start up and run after total rebuild

[Lorna c]

ok I have a roadster again had one in the 80s .. I'm am no mechanic so bare with me .. somehow I got this motor assembled myself BUT it starts and runs great until it's warm .. now it smells of gas and won't fire . backfires bad once usually from tailpipe if I keep it going past cold (no sensor on this car) I can start it six times while it's in cold and it will idle high and then if it's warmed up it will not start again it just turns over if I run it past cold and have it on and it warms up that I will raise up and when I turn it off there's a big backfire and it won't start again until it's cold I haven't forced to start up when it won't fire over and it smells of gas you taste it ,that heavy. can the timing be so far off its this rich ? I'm told not to mess with carbs because they should be set .. sooooo if I dial down the distributor to make it idle more on the normal side it seems to be ok until I turn it off and then it won't start up until I put the distributor back to the way it was and it seems to only way of fire up with this one settings and then once it's warm it's running so high idol, either I turn it down and it won't start up again or if I leave it high then turn it off it backfires and won't start up again.. what else do I look at ,I have not been able to time it yet because I'm told you're supposed to time it warm and when it's warm I'm afraid it's going to explode because the gas fumes are so heavy

[nismou20]

Idle should not be done by adjusting the distributor engine timing. Who told you carbs are in tune and not to be messed with? I would seriously consider getting your hands on a timing light to get the engine close to specs first. It may be running lean with idle so high. Backfiring could be a lean condition as well but mostly while running.

[Gregs672000]

Post your location, as a local owner may be able to help you. Smelling fuel could be a stuck or sunk float in one of the carb float bowls, located next to the carb itself. We need to know a lot more about your engine: 2000 or 1600? Year? Smog or de-smogged? We are happy to help!

[FairladySPL]

Lorna please be especially careful about the gasoline smell.

There are overflow fixtures on the bowl housings alongside the SU carbs that can, indeed, overflow when they feel like it. The gasoline is supposed to go out a small metal drain tube on the top of each bowl, and exit past the frame somewhere low, but those pipes often break off, which leaves the gasoline spewing very close to the exhaust manifold.

(You ask: What could possibly go wrong?)

[dbrick]

Sounds to me like it's running very rich, either stuck floats, stuck choke or just plain way out of adjustment. As soon as it warms up, it's way too rich, loads up backfires and stalls. Set the timing to the right setting either static, which might be easiest, or with a timing light at very low idle. TDC or 16BTDC (smog or non-smog) and lock it down, no need to move it again. Then deal with the fuel system. See if the jet tubes are moving down when the choke is pulled out and then back up when the choke is pushed in. Be sure the choke cables are seated in the little "cups" on the carbs and there is a little slack in the cables.
As Paul pointed out, have a fire extinguisher very nearby until you're sure it's running right.

[Linda]

Maybe a stuck carb piston? I had trouble with that one recently.

Linda

[jarhead]

Been there recently. My wife wouldn't get near me after working on it due to my gasoline stench in the clothing. Get the ignition done first THEN go to carbs. If you' re spewing gas on the ground from the overflow tubes, then its a sunk float or clogged carb intake valve from debris. But it's most likely not getting good or properly timed spark. Replace the rotor, cap, condenser(still not sure what that thing does....) and wires/plugs. Get it timed according to specs. good luck

[AidanDawn2000]

One of my SUs overflowed and it was because the little "U" shaped black fuel lines was clogged.

[mraitch]

are you sure the distributor is correctly installed?? wiring attached to correct plugs??

[Lorna c]

well I was so wrapped up in this mess I didn't know how to find these responses.. what ended up being wrong with it , well it was extremely rich ! the settings the mechanic did when he set them up was messed up when I asked my son to check the bolts for tightness and apparently he tightened up some of the carb things too not knowing . . lol so basically everything was all messed up . he finally told me about a day later ... hahah thank goodness I know more today then yesterday .. thanks for the responses .. once I posted I couldn't go back to read these . but reading these now has refreshed me and taught me some thing too . thanks