Scott,
Maybe it's the air valve that is easiest to move has the problem not the one
with more resistence. It could be that the o-ring in the front air valve
needs to be replaced. There's an o-ring on the needle adjusting screw that
is inside the air valves. This is assuming that you have carbs with
adjustable needles. I'm not sure how ZS carbs on a TR4 are adjusted for
fuel mixture so this may not apply. On my ZS carbs that o-ring holds the
damper oil in the air valve so it doesn't leak out and get into the fuel
mixture. Does your front air valve hold damper oil or does it disappear
quickly? How bout the back one? One better than the other?
If you have a bad o-ring in that front air valve then it might explain the
symptoms you described....your rear air valve has more resistance than the
front with the dampers in but not with them out (cause the air or oil gets
pushed out where the o-ring should be stopping it). Swapping dampers
doesn't change the problem (cause the bad/missing/cracked o-ring is still in
the front air valve). And that the air valve and dampers don't drag on
anything (cause it's the difference in pressure release not drag that's the
problem).
Now this applies only if both air valves start out with the same levels of
oil or air (no oil) in both...they're both fluids when you're comparing lift
of the air valves or pushing the damper down into the air valve so it's a
matter of comparison when your fluid density is equal in both. Given all
that, it seems to me like you have a leak in your front air valve dampening
system if the pressure/resistance is different and that means o-ring.
You can replace the o-rings...at least I can on my 1971 ZS 175 CD-2 carbs.
The o-ring size is 2-010, call your local gasket/o-rings/seals place or you
can call mine (Rocket Seals in Denver 303-777-7024...NFI) and tell them you
want that size in Viton which is a oil-resistant compound of some sort and
lasts a little longer than plain rubber. To get the old o-ring out take a
long skinny punch (I've even used a pencil but they WILL splinter and jab
you in the hand...not that I'VE ever done that) and drive the needle
adjusting screw out the top of the air valve (of course you've removed the
needle first). There's a star washer that holds the adjusting needle screw
in place so make sure you cover the top of the air valve with a rag or
you'll be chasing that star washer around the garage floor. Put the new
o-ring on and reverse instructions (as Bentley says). You can use your
punch to make the star washer go back in and sit down flat on the needle
adjusting screw. Be gentle but make sure the adjusting needle valve and
star washer are flush to the bottom of the air valve.
As far as the car running roughing when you moved it. If you've been
pushing/leaking damper oil (gee List I wonder what the best damper oil might
be????) into the engine past that bad/missing/cracked o-ring maybe it fouled
a plug or two. But then again that's just a guess too.
Hope this solves your problem. But if not maybe some leaky damper o-rings
will get fixed which should improve your acceleration.
Good Luck
Bud Rolofson
71TR6 CC57365 (Good 6)
66TR4A CTC57806 (The Wreck-Almost Parts)
66TR4A CTC57529 (The Project)
----- Original Message -----
From: "Scott Tilton" <sdtilton@yahoo.com>
To: "BOB KRAMER" <rgk@flash.net>
Cc: <triumphs@autox.team.net>
Sent: Tuesday, January 15, 2002 9:41 AM
Subject: Re: TR-4 Stromberg Piston update (long)
> Hey Bob . . (et all)
>
> Thanks for the reply . . those sound like good techniques.
>
> I might want to clairfy the symptoms.
>
> I haven't swapped the "pistons" meaning the air-valve diaphragm assembly.
>
> They seem to move up and down in their carb bodies just fine.
>
> When I install the dampers (the little rods that screws in the top of the
> carbs) . . . then one carb has more resistance to in the air valve piston
> moving upwards.
>
> It doesn' matter if I swap the dampers (little rod that screws in the top)
> between carbs .. . the rear carb always has the harder piston to move.
>
> The restricted movement is most defintely related to dampening effect and
not
> the air valve or the needle dragging on anything.
>
> Thanks for your replies.
>
> Scott
> --- BOB KRAMER <rgk@flash.net> wrote:
> > I haven't paid any attention to this thread so forgive me if I cover old
> > ground. If the pistons are doing the same thing after swapping, i.e.;
when
> > you moved the piston the problem moved, than check to see if the needle
is
> > straight. You can also wipe a little lithium grease inside the bore as a
> > telltale to see if the piston is rubbing. If you find it cocks to one
side
> > diagonally when lifted, it may be too small.
> > Bob Kramer
> > rgk@flash.net
> > ----- Original Message -----
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