pilot jet question

went for a 50 mile blast today and i have a problem that still wont go away....at about 3k i have an intermttent farting out of the pods.it seems to be worse during the first 20 mins of riding and does it rarely when warm...it was worse
just after rejetting and got a little better richening the pilot srews on the bottom front of bowls.
i m guessing 3k is just about the point before the mains help out...never farts above 4500 and pulls great to redline....plugs look good and valves just adjusted....no change.....i have #20 pilots clipped at the 4th position....in a 50 mile ride it did it probably 8-9 times....i m thinking up one more size on pilots and would i need to change clip position? details: v and h pipe, k and n s and dyna ignition, vm26ss,...bike runs great otherwise...
thoughts?....thanks in advance.....keith

If not already done, would double-check ignition timing with strobe-type timing light, and assure that the advancer unit is properly functioning (not sticking) by watching it move back and forth as rpm are varied. Thinking it's possibly sticking more-so when cold and then loosening up some when the engine warms.

Would also install a brand-new set of NGKB8ES spark plugs and test ride to see whether problem persists. Regardless of how good the existing plugs may appear on visual inspection.

Would also assure that battery is good and fully charged with correct fluid levels. And assure clean tight cable connections at terminals, and good solid ground connection where negative cable attaches to engine or ground.

Are the old original ignition coils and plug wires and plug caps still being used? Thinking ignition (spark) may be weak for whatever reason and causing less problem when engine is warm.

Good Luck!

all good points and hints.....thanks

Patton wrote:

If not already done, would double-check ignition timing with strobe-type timing light, and assure that the advancer unit is properly functioning (not sticking) by watching it move back and forth as rpm are varied. Thinking it's possibly sticking more-so when cold and then loosening up some when the engine warms.

Would also install a brand-new set of NGKB8ES spark plugs and test ride to see whether problem persists. Regardless of how good the existing plugs may appear on visual inspection.

Would also assure that battery is good and fully charged with correct fluid levels. And assure clean tight cable connections at terminals, and good solid ground connection where negative cable attaches to engine or ground.



Are the old original ignition coils and plug wires and plug caps still being used? Thinking ignition (spark) may be weak for whatever reason and causing less problem when engine is warm.

Good Luck!

to get to advancer just pull the two srews holding down electronic ignition module under the points cover? this bike has been neglected on a lot of the little stuff....i m sure the advancer needs lube and i can rule it out.....done a lot of riding, but this is the first ride i am actually getting my hands dirty on.....thanks

Am thinking Dyna-S has three screws through slotted holes attaching its round back plate to the engine.

[Click on image to enlarge view]



After removing the Dyna-S, the advancer is held by a bolt into end of the crankshaft (14mm??).

Recall the 17mm "fake" nut used for hand-turning the crankshaft, which avoids stripping threads of the smaller bolt and threads inside crankshaft.

Hold the 17mm "fake" nut to keep the crankshaft from turning while unscrewing and removing the smaller bolt.

The advancer unit and Dyna-S rotor should pull away. Inspect, clean and lube the advancer unit.

Notice the small magnet imbedded into the Dyna-S rotor.

When re-assembling, assure the magnet is in the 9 o'clock position when the F mark for 1/4 aligns with the fixed timing mark on the engine case. This avoids a 180 degree mistake in orientation of the rotor by assuring the magnet passes the left-hand Dyna-S module to signal the coil which fires the two outside spark plugs #1 and #4.

Re-attach the Dyna-S, and re-set the timing. Approximate center of the elongated holes may already produce nearly correct timing.

Good Luck!

thanks...

keith1 wrote:

thanks...

whats the lube of choice for the advancer..?

Am thinking the FSM just says to oil it and put grease in the grove, without specifying much more.

I have success using molybendium grease, but realize there may be better alternatives.

Patton wrote:

Am thinking the FSM just says to oil it and put grease in the grove, without specifying much more.

I have success using molybendium grease, but realize there may be better alternatives.

After I saw how the greases scummed up on it, I stripped it bone clean with solvent and just oiled the pivots.