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Re: Flash 3.2: 72cc Corsa!

Posted: Tue Sep 07, 2010 11:58 pm
by sanjuro
I prefer acceleration and mid-range more than topend. I'd go with the 8.44s first too.

Re: Flash 3.2: 72cc Corsa!

Posted: Wed Sep 08, 2010 12:01 am
by Wheelman-111
Greetings:

Fair enough, but why?

Re: Flash 3.2: 72cc Corsa!

Posted: Wed Sep 08, 2010 12:20 am
by bakaracer
the 8to1 gears will only give you maybe another 3-5mph topend. so if you maxed the 8.5to1 gears at 65 then the 8to1 gears will give you a 68 maybe 70mph topend on the flat and a bit faster on the down hill. what were you hitting with the 8.5to1 gears?

Re: Flash 3.2: 72cc Corsa!

Posted: Wed Sep 08, 2010 12:50 am
by sanjuro
The topend isn't as important since I do a lot of hill carving in Austin vs. WOT on long straights.

Re: Flash 3.2: 72cc Corsa!

Posted: Wed Sep 08, 2010 8:44 am
by Wheelman-111
Greetings:

Thanks for the input. I have the bigger -for-Ruckus Polini and Brand-X variators that do increase "Overdrive" in the belt cavity. Running 8.44s on both blocks. F3.1 Nikasil on stock stroke was over 10K RPM at a best-ever documented speed of 62. Ministroker 90cc touched 69 MPH but cratered the piston due to well-documented :oops: Wheelman folly.

I understand the big Corsa ports support torque at higher RPM, so both power and engine speed are available for higher top groundspeeds, but maybe 70 is asking a lot.
F3.2Corsa.jpg
F3.2Corsa.jpg (50.38 KiB) Viewed 5452 times
"Used" but remarkably unworn.
Installed, ready for shrouds.
Installed, ready for shrouds.
F3.1CorsaRF.jpg (78.38 KiB) Viewed 5451 times
143PSI before gauge leakdown.
143PSI before gauge leakdown.
F3.2CorsaComp143.jpg (46.43 KiB) Viewed 5447 times
Since I don't have an axle, and I do want to get the Corsa on the road, I'll follow your advice, dawgs. Not much pesky break-in to do, but some tuning. I'm putting the PG Long on it, and will probably leave the carb jetting alone. I'm expecting it to be a bit rich going from 86 to 72cc, but then again with the freer-flowing pipe and higher RPMs I expect to turn, the 50/125 might be pretty close?

Re: Flash 3.2: 72cc Corsa!

Posted: Wed Sep 08, 2010 11:11 pm
by sum-azn-kid
FINALLY! you got a corsa. haha. be careful with your jeting since the pistons are $$$ i love mine. til i seized it. too lean and crappy oil(motul 710 at 4.5oz:1gal). $135 for new piston from daywot. I hit a little over 60 maybe 65, uported and on sym block. i saw a af16 block and my boost port is tiny.... good luck

Re: Flash 3.2: 72cc Corsa!

Posted: Thu Sep 09, 2010 12:43 am
by veedubh20
125 main jet is to small, need to go bigger try 145 main, if plug foul, then go down main jet.
polin corsa w/ pg long- 32:1.

Re: Flash 3.2: 72cc Corsa!

Posted: Thu Sep 09, 2010 1:53 am
by bakaracer
veedubh20 wrote:125 main jet is to small, need to go bigger try 145 main, if plug foul, then go down main jet.
polin corsa w/ pg long- 32:1.
He is using a 24mm carb

Re: Flash 3.2: 72cc Corsa!

Posted: Thu Sep 09, 2010 1:08 pm
by Wheelman-111
Greetings:

Thanks, dawgs! Yup, 24mm OKO for now. Still working on 86cc Flash 4.2 for now. It seems to like to 48 Pilot better than the 50, but even that little 125MJ is too big, methinks. Full throttle better than before, but you can hear/feel the RPM and thrust decline as the throttle exceeds 3/4 full. It will run up past 45MPH pretty quick using only 2/3-3/4 throttle, but that main needs to come down a size. Fortunately I have a 122. :)

Re: Flash 3.2: 72cc Corsa!

Posted: Fri Sep 10, 2010 12:07 am
by z50r-ghost
Wheelman.... I am glad you jumped on that deal. You FINALLY crossed over into "Corsa" land! You will love the Corsa; mine has never let me down.

Laer, jon

Re: Flash 3.2: 72cc Corsa!

Posted: Fri Sep 10, 2010 1:58 am
by Trafficjamz
Doesn't the corsa bore have a smaller boost port than the nikasil bore?

How can you switch back once the boost port has been cut?

Re: Flash 3.2: 72cc Corsa!

Posted: Fri Sep 10, 2010 4:57 am
by elite_dub
I agree stick to the 8:4 gearing it does well enough

Re: Flash 3.2: 72cc Corsa!

Posted: Fri Sep 10, 2010 6:19 am
by Munstah666
Trafficjamz wrote:Doesn't the corsa bore have a smaller boost port than the nikasil bore?

How can you switch back once the boost port has been cut?
Never did ran into that situation, but I guess one easier way would be to enlarge the entrance(if your cut wasn't too excessive) port on the bore just enough to match the ports on block. The corsa should have enough metal to give.

Re: Flash 3.2: 72cc Corsa!

Posted: Thu Sep 23, 2010 12:22 am
by Wheelman-111
Greetings:

The corsa has the same 3x6mm boost port as the stock AF16 case. It went on the uncut case that previously housed the Nik, which also had the stock-sized boost port.

Spark plug threads repaired, :oops: the Corsa caught fire this evening. Jetting is wrong, but runs reasonably well. Variator and spring are Way wrong, but I'm liking its legs when it gets to about 25!

I left the 45/120 combo on the 24mm OKO, and the temps are cool, it smokes, a Lot, but the plug is too pale to read after 30 minutes' run time. I'm guessing it's rich based on these observations, but not positive. I leaned the needle one click to try testing manana.

Re: Flash 3.2: 72cc Corsa!

Posted: Mon Sep 27, 2010 9:30 pm
by Wheelman-111
Greetings:

Same 45/120 n the OKO 24. Ran errands tonight, packing GPS but no prolonged WOT because I'm still studying the plug color. Max temp seen at part-throttle cruising at 45 was 350 and not a hair above.
Plug still a dark chocolate color during this refreshing cooler weather, high 70s.

Garmin-girl said 58.5 in a very short romp down the (45 MPH) service road. No wind, no hill assist. This thing is effortlessly fast!

Needs 8:1 or possibly 7.5:1 gears not to exceed 10.5K RPM, despite Giant 97mm front variator on 669 belt.