On Fri, 17 Oct 1997 02:33:34 -0500 ncarter "at" worldchat.com (ncarter) writes:
>Hi Chris
>
>RE FANTIC 249-96 Section
>
>Perhaps you can shed some light on a carb problem we have up here in
>cooler Canada. Forgetting the loosely translated manual thats usually a year behind
>we recd a PHBH26BD Dellorto, with following jets:-
>Main 120
>Min 50
>Starting 60
>Spray nozzle AE266
>
>The bike runs very rich on idle, and not at all smooth, with no effect
>from altering the air/fuel screw. A change to a Min 35 was too lean, and a
>44 seems better but not fully tested yet.
>Carb seems fine other than at idle.
>
>Mixture 70:1, as 50:1 'wet stacks' the exhaust, but right now the
>plugs are fouling several times during a ride hence the min jet changes.
>
>Flywheel weight added, and timing retarded, makes it much smoother but
>is masking real carb problem.
>
>Can you please offer any suggestions, as had previously believed that
>the 96's were better carburetted than the 95's.
>
>Kind rgds
>NC 8^)
>
ncarter:

Yes, the `96 is indeed much better carbureted than the `95. Mine is just fine after minor tweaking. Checking my records, I have the following in my Dell'Orto.

Bike: Fantic Section 249 `96 first half of production year.
Carb Type: Dell'Orto PHBL 26 BD
Main: 120
Pilot: 50
Needle Jet ('spray nozzle'): AE266
Jet Needle: D37 (raised one notch to eliminate ping on heavy throttle applications under load)
Slide: 50 degrees
Starter Jet: From 60 to 80 for better cold weather starting (or drill out with .031" drill)
Float level: End of tang is .748" from flat of carb body (lowered level to make it slightly more lean)
Vent Hoses: 2 separate hoses 10" long
Fuel: 1/2 Super unleaded and 1/2 110 octane racing fuel.
Premix: Klotz Techniplate synthetic at no less than 100:1
Reeds: Boyessen two-stage
Air Filter: Twin Air (I think) larger after market filter oiled with filter oil and squeezed out (stock filter sucks)
Power Valve: Wired full open all the time and removed the governor mechanism from the primary case (less 350g and quieter). This did not change jetting, as the power valve has only a minor effect on how the motor runs (80% marketing BS)

I have been surprised at the performance of this Dell'Orto. I usually chuck them in the waste bin in lieu of Mikuni.

Check your reeds carefully. Sometimes poor sealing can affect low throttle performance. DO NOT MIX OIL RICHER THAN 100:1. More oil does no good at all and can screw up low throttle response. I have had several people recently tell me that richer oil mixture have caused low speed blubbering. You may have an oil soaked muffler as well which will slightly affect exhaust volume and make the bike louder. Make sure too that your muffler is not leaking at the header junction and the final muffle junction. Mine melted at the final muffler junction, requiring some silicone RTV. How about that float level.

Hope this helps.

Chris Johnson
Director of Engineering,
College Park Industries, Inc.
(810) 294-7950 (at CPI), (616) 664-4173 (home office)
papazit "at" juno.com