TR2/3/3A Rebuilt SU Carbs - Car Won't Start

[jfarris]

1956 TR3. I purchased a set of SU H6 carbs from a forum member months ago. They were rebuilt by a very reputable carb guru, but sat on the shelf for a couple of years. Today is Saturday, so I couldn't call the rebuilder and ask any questions. I put them on today and can't get the car to start. I am only getting fuel to the front carb. My old ones had banjo fittings, the new ones just have tubes in and out of the top of the bowls (see picture).
Thanks in advance for your help!

Question, does the front carb have to fill the float chamber before fuel is routed to the rear carb (see Pic). The inlet and outlet appear to be a straight pass through.



I did manage to get enough fuel in the front carb to have a leak. It is dripping out the bottom of the center of the jet spring, clamping screw, and actuating lever.
Question - how do I diagnose this and fix I'm guess old dry seal?)? Is there anything to tighten.

 

[M_Pied_Lourd]

Hi Jim,

Are you sure that you have the manifold installed on the car properly? It is very easy for the manifold to get hung up on the studs. If this happens you will get a no start situation and the carbs will not draw fuel properly.

Just a thought

Cheers
Tush

 

[jfarris]

Tush,
Long time, no hear from the Pack. I've kept up with your projects on several forums. I didn't change the manifold, just the carbs and they appeared to fit well on the existing manifold. Choke and throttle linkage actually fit and operate better than the previous carbs.
Thanks,

 

[TR3driver]

IMO the only cure for that leak is to replace the seal. You might get it to seal temporarily by soaking the cork in oil, but you'll have to disassemble to do that anyway, might as well change the seal. Moss sells some nitrile O-ring seals that last much better (in my experience) than the original cork ones do.

Don't be tempted to stretch the spring inside to put more force on the seal. It will mess up the choke action.

Edit: The front carb does mostly fill up before the rear one. Not sure why, must just be less resistance to the flow.

 

[Brinkerhoff]

If you aren't getting fuel to the rear carb. perhaps the needle in the float bowl lid is stuck shut from sitting.

 

[Scot1966]

Moss sells some nitrile O-ring seals that last much better (in my experience) than the original cork ones do.

Hello Randall, I have had issues with a leaking cork carb gasket from time to time. Maybe I'm not looking in the right place on the Moss site, but the carb diagram only shows cork #(97) ? Maybe I'm missing something ? I would like to give the nitrile gaskets a shot if I can find them.

 

[TR3driver]

It's actually just a standard size O-ring. I forget the size offhand, but I found them in my HF O-ring assortment.

Moss P/N is 365-420 "O-RING (leak-free replacement for #295-200)"

 

[jfarris]

I temporarily gave up and put the old carbs back on, car ran well, still can't get them to idle below 1,600 RPMS. I'll talk to the rebuilder about the float valves, order some parts, and try again.
Thanks for all the help!