Hello gentleman, so I have finally lost compression on my stock Hobbit, only getting 25psi on My
cornwell Tools Compression Tester.
So after tearing down the motor, the Piston head is scratched as well as the piston sleeve. While I’m this far in to my rebuild I’ve decided to do a complete overhaul and replace all seals and upgrade my internals to give me a little more Speed.
The bike has a PROMA Performance pipe on it
And a TJT Variator with Treats Rumpus plate
Everything else is Bone stock with Points ignition system
Here is everything I’m looking to get
So far please let me know if I’m missing anything
*The DR 70CC 46MM Kit
*The vm20 Mikuni Carb Kit
Comes with 22.5 Idle Screw
180 Main Jet
*The Stuffy Race Crank kit with seals and bearing
Here are the questions that I was hoping someone more experienced then me can answer
1) I have seen others recommend to start with a 17.5 Idle screw for the Mikuni Vm20 as the 22.5 that comes stock in the Mikuni Vm20 runs rough AND also to start at a 150 Main jet compared to the 180 the Mikuni comes with stock
I know every carb tubing Is different due to location and temps but the stock jets supposedly don’t cut it, someone correct me if I’m wrong please
2) I will be using the stock head which I have heard is okay for now until I buy a upgraded head for it will this cause any significant problems besides the head running a little more hot? Any head recommendations for the DR kit ?
3) is the stuffy race crank worth the price compared to using the stock crank with all the other upgrades listed? Or is the crank something I MUST Upgrade because the stock crank can not handle the other upgrades?
Any info is greatly appreciated thank you for you time.