Phbg tuning issues...

Puch 78 free spirit

Treats kit

Dellorto phbg 21

42 idle jet

7w needle

86 main jet

Techno pipe

Here's are my problems:1.  Low end is good when starting but is super weak off the line after I have been riding for a bit. 

2. Mid range seems lean. I was using a 9w then recently went down to 7w. Bottom setting. When ridding in 1/2-3/4 throttle it starts to gasp/die and is fine if I back off throttle. 

3.  As of recently my idle is super high and the mixture screw won't slow it down.

*I recently changed headlamps and do not have it connected yet. Could this break in electrical circuit cause any issues?

*I have read all the tuning info I can find but still need a little guidance. I'm new at this.

Re: Phbg tuning issues...

Generating electricity consumes power by making the genny work like an electric brake. Connect all of your wiring and tune the idle with all the lights on, saves you from stalling at the lights in the rain every single dang time you stop.

Index the throttle beside the grips so you can run her hot at 1/4 1/2 and 3/4 throttle for a good length of road and then do plug chops from each range and tune the needle for the span between idle and WOT.

Re: Phbg tuning issues...

Dane Soderberg /

Awesome. I really appreciate it.

Re: Phbg tuning issues...

Probably Fred /

Your main jet seems lean. Your idle jet seems rich but what atomizer # you running ( 262, 264 ect,). Unless you got a air leak now try about #40-35 idle and then you can up jet the main a size or too. As a rule I never run a carb with much less of a main jet then it comes with new. ( 15 mm bing- 82 main, 19mm phbg comes with a #85 main jet, 21 phbg comes with a 92 main, mikuni 24 flat slide comes with a 135 main to name a few.) ( If they come with different jets they may have 4 stroke atomizers or be clones ) In fact most kits pipes I run take larger main jet then come with the carbs.

I'll port, mod air filters, change slides, change pilot-idle, change pipes ect. But not lean the main. The new carbs come with preset main jets for a reason. A kitted bike with a performance pipe needs to be horrible rich down low sometimes so it won't run lean at wide full throttle on the pipe. Most kits/pipes like to be lean on the bottom and rich on top. Makes you wish for electronic fuel injection on mopeds

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account