Flash III PhaseII: Tuning MadDog's Worst (Again!) Setup

[Wheelman-111]

Greetings:

A happy side-effect of the Pirelli SL26 in the 90/90 size up front is that it almost perfectly compensates for Honda-sans hopelessly optimistic speedometer. Yup, 35 indicated was 34.5 on the GPS. Under 1.5% error, still on the safe optimistic side.

Tonight I installed the Polini 248-006 belt for Italjet and Derbi Vamos. 668x16.25. I incorrectly shimmed the front pulley boss 1.25mm and immediately hit a snag. When I started it the noise was immediately apparent: The kickstarter castles were just barely caressing each other. A temporary fix with a couple of washers between case and cover let me go out and test. I'll get and glue on a second gasket. Edit: The shim should go between the ramp plate and the boss, not behind the ramp plate.

Oddly, despite riding the very outer rim of the driven pulley, take-offs are not much different. Engine speed through the midrange also about the same. Seems to drop RPM a bit sooner as I approach top speed and may need lighter rollers to get over the top. However peak speed of 53.0 on the GPS was without trying very hard - better than the first-run 52.6 in Build Chronicles. Still running 340 at WOT, up to 375 when I let off.

[808BMW]

I know a lot of people that have washers on the case to clear the ZX drive boss (which everyone here seems to have, even without the rest of the pieces). The local shop sells a super thick rubber washer, I think it may be for the SYM dd50? Either way it is much thicker than the paper gasket (or 5 of them ) that I order from Honda.

I run a full ZX trans, including the kicker case. It has the extra space needed to clear the drive face.

[Rob]

so how much taller is the new tire u installed does it handle better on the road what was the reason u went with this tire

[Rob]

what i was trying to ask is how much taller the tire is from stock ?

and the reason for going to the new tire u have now on your elite.

sorry for the jumbo all in one sentence earlier

[Wheelman-111]

Greetings:

Sl26 reasons:

0.36" taller.

Better traction/braking/cornering from considerably wider, flatter profile.

Racy tread pattern.

I had one, waited for taller stand.

[Rob]

so u running the same tire on the back of your scooter all so

[Wheelman-111]

Greetings:

Yes, Pirelli SL26es Fore and Aft. Ready for Track Day.

[Wheelman-111]

Greetings:

I started nibbling at optimizing the tranny as break-in reaches completion. 7-gram rollers made way for 6.8, now intending to install 6.5s the next time I dismantle. RPMs went from 65-ish to around 7K or so for brisk cruising. Maybe 7200 at WOT, but the engine definitely makes more power up a bit higher, suggested by top speed runs where it unwinds to 8-ish.

I had been playing with a 1.5cm longer Polini Kevlar belt that's also 16.25mm wide. (earlier statements were incorrect. In order to retain brisk take-offs, a shim of at least .75mm was necessary.

My only washer candidate put the drive face outer pulley into contact with the kickstarter castle, so I shimmed out the cover awaiting a stack of cover gaskets I plan to glue on. Now I've located thinner boss shims which should work better.

Sutherland's Hardware Store had an extensive washer collection: As thin as 0.8mm spring-steel jobs (that also act as a lockwasher...) to 2mm. All with an ID of 12mm, and a narrow band that shouldn't protrude beyond the boss diameter.
Note that I started off by putting the shim behindthe ramp plate. Further reflection led me to surmise that this is not optimal as it moves the entire variator assembly out of alignment. Better to shim inside the ramp plate, so that the boss is effectively longer (to increase space for the wider belt...) without the misalignment issue. Experimentation begins tonight.

[bradthreee]

When you figure out which belt works best with FlashIII, sell one to me as FlashII is in dire need

[Wheelman-111]

Greetings:

Shimmed 1.2mm between the boss and ramp plate to accommodate the 16.25 Polini 248.006, which is ~1.5cm. longer than stock. This allowed enough room between the front sheaves to let the belt ride all the way down to center. The increased length brought it to a little above the rim out back.


Instant ZX trans! Also swapped to 6.5g rollers from 7s. Cruise RPM rose from 6500 to 7200 with 7900 and climbing at WOT. Once again there is the threat of wheelies as I also adjusted the Polini clutch up to engage at ~4K. There isn't enough clutch grab to take full advantage of the Nik's power at launch.

Top speed remains to be determined, but it put the speedo needle flat in 1/8 mile for an easy 55. Temps oddly enough fell off a little to 300-325 during this abuse.

The stock carb and intake may be the choke point now.

[808BMW]

How many miles are on your bore? Temps will lower/even out and you get more power once the motor is broken in. That's probably why your bike was a bit disappointing at first (compared to flash II) and it keeps getting faster on every ride.

[Wheelman-111]

Greetings:

Approaching ~200 miles, or perhaps 3 tankfuls now. Power seems to be getting better. Hard to tell without GPS and recent front tire swap - the speedo now reads less optimistically, and very near true but the scale hard to decipher.

21-24mm carb was my thinking as well. I can go manual choke for sure, but I'd like to keep the pump + 50/1 premix. The Mikuni would do that for sure. I'll explore my options with the CT mani. I emailed Benji at Treatland to ax him about spigot spacers and cables. I've always been fond of Mikunis, and this one has an oil port right at the venturi.

[Wheelman-111]

Greetings:

This high-riding Polini Kevlar 248.006 belt with a 1.2mm boss shim:


restored take-off to quicker-than-stock levels despite 9:1 gears. The bad news is a top speed of 52.4 at a high-ish 9600 RPM. The good news is that the engine reaches that speed with a stock carb and intake. WOW!

I think the belt is too long/maybe wide? to dig all the way down the driven face. It would appear that I need a little more variator diameter with this pulley setup. I forgot to magic-mark the pulley faces to assess the belt's full excursion, but that's what I believe is happening. Stock belt went over 58 with less revs.

Anybody got a decent Ruck vario? Complete ZX Trans? Chrome vented clutch bell?? That overnight rust is bugging me! Stop me before I paint again...

Much as I hate to admit that MadDog could be right, maybe I just need to swap the 9:1 for 8.4s. Mikuni TM24 ordered, installation to come.

[Bear45-70]

Wheelieboy, You do know that in the high performance world of carburetion that,

"A lot of little holes are better than one big one."

[Wheelman-111]

Greetings:

The Bear axt:

Wheelieboy, You do know that in the high performance world of carburetion that,

"A lot of little holes are better than one big one."?

Yes, in fact that was my Dating Motto during much of my young adulthood. Not sure how it applies to the Variator issue at hand, but perhaps you mean the Mikuni?