I think that the key is keeping the tolerance tight enough to maintain a seal
with the gas/oil in the piston grooves. Looks like somewhere between 3 and 6
thousanths clearance that quits working. It does not take much sanding on
aluminum to remove that much.
keith
>
> Since I have always had Solexs on my 67.5, I have no experience with
> Hitachi, but prior to the roadster I had plenty of experience with SUs on a
> variety of English cars; H2s, H4s, H6s, HD4s and HS4s, that covers 1.25,
> 1.5, and 1.75" bores. And for what it's worth, juggled lots of needles and
> pistons and never had a problem. Of course, never used sandpaper, sometimes
> a bit of emery cloth, but that was it.
>
> Jerry Krakauer
|