Super 8 4Stroke 50 cc Big bore Max Speed

[bahiano]

Dear community,

having a problem with my 90cc BGM Big bore kit. Carb is still the factory one, main jet is a 98.
Now to my problem, the kit is not as fast as i hoped to. It goes 65 KM/H by GPS and that is far to slow, it ran the same with
my 50 cc kit with no restrictions.

Setup:
Naraku HS Variator with 6.3 grams
BGM 90 cc Big Bore kit incl. cylinder head with bigger valves.
Naraku Clutch

Carb is well adjusted and the plug looks perfect, acceleration is fairly ok, i just hoped for like 75 KM/H with factory carburator... don´t wanna go for a bigger one...


Your help would be highly appreciated as nobody here in Germany can really help me...


Regards from Germany Markus

[zombie]

I believe your issue is the carb. The bigger jug uses more fuel to make more power. You can only suck so much air thru a straw.

[bahiano]

You mean i should go for a bigger Carb or just modify air intake box (bigger hose to carb)?

[zombie]

You need at LEAST 24mm carb for 90cc's to run. 24mm is the smallest I would use. You can idel around all month on the oem carb but never get past 1/4 throttle. There is just not enough mix getting out of it. Modding the air box will surely seize your build.
http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=24mm+carb&_sacat=0
Try a cheap one to prove it.

[bahiano]

Thanks a lot Zombie! I will go for a 24 Naraku Carb...

[zombie]

That will end all your trouble. You will need to a buy a filter with it, or modify the air box to attach.

[bahiano]

Is there a HOWTO for the air box attach modification?
Greetz Markus

[zombie]

I'm sure youtube has something. But basically just adapt some hoses to the set up. http://www.partsforscooters.com/100-149_Intake_tube_gy6

[bahiano]

Thanks so much, i did it... bought a Naraku 24 CVK Carb and now it runs great!
As for the air intake, i just modified the hose to a bigger one... worked fine!

[zombie]

Congrats! Now you can raise hell with the big boys!

[ailixhomes]

You need at LEAST 24mm carb for 90cc's to run. 24mm is the smallest I would use. You can idel around all month on the oem carb but never get past 1/4 throttle. There is just not enough mix getting out of it. Modding the air box will surely seize your build.
http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=24mm+carb&_sacat=0
Try a cheap one to prove it.

Vehicle is very useful things for every one in this busy era. There are many online stores for shopping. Thanks for sharing this such useful information to here about super 8 4stroke.

[zombie]

anytime.