All 48cc pistons that I have seen or bought have been flat top, except the old grubee gt2b which has a slight dome and a squish band on the head. What I've done on the flat top piston engines is to deck the cylinder till the piston is near the deck height and then sand the head down to raise compression.
New here! 50cc build
- Thread starter Atvrunner2
- Start date
Risk Man
Well-Known Member
it does look too oily. i am using Damien 32-1 mix with Amsoil Synthetic oil
Risk Man
Well-Known Member
I had moved it up in the beginning as it was way too rich. After about 40 miles I changed the plug and the old one looked pretty grey. Had not checked it until this and it does look a bit black. Thanks.
This may not apply to the newer carbs but on the nt the stock jet has always been too rich, I'm at about 900 feet above sea level. My avatar bike has a nt with the jet soldered and drilled with a #73 bit. Stock the jet was a #71 bit size. I get the wide open throttle jet size correct first, then adjust the needle position for low to mid range.
Karl Snarl
Well-Known Member
The Bofeng uses the same size jet, but is way better at atomizing. Here a stock runs well on a 68-69 jet in the old speed and NT carbs. The new Bofeng, I'm down to a 60 jet on a stock engine. INSANE!! Was still pig rich at 65. Haven't tested the 60 yet, tank leaked AGAIN!! I'm at about 2200 feet or so.
Chop-chop
Active Member
- Local time
- 11:28 PM
- Joined
- May 19, 2021
- Messages
- 184
By the sounds of it, u should try that 60 jet.
Similar threads
- Question
