top end help

[HammahDIO808]

I need help on my high end.

72 contessa
44.4 ruima mini crank
Boost ported and match with bore,exaust and intake ported
Ct black
30oko, 138m 52p
Lighten mag
Ncy pulley, 42g weights
Ncy clutch, 3k clutch and 1500 center spring
Ncy clutch bell
Ncy torque plate
Zx trans
Fat teeth belt
6.9 gears
1st gen pg long
Koso fan


I weight 185lbs
My bike has a lot of bottom end. Feels like I'm tapping out to early. Wat can I do/change to have more top end?

I need my bike tunedd to almost/to its potential, becuz of people talking smack about them being fast with there 82 bores.

[Trafficjamz]

Try a 654 belt it might help top end

[Wheelman-111]

Greetings:

Unless you've ported the Cortessa to scream, that 30mm OKO is HUGE for your 77ccs. Consider a 24 or 26mm.

Even the higher-revving Corsa bore doesn't much exceed 11K in stock form. The Cortessa revs lower, hence "signs off" early. The gigantic intake probably doesn't help anything.

[HammahDIO808]

Ill try to get a 28 carb and see how it goes. And my contessa isn't ported as big.

[Wheelman-111]

Greetings:

Quoth HammahDIO808:

My bike has a lot of bottom end. Feels like I'm tapping out to early.

Frankly, I'm impressed that you could get that OKO 30 to produce any low-end. I had one early-on on a ministroked 90cc and never did get it to run very clean except at high-rpm and WOT.

I've got a 26 on my current Corsa/Stock Crank (True 72 cc) setup and am very happy with it. It may be the reason for a bit of top-end gain compared to the 24 I had before, and it's about as easy to tune. The 28 may be more unforgiving for part-throttle tuning. Then again it's a more popular size with lots of known "recipes" and fewer secrets.

No matter what pipe/intake/carb you install, however, port timing ultimately dictates the RPM range where the engine will make torque. Horsepower is higher if that torque comes on at faster RPM.

HP = Torque x RPM. There's no getting around it.

[topshottah 94]

split your block when you port
foreal thats why i got rid of my last arnada block
those little shavings get into your crank bearings and mess up your crank rotation
try a different pipe(scorpion,pg long,sef majik,arrow)
just tune,try whatever you bike wants

[HammahDIO808]

Yeahps I no dat shottah mohn.
My portings are all g. I only need help on tunning drive line and wat so ever.

[z50r-ghost]

2nd on the "30mm carb is HUGE for your 77cc application" noted by Wheelman.

I dropped from a 28mm OKO to a 21mm OKO, and absolutely LOVED the power delivery, smoothness, torque AND top end. Best $'s i spent for a really great upgrade... I think i *may* have been the 1st to go all the way down to a 21mm, which was a drastic jump; but i was really happy with it!

Wheelman has more tuning experience and some extensive time with BOTH the 26mm and 24mm, and prefers the 26mm...

Later, jon

[Wheelman-111]

Greetings:

The best speed I got with the 24 was around 66MPH. I got to 69.9 with the 26, but I'm not prepared to attest that the carb was the only reason, because I had made other small changes too. For all I know, it might be just as fast with the 21. For sure the smaller carbs are more forgiving of poor jet selection.

[kingkamehameha]

Cuz your weights are wrong. Cannont mix 5g and 9g weightts. Try 7s or 8s together.vdats your problem among other things. Try a smaller carb with 52 135 jets. Perfect hawaii combo

[Jahden]

king

so for weights, you can't go farther than 2 up or 2 down? just tryna learn more cuz I'm still a newbie

[kingkamehameha]

Can only mix weightts that are 2 grams apart at the most

[veedubh20]

28 mm Oko work well .

32:1. 48-50/ 140. Then work main jet down. N look at a plug color.

Get a 4k clutch spring n Light clutch

Just ped talk about 82cc 50mm can't afford buy polini or malossi rofl!
There are 7g equal to 42, 6/7 or 5/7.

[Mystic]

You can mix whatever weights work for you, I have seen 3s and 6s mixed

[kingkamehameha]

You can mix whatever weights work for you, I have seen 3s and 6s mixed

Mixing weights like tha makes for horrible tuning. I was told by a ffew knowlegeable guys thatt you can't mix past two numbers apart. Someone back me up on this