Although TerriAnne has a very helpful Rochester page (among many) on her site,
I will recount my experience. I have a 1975 SIII 109 2.25 RHD (UK style). It
was equipped with a Zenith with the adapter base. I used the single barrel
30.9 venturi, manual choke B model Rochester recommended. It came equipped
with a #51 jet. Over here I was able to source a brass insert with a gradiated
nozzle for hose to install in the vaccum port, and another brass insert for
the gas to go in. The carb didn't come with these so get those before you
leave the store if they are not there. Jets are very easy to access, just
remove four screws on the cover. No linkage to fiddle with to get the cover
off. The jet is very tiny but easily recognizable, and if you have Superman
vision you may see the number stamped on it. I removed the Zenith, and left
the phenolic block that sat under the adaptor in place. I removed the metal
cylinder that fits inside the phenolic block. I didn't have a Rochester block
or gasket handy so I cut two myself out of thick gasket material and installed
them between the phenolic block and carb, careful to make a passage for the
little hole at the base of the Rochester-again as TerriAnne helpfully pointed
out. The bolt holes are a tad narrow, so I rushed down to my local machine
shop to have those lengthened a bit over lunch. Once that is done it just
slips on the studs like it was made for it. The air cleaner tube fits right on
with no problem. Now the problem is that the Zenith lever pulls downward to
accelerate, but the Rochester pulls up. Here is the solution. Remove the
linkage. Take off the bell-crank (terminology?) by removing the bolt that
holds it to the inner fender or whatever. Remove the long lever and the short
lever and flip them around so that when installed the long lever will be
pointing to the firewall. What you want it to have it do is push up on the
short linkage gizmo so that it is a straight shot to push up the lever. The
two tabs on the long lever must be bent the other way to enclose the short
lever just as it did when installed the right way. Reasemble with the spring,
inner spindle, washer, and cotter pin, reinstall. Spin it around so that it is
pushing pretty much straight up on the Rochester lever, and tighten the nut.
The short linkage gizmo (name?) will have to be adjusted, I think shortened in
my case. The other long rod worked just fine. You may also need to adjust the
arm on the long rod (perhaps on RHD only) that connects the pedal action to
the linkage action, but that is easy. Here is a tip I discovered. If the
little ends that stick out of the gizmo are gunked up or if they have been
adjusted too tight they will cause the linkage action to hang up enough so
that on return from acceleration it may not go all the way down to idle. The
trick for them is to have them loose enough to spin freely, but not loose
enough to fall or be pulled out.
To sum up:
Get the right carb-British Pacific and TerriAnn have helpful pages on id'ing
the right model. 30.9mm venturi!
Widen the base holes to fit.
Remove adapter, Keep phenolic block, remove metal cyclinder. (assuming
previous Zenith installation)
Use a gasket or two between carb and phenolic block. Be careful that tiny hole
in carb base is not blocked.
Take the bell crank off, flip the levers around, bend the tabs that enclose
the short lever in opposite direction so they will enclose it as before.
Reinstall and spin till you have it so that it will push the Rochester lever
straight up.
Connect your linkage, gas line, vacuum hose, and air cleaner assy, and that's
it. Can be done in under an hour easy. Is much easier with adequate lighting
and no mosquitos, but can be done without good lighting and being bitten to
death.
If I have stated anything inaccurate, just plain wrong or left anything out
please jump in!
Regards,
John
_______________________________________________
LRO mailing list
LRO@land-rover.team.net
http://land-rover.team.net/mailman/listinfo/lro
This archive was generated by hypermail 2b30 : Wed Jan 08 2003 - 06:39:38 EST