The bike now Idles perfect with the carb on the third notch! Much more responsive in mid throttle. The engine still 4 strokes now and then but It did help the over all performance. I used .75 mm or .0295in bit. I was surprised that I could just use my fingers and the drill bit. Just the slightest amount of material. This mod was done to my 48cc Grubee, slant head. I a run a E3.12 sparkplug. I have also port matched the gaskets and cleaned up and polished the chamber in the head. I can also reach my top speed quicker. Anyone else have success with this?
Went ahead and drilled the jet...
- Thread starter Neptunati
- Start date
Mac
New Member
Pretty much standard practice when tuning. Most engines will start out of the box, but ya never know what's lurking in the crankcase(metal shavings etc). I would go a bit smaller with the jet size. on my 80's, I used a #71, works for where I'm at (sea level) there is a whole thread on the jetting and sealing of the carb. Your on the right track!
Mac
Mac
Venice Motor Bikes
Custom Builder / Dealer/Los Angeles
# 71 bit usually does the trick! 