Mod Runner for 2stroker enthusiast.

[uevoli]

Extracted from: Eric Gorr's Forward Motion

 

REED VALVE

 

Think of a reed valve like a carburetor, bigger valves with large flow-areas work best for high rpm power bands. In general, reed valves with six or more petals are used for high rpm engines. Reed valves with four petals are used for dirt bikes that need strong low end and mid range power. There are three other factors to consider when choosing a reed valve. The angle of the reed valve, the type of reed material, and the petal thickness. The two common reed valve angles are 30 and 45 degrees. A 30-degree valve is designed for low to mid rpm and a 45 degree valve is designed for high rpm. There are two types of reed petal materials commonly used, carbon fiber and fiberglass. Carbon fiber reeds are lightweight but relatively stiff (spring tension) and designed to resist fluttering at high rpm. Fiberglass reeds have relatively low spring tension so they instantly respond to pressure that changes in the crankcase, however the low spring tension makes them flutter at high rpm thereby limiting the amount of power. Fiberglass reed petals are good for low to mid power bands and carbon fiber reeds are better for high rpm engines.

 

Boyesen Dual Stage reeds have a large thick base reed with a smaller thinner reed mounted on top. This setup widens the rpm range where the reed valve flows best. The thin reeds respond to low rpm and low frequency pressure pulses. The thick reeds respond to higher-pressure pulses and resist fluttering at high rpm. A Boyesen RAD valve is different than a traditional reed valve. Bikes with single rear shocks have off-set carbs. The RAD valve is designed to redistribute the gas flow to the crankcases evenly. A RAD valve will give an overall improvement to the power band. Polini of Italy makes a reed valve called the Supervalve. It features several mini sets of reeds positioned vertically instead of horizontally like conventional reed valves. These valves are excellent for enduro riding because of improved throttle response. In tests on an inertia chassis dyno show the Supervalve to be superior when power shifting. However these valves don't generate greater peak power than conventional reed valves. Supervalves are imported to America and sold by Moto Italia in Maine.

[sheep]

Extracted from: Eric Gorr's Forward Motion

 

REED VALVE

 

Think of a reed valve like a carburetor, bigger valves with large flow-areas work best for high rpm power bands. In general, reed valves with six or more petals are used for high rpm engines. Reed valves with four petals are used for dirt bikes that need strong low end and mid range power. There are three other factors to consider when choosing a reed valve. The angle of the reed valve, the type of reed material, and the petal thickness. The two common reed valve angles are 30 and 45 degrees. A 30-degree valve is designed for low to mid rpm and a 45 degree valve is designed for high rpm. There are two types of reed petal materials commonly used, carbon fiber and fiberglass. Carbon fiber reeds are lightweight but relatively stiff (spring tension) and designed to resist fluttering at high rpm. Fiberglass reeds have relatively low spring tension so they instantly respond to pressure that changes in the crankcase, however the low spring tension makes them flutter at high rpm thereby limiting the amount of power. Fiberglass reed petals are good for low to mid power bands and carbon fiber reeds are better for high rpm engines.

 

Boyesen Dual Stage reeds have a large thick base reed with a smaller thinner reed mounted on top. This setup widens the rpm range where the reed valve flows best. The thin reeds respond to low rpm and low frequency pressure pulses. The thick reeds respond to higher-pressure pulses and resist fluttering at high rpm. A Boyesen RAD valve is different than a traditional reed valve. Bikes with single rear shocks have off-set carbs. The RAD valve is designed to redistribute the gas flow to the crankcases evenly. A RAD valve will give an overall improvement to the power band. Polini of Italy makes a reed valve called the Supervalve. It features several mini sets of reeds positioned vertically instead of horizontally like conventional reed valves. These valves are excellent for enduro riding because of improved throttle response. In tests on an inertia chassis dyno show the Supervalve to be superior when power shifting. However these valves don't generate greater peak power than conventional reed valves. Supervalves are imported to America and sold by Moto Italia in Maine.

 

That sorta wad i meant but super summarized for quick and easy reading.

[hors3m3n]

Just helping a fellow fren promote his services..

 

RIDE FAST & LOOK HOT!

u gotta ride fast n look nice n clean at the same time..

dirt, carbon, grease n wat nots can cause extra weight lowering ur speed n may affect ur stability.. so the solution is........ wash ur bike often!!

 

D'GAPZ is doing a bike wash that specializes in:

 

Detailed washing

Waxing

Polishing

Chain cleaning

 

Currently we're located at 2 places :

 

123 kaki bukit ave 1,shun li industrial estate.

behind republic motor. Timing is from 12noon to 8pm. Monday to saturday only. Sunday closed.

 

Tampines st 72, Blk 723a mscp level 2.

Timing is from 9pm onwards to 1 am. Monday to saturday only. Sunday closed.

For this location,by booking appt only.

 

For booking and more enquiries, do call Rudy at hp: 8400-3867

 

You can also view us at http://www.dgapz.multiply.com

 

Hope to hear from you guys soon..

 

Support Local Talent

[botak690]

just wondering..

 

high compression = faster pick up?

 

u still ride 2t?

[hors3m3n]

u still ride 2t?

 

yup.. 2t vespa..

[TS1]

Just helping a fellow fren promote his services..

 

RIDE FAST & LOOK HOT!

u gotta ride fast n look nice n clean at the same time..

dirt, carbon, grease n wat nots can cause extra weight lowering ur speed n may affect ur stability.. so the solution is........ wash ur bike often!!

 

D'GAPZ is doing a bike wash that specializes in:

 

Detailed washing

Waxing

Polishing

Chain cleaning

 

Currently we're located at 2 places :

 

123 kaki bukit ave 1,shun li industrial estate.

behind republic motor. Timing is from 12noon to 8pm. Monday to saturday only. Sunday closed.

 

Tampines st 72, Blk 723a mscp level 2.

Timing is from 9pm onwards to 1 am. Monday to saturday only. Sunday closed.

For this location,by booking appt only.

 

For booking and more enquiries, do call Rudy at hp: 8400-3867

 

You can also view us at http://www.dgapz.multiply.com

 

Hope to hear from you guys soon..

 

Support Local Talent

 

can cLean timing chain or not? heh

[botak690]

yup.. 2t vespa..

 

nvm then......no point if i explain.....

[hors3m3n]

nvm then......no point if i explain.....

 

y not? compression is the engine and 2 stroke engines work the same way right?

 

and also prob others out there mite wanna know abt their 2stroke oso..

 

so pls share ur wisdom..

[hors3m3n]

can cLean timing chain or not? heh

 

hmm.... loya buruk pulak budak ni...

[g str]

another question frm me..

 

Wats the diameter for the original carb...?

 

Wat u gain using Mikuni 24mm..? (i undastand its bigger)

if u can get the same acceleration n top speed using the original carb..

anione can explain..

thks..

[hors3m3n]

with proper tuning n setting of course can get better pick up n top speed.. if not why they make..

but other parts play a part too in improving it.. mine only gain better pick up.. top speed around the same.. coz i lazy to keep do the setting of jets n stuff.. have to b patient n keep testing out..

[CONTROVERSY]

The reed valve topic is solved.. Thanx bro for sharing tis solid info..

[CONTROVERSY]

another question frm me..

 

Wats the diameter for the original carb...?

 

Wat u gain using Mikuni 24mm..? (i undastand its bigger)

if u can get the same acceleration n top speed using the original carb..

anione can explain..

thks..

Original carb is 19mm if i'm not mistaken.

 

By using original carb uses less airflow from e mouth and

Smaller end diameter so e power wont go extend or beyond

Bigger carb. The bigger e carb is, the more Power u get

Provide that u get e right setting of course. Try an error is a must.

 

So what's e point if carburator companies invent a bigger carb

But produces the same power as smaller carbs.

 

P.S: becarefull when using stock carb especially when

Revving full throttle for a distance. Your piston may jammed

For insufficient gas.

 

This is my point of view.. Tried n tested.

[Sesshou]

the pwk28 carb work well on the sp. but need to change the needle to a richer one if not will run lean

[CONTROVERSY]

the pwk28 carb work well on the sp. but need to change the needle to a richer one if not will run lean

True.. Good pickup but no top end.

[CONTROVERSY]

Mikuni TMX, Koso PWK & Uma (local) carburator have

Special features eg. POWERJET. This little thing can give

extra boost Like a reserve M/jet helping each other for

Certain high revv. It will activate when u reach mid to

End. I guess this invention is superb for speed hunger.

 

Anyone knows about this carbs, feel free to share your info.

[Sesshou]

mukuni produce a power jet set. i bought and install on my TM carb last time. But the kit can't get locally. i think there's a formula for the jet calculation when using power jet ....can't remember how many percent

[Sesshou]

True.. Good pickup but no top end.

 

 

ya that's true. but 2 stroke should go for monster pick up:angel:

[CONTROVERSY]

mukuni produce a power jet set. i bought and install on my TM carb last time. But the kit can't get locally. i think there's a formula for the jet calculation when using power jet ....can't remember how many percent

Dat means u really sacrifice your TM carb..

[CONTROVERSY]

Hoping to hear more info from other users that tried n tested..

[g str]

Mikuni TMX, Koso PWK & Uma (local) carburator have

Special features eg. POWERJET. This little thing can give

extra boost Like a reserve M/jet helping each other for

Certain high revv. It will activate when u reach mid to

End. I guess this invention is superb for speed hunger.

 

Anyone knows about this carbs, feel free to share your info.

 

*Uma racing - POWERJET

true, supply extra fuel for extra boost..

so far its good on 4stroke.. try n tested on Yamaha spark135 n x1r.

even Tuas circuit riders are using it..

on 2stroke still not sure.. need to ask ard abt it..

 

can possibly purchase it at JB (lor bapok)

comes in 24mm, 28mm, 32mm, 34mm

tag along wif a set of jets so its easier for u to tune it.

[DeZewL]

can possibly purchase it at JB (lor bapok)

comes in 24mm, 28mm, 32mm, 34mm

tag along wif a set of jets so its easier for u to tune it.

 

setting kampong.....

[CONTROVERSY]

*Uma racing - POWERJET

true, supply extra fuel for extra boost..

so far its good on 4stroke.. try n tested on Yamaha spark135 n x1r.

even Tuas circuit riders are using it..

on 2stroke still not sure.. need to ask ard abt it..

 

can possibly purchase it at JB (lor bapok)

comes in 24mm, 28mm, 32mm, 34mm

tag along wif a set of jets so its easier for u to tune it.

Should test it on 2stroke. Heard "Jacky Turbo" fixed UMA racing 28mm on his bike. Maybe can ask him abt the result. I'm very particular abt sparkplug burning color.

[CONTROVERSY]

Maybe I should ask him personally.. Hope he's not busy at his workshop.

[boostron]

Should test it on 2stroke. Heard "Jacky Turbo" fixed UMA racing 28mm on his bike. Maybe can ask him abt the result. I'm very particular abt sparkplug burning color.

 

I asked a Johore fren of mine to get this UMA 24mm carb for me.. im gonna try it on my ride and i'll update u guys..