This motor is another spec close to my own GT 250 using the same crank which consists of an RD 115 conrod on 60 webs with an eccentric pin making it 62mm stroke. The Kawasaki H2 piston requires a 115 rod as it has a low 30mm deck height.
This GT 250 conversion consists of:
Un-bridged GT 200 barrel bored to 71mm and ported
Wossner H2 71mm Piston
62/115 crank
LI 150 gearbox at 4.7 final drive
Fran race exhaust.
30mm BHPH carb
Kheper fully programmable ignition
Crankcase work
Mag transfer
Marking where the mag needs more taking out.
Crankcase
Cutting the trench for the big end on the 62 stroke.
Marking up
Marking where to cut the case transfers
Mag transfer
marking where the mag needs more taking out.
Crankcase
crankcase cut and crank in.
Transfer bases
checking the transfer base alignment between case and barrel.
barrel work
BDC
Checking port alignment at bottom dead center.
Cleaning up
Taking the thin areas out.
Marking
Marking how high the boost ports need to be.
Exhaust port
First rough cuts
Measuing
Checking the port positions with a depth gauge.
Exhaust port
Getting there
Chamfers
In this image its possible to make out the chamfers on the ports
Exhaust port
Nearly finished
Marking up
Marking where to cut.
Piston mods
Piston
Marking the reed window.
Piston mods
Cutting the reed window and arce.
Piston mods
Marked up again for final cuts
piston mods
The H2 piston skirts dont work well with a lambretta barrel layout and as such need reshaping.
Head work
Head
Cutting the squish band.
Head
Working the head volume.
Head
Re-profiled to piston crown and squish reworked
Squishing
4 point squish check.
Head
Squish check after head rework
Squish check
smaller on the edges which effects squish velocity.
Head to barrel
Checking alignment after head re-profile.
Miscellaneous
Exhaust stub
opening the stub
Combustion chamber volume
Using light oil to measure the head volume CC to check the compression ratio.
Port timing
Checking timing with dial gauge.
Timing
Various timing marks for checking the Kheper advance retard ignition system.
Torque
Torquing the head down.
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