ninjette.org - View Single Post

jkv45 · April 3rd, 2015, 07:09 PM

Swapped the standard bolts and crimp plates for some buttonheads with internal star washers for a cleaner look -

We also discovered that it's a factory 75cc engine and not the standard 50. The 75 has the same bore but a longer stroke. I was pretty sure from the sound and the power that it wasn't a 50.

Working on modifying the intake manifold to smooth the transition from the carb. Turns out it's not as easy as I'd hoped, as the external dimension of the intake manifold where it meets the carb is not as large as the carb. If you bored it out to the same internal size as the carb (24mm) the wall thickness would not be adequate and it would fall apart. For now we are transitioning it as smooth as possible, and making a bushing that will fit between the carb and the manifold to fill the 2mm x 2mm step between them. Also will open the backside up as much as possible and get a more gentle radius to the edge where the manifold joins the reed cage.

April 3rd, 2015, 07:09 PM	#15
jkv45 Rev Limiter Name: Jay Location: WI Join Date: Jul 2013 Motorcycle(s): '06 SV650n, '00 Derbi GPR, '64 CA77 Dream 305, '70 CL450 Scrambler, numerous dirt bikes Posts: A lot. MOTM - Jun '18, Oct '16	Swapped the standard bolts and crimp plates for some buttonheads with internal star washers for a cleaner look - We also discovered that it's a factory 75cc engine and not the standard 50. The 75 has the same bore but a longer stroke. I was pretty sure from the sound and the power that it wasn't a 50. Working on modifying the intake manifold to smooth the transition from the carb. Turns out it's not as easy as I'd hoped, as the external dimension of the intake manifold where it meets the carb is not as large as the carb. If you bored it out to the same internal size as the carb (24mm) the wall thickness would not be adequate and it would fall apart. For now we are transitioning it as smooth as possible, and making a bushing that will fit between the carb and the manifold to fill the 2mm x 2mm step between them. Also will open the backside up as much as possible and get a more gentle radius to the edge where the manifold joins the reed cage.