Pages: [1] 2 3

Author Topic: PHBG Tuning Procedure.  (Read 5528 times)

Slink

  • Mid-Mo Peds
  • *
  • Posts: 2314
  • Get Moist!
    • View Profile
PHBG Tuning Procedure.
« on: April 19, 2011, 03:21:00 PM »

I got bored at work and reworked a MA wiki article by MarkRyan on PHBG tuning. I now share my OC twitches:


1.)    Start the bike with the choke on. Let the bike warm up, and then disengage the choke. Adjust the idle-screw until the engine idles well (rear wheel barely moving), then turn it IN a 1/2 turn more. Check for air-leaks. Any leaks would make this whole procedure fruitless.

2.)    The first 1/8 throttle is controlled by the idle-jet, fine tuned by the mixture-screw. Do 1/8 revs. If it is stuttering like it is rich, turn mixture-screw IN. If it is boggy or unresponsive, turn it OUT until it four-strokes, then turn it in until it stops four-stroking. If it is still four-stroking when the mixture-screw is all the way in, lower the idle-jet. If it is still boggy with the mixture-screw all the way out, up-jet. The bike is idle-jetted correctly when it is fast and responsive at 1/8 twists.

3.)   Install a rich estimate for the main-jet. It is far safer to tune from a rich condition than the other way around. Set the needle at the richest setting (clip on the bottom notch). Riding the bike, push all the way to the main-jet at WOT. If the bike does not hit the main-jet due to richness, down-jet or lean the needle (raise clip) and try again. If the bike is four-stroking at WOT, down-jet 1 or 2 jet sizes. Repeat until there is no four-stroking. If it is boggy then up-jet a bunch. Down-jet from the new rich condition as above.

4.)    Between 1/4 and 3/4 throttle listen/feel for four-stroking. If there is four-stroking, lean the needle (raise clip) one notch at a time until there is no four-stroking. If not, leave the needle alone.

5.)    Re-check the response of 1/8 revs and repeat step 2 if necessary.

6.)    With a new plug, do plug-chops. Kill the bike with the kill-switch at each throttle position. Pull the plug and look at the porcelain tip surrounding the electrode to see how lean/rich the bike is at each position. White is very bad (lean). Black is bad (rich). Light-brown to dark-brown is good.

7.)   Up to 1/8 throttle should be responsive. Past 1/8 should be a smooth progression as the needle and main-jet take over. Between 3/4 and WOT, there should only be a slight increase in power. Adjust the idle-screw.

8.)    Set your float level so that when at WOT there is always plenty of fuel. With the carburetor held upside-down, the float arms should be level with the horizontal section of the carburetor body. If the float-bowl ever runs dry, a dangerous lean condition has been created.
« Last Edit: April 20, 2011, 02:45:02 PM by Slink »
Logged
'78 Puch Newport: Stupidly Reliable!
'79 Puch Magnum XK: What? Yeah!
'78 Free Spirit: It's a ripper.

Make it work. Never surrender.

Mike Pee

  • Administrator
  • I.R.E.
  • *
  • Posts: 7539
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #1 on: April 19, 2011, 03:40:04 PM »

Logged

Motorcycle Justin

  • Cold Trailers
  • *
  • Posts: 1537
  • Don't Panic
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #2 on: April 19, 2011, 05:35:30 PM »

THANK you for not being one of the doofuses (doofi?) that thinks the mixture screw affects the whole throttle range
Logged

Slink

  • Mid-Mo Peds
  • *
  • Posts: 2314
  • Get Moist!
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #3 on: April 19, 2011, 05:49:03 PM »

I can learn, just takes a while.
Logged
'78 Puch Newport: Stupidly Reliable!
'79 Puch Magnum XK: What? Yeah!
'78 Free Spirit: It's a ripper.

Make it work. Never surrender.

Motorcycle Justin

  • Cold Trailers
  • *
  • Posts: 1537
  • Don't Panic
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #4 on: April 19, 2011, 11:10:13 PM »

Nah man, you're SMART from the START. I like this writeup.
Logged

Phil N.

  • Mid-Mo Peds
  • *
  • Posts: 4575
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #5 on: April 20, 2011, 07:52:35 AM »

Don't forget to check for airleaks before begining the whole process otherwise your shit will be wrong.
Logged

R.I.P.

  • The Ruffians
  • Posts: 3238
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #6 on: April 20, 2011, 08:31:30 AM »

set the fuel level in the bowl or you be illin.
Logged

Slink

  • Mid-Mo Peds
  • *
  • Posts: 2314
  • Get Moist!
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #7 on: April 20, 2011, 11:29:32 AM »

Included all yalls ideas. Thanks for the critical eyes.
Logged
'78 Puch Newport: Stupidly Reliable!
'79 Puch Magnum XK: What? Yeah!
'78 Free Spirit: It's a ripper.

Make it work. Never surrender.

Motorcycle Justin

  • Cold Trailers
  • *
  • Posts: 1537
  • Don't Panic
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #8 on: April 20, 2011, 02:42:22 PM »

Maybe amend the "set float level" to say "when the carburetor is held upside-down, the float arms should be level with the horizontal section of the carburetor body" (as per the Dell PHBG-specific tuning manual).. "Set" is a little ambiguous
Logged

Slink

  • Mid-Mo Peds
  • *
  • Posts: 2314
  • Get Moist!
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #9 on: April 20, 2011, 02:45:14 PM »

roger
Logged
'78 Puch Newport: Stupidly Reliable!
'79 Puch Magnum XK: What? Yeah!
'78 Free Spirit: It's a ripper.

Make it work. Never surrender.

Phil N.

  • Mid-Mo Peds
  • *
  • Posts: 4575
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #10 on: April 20, 2011, 03:04:51 PM »

Oh yeah and set your timing too, that usually helps a tad.
Logged

Slink

  • Mid-Mo Peds
  • *
  • Posts: 2314
  • Get Moist!
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #11 on: April 20, 2011, 03:12:05 PM »

Oh yeah and set your timing too, that usually helps a tad.

That is another article. Get to writing. I suck at timing.
Logged
'78 Puch Newport: Stupidly Reliable!
'79 Puch Magnum XK: What? Yeah!
'78 Free Spirit: It's a ripper.

Make it work. Never surrender.

R.I.P.

  • The Ruffians
  • Posts: 3238
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #12 on: April 20, 2011, 10:23:22 PM »

Maybe amend the "set float level" to say "when the carburetor is held upside-down, the float arms should be level with the horizontal section of the carburetor body" (as per the Dell PHBG-specific tuning manual).. "Set" is a little ambiguous
i hear ya justin. my carb has a steel band that snaps the bowl on and off, no screws. so when the band is in position with the bowl off and the carb is mounted on the bike, it pretty much shows where the level is set to. kinda like having a clear bowl. it takes 2 seconds to drop the bowl and 15 seconds to rejet and put it back on.
Logged

Lindar

  • Ice Queen/Admin
  • Breakfast Mafia
  • *
  • Posts: 2774
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #13 on: April 23, 2011, 11:49:08 AM »

You should add this to the wiki. Either edit Mark Ryan's page, add this to the bottom of his page, or combine the two PHBG tuning pages into one with this info added. We've been needing to consolidate all that info for a while, and it isn't knowledge I know well enough to feel comfortable deciding which bits get to stay and which need to go.

Also, there already is a timing article. Or rather, there are two - one for points and one for CDI. I could give you the URLs, but it's kind of pointless since the site is down now anyway.

Does anyone wanna comment about the plug chop part? For most of us, it seems to be standard practice to read just the tip of the plug, which is the part that's shown in that one really good "spark plug reading" guide. But it's called a plug CHOP. A few people say that you're supposed to read the base of the plug, and to see down that far, you have to actually cut it. Which is more correct? Or if they're both correct, under which circumstances? I haven't had a whole lot of luck with plug chops and I can't tell rich from lean to save my life. It'd be nice to have a more reliable and efficient tuning method than trial and error.
Logged
1978 Puch Kromag (Swinger): <i>The first-born.</i> Needs work.
1980 Tomos A3: <i>The problem child.</i> Needs tuning.
1978 Sears Free Spirit: <i>The baby.</i> Needs brake work.
1980 Tomos A3: <i>The one that plays with knives.</i> Runs?

Slink

  • Mid-Mo Peds
  • *
  • Posts: 2314
  • Get Moist!
    • View Profile
Re: PHBG Tuning Procedure.
« Reply #14 on: April 26, 2011, 07:19:46 AM »

By all means put it on the MA wiki if you like. I don't care where this ends up but I don't wanna take the time... Go Linda! Go!
Logged
'78 Puch Newport: Stupidly Reliable!
'79 Puch Magnum XK: What? Yeah!
'78 Free Spirit: It's a ripper.

Make it work. Never surrender.
Pages: [1] 2 3