Hi, back in 2006 (it’s been a long build!) I bought the parts from you (XLint Performance) to build up this engine for my JBR Merlyn Honda, to rebuild the bike as near original spec as possible. I finally started her for the first time this weekend and all seems fine except maybe the carburation. I had a new Mikuni from you (XLint) as part of the kit but could you just refresh me on jetting & needle height etc., she seems to be running a bit hotter than I’d imagined so far, although I have only done a very gently heat cycle & run through the gearbox so far. The spec we arrived at is as follows-

Merlyn XL 450 motor built for frame 002

Engine Number : XL350E 2006546

Final Spec December 2005;-

JE Piston 86 bore.
Powroll new stroker Crank assy, 76.3mm stroke, gives 450cc.
Megacycle 127-40 Cam.
RPM x Stroke / 152.4 = Ft per Minute so RPM = FPM/Stroke x 152.4 = 7989 RPM safe, according to Powroll.

Ti valve caps, larger valves & matched springs.
Remanufactured Rockers.
Webster Gear Set & new selectors.
New Oil Pump.
Chamchain manual stopper.
HD Camchain.
HD Clutch springs.
Coated Bore.

Kind regards, Adam