Topic: Inconsistent Idle - Over a year later - ALMOST THERE!!! 9/24/11

[trueblue]

Are you certain your cam timing is right, that is the exact symptoms my bike had when the po had the cam timing out a tooth, I was certain it had to be a carb or ignition issue, I pulled the carbs 3 times looking for issues and didn't find any, then when I replaced my noisy cam chain I found the problem

[Gearheadgreg]

Looks like you are getting closer, Reading your thoughts on if the main jet will have effect @ (idle It does not) I have completely removed my main on carb and ran the motor to eliminate the same thoughts that you are experiencing, and there was (no) effect on the idle or slow circuit tuning. The Main does not come into play at all, You may need 1 more step Up on the Idle jet with Pods and Non stock exhaust, I did up to 3 steps richer on the Slow jet and it finally went too rich it was obvious and blacked the sparklers and fouled out just to be sure, at that point i went back 1 step. as we we now the PD carbs Fuel screw will increase mixture will turning (out ) counterclockwise. here is a article and link that may help those who have never removed their main and isolated for tuning diagnoses. > Step 2: DETERMINE THE CORRECT PILOT JET.

    Make sure the bike is warmed up if at all possible.
    Main jet out.
    Needle clip in mid position.
    Turn air screw all the way in then 1/4 turn out.
    Start motor and run it on the stand.
    Adjust idle so the bike will just barely idle.

Condition: Motor running and main jet out.

PILOT JET CORRECT:  With one hand on the throttle maintaining RPM at approximately 1/8 throttle, turn air screw 1/4 turn at a time clock wise until you bottom it out. Motor should become slightly erratic and you should have to play with throttle to maintain RPM. Start turning air screw counter clock wise, 1/4 turn at a time until you have reached 2 3/4 turns out. Between 1 1/4 and 2 1/4 turns, your motor should have reached its highest RPM maintaining a steady throttle. Adjust air screw again between 1 1/4 and 2 1/4 until you have determined highest RPM. Quick throttle response should be clean without bog. Step 2: DETERMINE THE CORRECT PILOT JET. http://scootrs.com/tech.cfm?tip=tunecarb

   

 

 

[bikebitzofvt]

KB~

I can't believe I've missed this tread - thought I'd add my $.02...

I'd check the ignition timing and advancer - if the timings off it could exacerbate the running problem especially after it gets warmed up...  If the advancer's sticking, holding the timing advanced, it could keep her revving high...

Also subscribed, I'll keep following your progress from here...

Good luck!

Tom

[KingCustomCycles.com]

Had inconsistent idle turned out to be valving issues also.  In my case, a leaking intake valve. Have you compression tested to rule out valve leaks?

[cwchan]

Sorry if this has been brought up already...but did you consider the the ignition side of things? Did you time the ignition?  Are they stock coils? Maybe the spark plug wires are corroded and need replacement.  The plugs caps could also need replacement

http://forums.sohc4.net/index.php?topic=67096.0

[Danno]

if you bumped up the main jets 10 you need to bump up the slow jets 2 so 40 to 42

[KB02]

Thanks for the responses.

- The Cam is the WebCam 36a cut. I have timed it in to the best of my ability with numbers confirmed by members of this board to be good numbers.

- The Ignition is the optical ignition from Cycle-X. I have set the timing according to the directions three or four times now. I am running a VOES switch on that ignition as per KingCustom's suggestion and directions (The problem persisted PRIOR to the installation of that switch and I have tested it without the switch hooked up as well just to eliminate it).

- I have not yet checked compression. The last time I had used my compression tester it had appeared to have sh!t the bed, so I may need to get a new one. I hadn't thought that it could be a compression issue.

The forecast shows rain from now until doomsday so it may be a bit before I am able to do more testing...

[KB02]

if you bumped up the main jets 10 you need to bump up the slow jets 2 so 40 to 42

DING! DING!! DING!!!
   - I think we may have a winner!!

Okay, with the #38 idle jet in place I was able to get the hanging idle issue to go away but only by turning down the idle adjust screw to a point that it would not idle. It would just stall out. I tried the mixture needles at 1 1/2 turns out and then again at 2 1/2 turns out and nothing. With the NSRA show in town, I really wanted to ride my little hot rod so I figured I would make one more try and turned them out 4 full turns from seated (about max the screw's effectiveness. THE BIKE WOULD ALMOST IDLE!!!!! At this point I am psyched with "Almost" after what I have been going through. The bike would hold a VERY slow and would stall out after a short time BUT it meant that I was on the right path. The transition from idle to moving was much better as well (previously I would have to ride the clutch like crazy to get it going). I think one more step up in the idle jets (so two steps above stock) will put this bike where it will run happily.


SO CLOSE, AND YET SO FAR AWAY...

As of Friday next week, I will be out of a job.    All fund that do not need to be spent on extranious things will not be spent. Hence, new jets will need to wait (unless anyone happens to have a set of 4 #40 press-in jets they would be willing to give me or trade me for a set of #38's or #35's). Plus with fall and winter coming up quickly I may just tuck the bike in the back of the garage and let it sit until spring - not what I want to do, but tinkering will have to wait if it requires buying anything else for the bike at the curent point in time.

Anyway, I am zeroing in on the solution with the help of the people on this board, so thank you. It has been tough even finding time just to tinker and test ride this sucker. Hopefully I can get a better job with less time requirment that is a lot closer to home. That will make a LOT of things better.

[bikebitzofvt]

Glad to hear you're getting closer - as you have extra jets it might be time to start drilling 'em - a set of jeweller's drills work really well for this.

Sux to hear about your job.  State of VT has a lot of vacant positions listed up your way - maybe worth looking into?

Take care!

Tom