Flash 3.26

[Wheelman-111]

Greetings:

Thanks, Jon!

I dismantled the belt drive in the 36-degree Deepinnharta evening.
The Polini 248.035 belt has worn down from 18.2 to 17.95mm with the typical 0.02 variation around its circumference.
I have a Polini 2-shoe adjustable and didn't bother to check its balance. My weights are all yellow Polini 5.3s for 33 g total and without significant wear.
I did find my aging blue Polini vario guides had worn to a pretty loose fit in my Giant 97mm BrandX variator.
Enough so that I could wobble the ramp plate inside the variator with my fingers.
In went a trio of new ones, and I reduced my boss shim thickness by 0.4mm so the belt now stays tight between the pulleys.
Hopefully this fixes the issue. I'll test manana - low of 27 F is forecast but clear and dry.
I'll be packin' the GPS.

BTW if you really want to sell that SR, have the lovely Ms. Angie pose in some "provocative" pics on the scooter and include a couple of 8x10 glossies with the scooter purchase.
Might even buy it myself...

[Wheelman-111]

Greetings:

Finally got around to installing the OKO 26. Jetting is always a guessing game, and I guessed pretty close with. 52/125 and K44 needle.
Very linear on throttle take-up with air bleed at 1-5/8ths out. Temps about the same as with the OKO 24 which was running 50/118. No spikes off-throttle, and good power at WOT with 300 or so on CHT.

With Ghost running a 21 successfully and my own hardship trying out a 30, I had wondered whether a 26 might be tough to tune. Not so.

Bakaracer had suggested the 26 might open up greater speed potential than the 24. That remains to be determined, but at least it's rideable around town.

Flash 3.2 demonstrated 66.3 MPH with the 24. I'll post resultd when I can.
Anybody need a 24 with Power Jet? Never did get around to enabling that feature.

[customx22]

Just slap on a 28mm I hit 70+mph with it 68mph avg.if you have the money buy a arrow pipe like sanjoro.for sure you'll go way more fast.

[Wheelman-111]

Greetings:

Home from work on Deepinnaharta Freeway tonight, the 26 didn't make it any slower; 65.9 MPH, hauling my briefcase on my back and full mirror regalia. And Wheelman don't tuck. No wind to speak of and no hill either. All Corsa.

Since it went 66.3 with the 24mm OKO, and the 26 has only my "initial Hunch" jets, there's a very good chance I can get it faster. Temp after about 45 seconds at WOT crept up to near 350, perhaps a bit warmer but not much more than the 24 was giving.

Currently 52/125 with K44 needle.

[StrokedSr]

ay wheel man...you know which carb i want to try out next..since i have the ct mani...is the areeche 21mm..they are sold down here in Key West

[Wheelman-111]

Greetings:

I really liked an Arreche 17.5 I had on an early Areo build. Good quality carb. Does it come with the CT-size spigot.
Ghost says the 21 OKO is big enough, should be the same for Arreche.

Friday I couldn't get Flash to idle suddenly. I'll have to hunt it down. Reeds going or vac leak?

[StrokedSr]

i dont think its that big actually.. so who knows just gotta try it n see..check the reeds but it was suddenly you said..were you running parked it and then came to discover this prob?

[Wheelman-111]

Greetings:

Be sure to Pic and Post your Arreche Axperience, Dawg!

Yup, I apologize for keeping several thousand Fervid Forumistas from a good night's sleep.
It seems the issue was, for a change, a simple one: my CT clamp was stripped. I began by seeing if I could reproduce the symptom by wobbling the carb as the engine warmed on the "choke".
It didn't stumble, but the carb seemed oddly loose in the donut.
I went to tighten the worm-drive hose clamp and - "Thunk!" - with a loss of screw resistance.
My theory about why it ran at every other engine speed?

The carb has a fairly snug fit in the rubber sleeve. The sleeve has a ridge that engages a groove in the carb spigot.
Evidently when the engine revs are high enough, the rubber contracts by vacuum around the carb pipe spigot and all is well. Sort of like a snorkeling mask sucks down onto your face when you inhale through your nose, right?.
However, when the revs drop, the rubber relaxes and a little air gets in, leaning the mixture and leading to a stall.

New clamp installed with judicious application of Legendary Wheelman Strength, and all is well at idle and all other speeds.

(MadDog's boss once recruited me to Air Force One; I was asked to serve as Diamond Perfector.
No machine could apply enough pressure to rid the First Lady's jewellery of inclusions and imperfections without unsightly scratches on the diamond...)

It's scary to think about what could've happened; the other low-vacuum situation occurs at WOT! I went 65 with it for a half-mile, backing off when I noticed the temps atypically over 350!!
Anyway, go easy on the torque you apply to these Chinese-made clamps and it should be OK.

[Wheelman-111]

Greetings:

The fixed CT clamp seems to have fixed my weird cold start issues too.
Temps have calmed down, and plug darkening up nicely.
Never try to tune jetting with an air leak.

[Wheelman-111]

Greetings:

A New World Record od 66.4 recorded on the way home from work.

F3.26MPH66.4.jpg (57.72 KiB) Viewed 6140 times

Hauling my Courier's bag, mirrors on, and Wheelman don't tuck.

No hills in Deepinnaharta, and believe or not, against a light (2-5MPH) North wind.

Despite that, still whopping whole 0.1 MPH faster than with the 24mm! Woo-hoo!!

[bakaracer]

Do you have a tach hooked up?what rpm is it hitting at that speed?

[Wheelman-111]

Greetings:

Yes but it's the cheap version of TinyTach, which is limited to 9999. The most I've ever seen is 0400, which I take to be 10,400 RPM. Judging by the tune the engine is singing, it's probably about right. At peak speeds, eyes well up with Wheel-tears and it's not a good idea to be looking down so far for too long.

The OKO 26 might have opened up a few hundred RPM more at the top than the 24 could support, but you're right; if I want to go faster I'll probably need a more exotic pipe than the PG long and maybe do some more case porting and bigger intake. I expect this to be a 70 MPH build in ideal conditions and a long run-up, maybe a bit more once I install the 7.58:1s.

[Wheelman-111]

Greetings:

There are 20 TinyTach-confirmed hours and about 400 miles added to the used Corsa bore. Bad weather is forecast for a couple of days, so maybe a good time to bring the block into the Boudoir for a look-see.
It has run very well every day I've axt it, up to 66.4 MPH and that wasn't a real long run. Just mingling with Deepinnaharta Freeway traffic, really.

Still, I was perturbed by a messy exhaust flange leak, and discovered a minor base gasket leak as well. Hopefully my assembly errors and experience will benefit other Corsa enthusiasts and myself down the road.

I can have the block upstairs inside 30 minutes, and still catch Shrill O'Biley's Mail segment.

Surprisingly clean head and grungy exhaust gasket;

F3.26HeadExGskt.jpg (50.73 KiB) Viewed 6086 times

Piston crown before it was cleaned up with a soft brass brush:

F3.26PistonTop.jpg (69.86 KiB) Viewed 6086 times

Surprisingly cool-running piston side. (The bore looks even better!)

F3.26PistonSide.jpg (67.2 KiB) Viewed 6086 times

I was always careful to jet on the rich or Stupid Rich side, and it seems to show on the piston. Sides are silvery, not darkened. That coating of soot on the crown was maybe a half-mm thick. There was a good bit of softer stuff in the exhaust header, hinted at by the exhaust gasket's appearance. Fuel mix was a bit more oil than 32:1 - around 28 or 30:1 as I was slowly using up a can of 25:1 by adding a couple of quarts per 4-gallon fillup of the 32 stuff.

[Wheelman-111]

Greetings:

After those pics were taken, I reassembled with a new Corsa thin Alu basr gasket, O-ring and a fresh exhaust (VW) gasket.
Still had time and reasonably warm weather to reinstall the block into the framem

I discovered one of the barbs I installed on the CT manifold had worked a bit loose from pulling off the vac line a few times. Cemented it on with a dab of JBWeld around the threads to avoid a worsening vac leak. Put the pipe back on and went for an errand ride.
Ran really well despite 30-degree temps down here in Deepinnaharta.

Freezing rain forecast for the next 2 days so testing resumes next week.

[Wheelman-111]

Greetings:

Spring has arrived in Deepinnaharta. From mornings in the 30s to almost 60 now, I could no longer ignore how rich Flash was feeling. The power sag seemed to coincide with a variator shift that required a firm twist of the wrist to overcome. Linear? Not!
I stayed with the 52 but dropped the needle a click and swapped out the 128 for a 125 Main. (I know, I usually try to avoid making 2 changes at once...)
Temp gauge basically the same; 275 at part-throttle and 350 WOT, but it still kicks down a little when I chop the throttle -very reassuring - and the sloppy off-the-line sag is gone.
BTW I had another brief WOT opportunity on the ride home, totin' GPS. 66.4 seems to be reproducible @ 9750 RPM. What are the odds that a top speed run will result in exactly the same speed - to the tenth! - as my prior best-ever run? I'm almost certain it's still rich but reliability as a daily rider, not maximal output, is the goal.