• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Ready to pull my hair out...

Share this page

G

gregsdrums

Senior Member
Offline
Here's my story. I purchased a 72 1275 that had sat in storage for 16 yrs. Drained fuel tank, flushed lines,changed filter, changed all fluids, changed dist. cap, rotor, spark plugs, wires, oil, filter, installed carb kits (2), checked compression- front to back- 135-130-125-125, pistons and cylinders looked good, although it does smoke. Front three plugs are clean and the rear one is black. Had valve job done, installed another intake manifold as the one that was on it was cracked. It will start and run for a while and sounds good. Then it will die and I can't get it re-started. You can smell the gas and hear the electric fuel pump running. Plugs are then wet. I can stick my finger in either carb and it comes out wet. Certainly looks to me like way to much fuel. I bench set the carbs by directions I got from a fellow forum member who has worked on little british cars for 40 years. When I push the car back in the garage there was a wet spot (looks like gas and oil) underneath it where it had run out of the exhaust manifold. I greatly enjoy these little british cars as I have two others (76-79)which only have one carb and they didn't give me near the headache this one has. Any suggestions would really be appreciated. Thanks in advance.
 
SWounds like stuck/bad float or too much fuel pressure. Check the oil to see ifit smells like gas and change it if it does or you'll burn it up.

How much fuel pressure you got, running a reg?
 
Sounds like either a float or sticking jet issue. Pull the cover off the float bowls and have a look.
 
Thanks for the reply. Don't know what kind of pump PO put on it and it doesn't have a reg. Changed oil early this afternoon and it did smell like gas. Was real thin also. Don't know about the fuel pressure but do know the return to the charcoal canister was leaking out the overflow onto garage floor. Did notice when I rebuilt carbs that the haynes manual showed a tab that you bend to adjust but these carbs don't have that tab, the floats are just hanging. Are they missing a piece?
 
floats should hang - they close as the fuel increases and they "float" higher - like a toilet tank. you can check by blowing in the intake while you "close" the float (bring it closer to the lid) at some point you shouldn't be able to blow anymore.
 
Try this, take the carburator dashpots off, remove the the dampner spring and pistons, now then move the key to the on position, which should activate the electric fuel pump, look at down the jet the fuel should be visable just below the top of the jet, if fuel is coming out the jets, then it's a bad float, needle/seat valve or too much fuel pressure. If the PO has installed a aftermerket fuel pump is could be regulated too high for your car, we only need like 2-3 psi of fuel pressure, you can buy cheap Purolator inline fuel pressure regualtor, it has big chrome dial on it with numbers that reflect the pressure amount, they are cheap, and seem to work fine (seen them a kazillion race cars over the years).

I check for bad float by submerging them into a bucket of water and looking for bubbles, I seldomly find a bad one.

Of course you can check the needle and seat valve for being stuck, by simply removing the float bowl lid and inspecting by moving the flaot up and down by hand and doing the blow test.

I would turn the engine over via battery power, with the plug out to make sure you pump out any gas lying on the piston tops, clean or get noew spark plugs.
 
In addition to everything already mentioned by others, it sounds as though you have the later, plastic moulded floats. These floats do not have the metal tab used for adjusting the float. You must shim the needle seat to set the float height. Moss published this supplement that addresses the plastic floats: Plastic Float
 
You are correct. They are the plastic moulded floats. You guys on this forum are just great. I can't express how much I appreciate all the suggestions/answers. It makes life so much easier when you have guys like yourselves that are willing to take the time to discuss answers to questions/problems as you've been there already and done that. Thanks again.
 
As usual I got 5 bucks that says stuck floats.
 
Jack

You gotta be giving odds on that bet :wink:

Pat
 
Foot, the only reason I make the offer is to make the point. Is about the only thing that goes wrong with SUs after setting a bit.

Fix just might take 5 min if you want to clean up the spill as well.

LOL
 
I don't know about the bets guys but I just took the carbs apart and both floats look good and free. Going to get a fuel pressure regulator now...
 
Not the float, the needle valve that the float pushes up, is it stuck in the down position?
 
Back
Top