Hoping for some advice on head/carb combination
Current setup:
26" wheel
36T sprocket
49cc
Stock slant head with 2 gaskets from soda can
SKF main bearings
Stihl top needle bearing
RSE reed valve
Banana expansion
w/ stock exhaust's whole header (~20cm)
Custom CDI (kx/jag/ivanh/rohmell...)
CR80 coil (NGK non-resistor boot)
Offset intake 32mm
NT carb 80 jet
Cone air filter
Running NGK B7HS sparkplug
I'm getting 41mph maximum @ ~7000rpm
but only wish to cruise at like 30 flat. climb maybe 20 (which IS its current state).
Also, it starts and idles no problem
Intake port bored only at the entrance so that the reeds open freely (actual port timing is stock and so is exhaust's and transfers. No boost port)
My only issue is temperature. With a b7hs I'm getting around 370 degrees Fahrenheit. With b6hs was in the 400's. I'm getting a B8HS tomorrow and we'll see how it goes.. Either way plugs don't do miracles so it's high time I get a bigger head for cooling. And I'm thinking of a Puch head (https://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-comp-head-50cc.htm)?
So then my big question mark is I feel like I should go for bigger carb. I'm already at an 80 jet on the NT, puch head should be cooler and allow me to up compression a bit so it seems I should go bigger carb.. am I right. Still, I am unsure because of having reeds. So, in a scenario where bigger carb is beneficial would that imply bigger reed size also?? In other words, is fuel delivery limited by reed size?
If not, What size should I go? As I have read, reed-valved needs smaller carb compared to piston-ported and too big a carb will lead to low rpm issues. So I'm thinking a modest increase from 14mm of the stock NT to maybe 16mm?
I'm considering this guy pz16 (https://m.ebay.com/itm/KEIHIN-Japan...339593?hash=item1c9f28dcc9:g:qMQAAOSw05taZ2bN)
But then the most important thing, which range of jets to get?? Specially for the pilot jets which I have zero experience with. Anyone run carbs with pilot jets ob these engines?
Current setup:
26" wheel
36T sprocket
49cc
Stock slant head with 2 gaskets from soda can
SKF main bearings
Stihl top needle bearing
RSE reed valve
Banana expansion
w/ stock exhaust's whole header (~20cm)
Custom CDI (kx/jag/ivanh/rohmell...)
CR80 coil (NGK non-resistor boot)
Offset intake 32mm
NT carb 80 jet
Cone air filter
Running NGK B7HS sparkplug
I'm getting 41mph maximum @ ~7000rpm
but only wish to cruise at like 30 flat. climb maybe 20 (which IS its current state).
Also, it starts and idles no problem
Intake port bored only at the entrance so that the reeds open freely (actual port timing is stock and so is exhaust's and transfers. No boost port)
My only issue is temperature. With a b7hs I'm getting around 370 degrees Fahrenheit. With b6hs was in the 400's. I'm getting a B8HS tomorrow and we'll see how it goes.. Either way plugs don't do miracles so it's high time I get a bigger head for cooling. And I'm thinking of a Puch head (https://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-comp-head-50cc.htm)?
So then my big question mark is I feel like I should go for bigger carb. I'm already at an 80 jet on the NT, puch head should be cooler and allow me to up compression a bit so it seems I should go bigger carb.. am I right. Still, I am unsure because of having reeds. So, in a scenario where bigger carb is beneficial would that imply bigger reed size also?? In other words, is fuel delivery limited by reed size?
If not, What size should I go? As I have read, reed-valved needs smaller carb compared to piston-ported and too big a carb will lead to low rpm issues. So I'm thinking a modest increase from 14mm of the stock NT to maybe 16mm?
I'm considering this guy pz16 (https://m.ebay.com/itm/KEIHIN-Japan...339593?hash=item1c9f28dcc9:g:qMQAAOSw05taZ2bN)
But then the most important thing, which range of jets to get?? Specially for the pilot jets which I have zero experience with. Anyone run carbs with pilot jets ob these engines?