would get soaked with fuel... I switched to the E12 and upjet one size and it rips...

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