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Strombergs Flooding and won't start

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Hegg

Hegg

Jedi Hopeful
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Heh, I just read the post by sammyb that his carbs won't deliver fuel after a rebuild. Well, mine are flooding!

I had the problem before and after a carb rebuild. I crank the engine and it doesn't even try to start (usually). Plugs are soaking wet and lifting the air valve on the Stromberg 175 CDs shows a little puddle of fuel down by the throttle plate.

Where do I start? Could I be getting too much pressure from the fuel pump? I replaced the needle valve with the one from the kit. I double checked the float level and it was exactly where it needed to be. The needle spring seems to be biased to the side just fine. It's just wet with fuel all over in there.

Both carbs are having the same problem. I don't really understand how the needle seat and the jet seat are supposed to sit... should they be absolutely flush with the surrounding body? Both carbs are inset by a millimeter or two on both the needle and the jet.

Thanks everyone!
 
If these were SUs, I'd say the float level is off -- adjust the floats down a smidge.

Tell you what -- I'll exchange half of your "too much fuel" for half of my "not enough fuel" and we'll both be back on the road!
 
[ QUOTE ]
Tell you what -- I'll exchange half of your "too much fuel" for half of my "not enough fuel" and we'll both be back on the road!

[/ QUOTE ]

Deal! What's your address and I'll send you 1 flooding carb. /ubbthreads/images/graemlins/cool.gif

I've taken a couple shots of the needle seat (the best I could). This is the way both are seated, so I just assumed it was right. But if that's the case, what's keeping the jet "closed"? (click on the pic for a beeeeeeg version)

 
Wow, you have me confused. From your first post I thought that you were talking about the float bowl needle & seat which "could" be the cause of flooding. Your pics show the metering needle & seat which would have very little, if anything, to do with flooding. Check out the float bowl inlet needle & seat for flooding problems. It is where the fuel from the fuel line first enters the carb.
See if this helps; https://www.geocities.com/britishiron2000/carbs
D
 
Exactly what I went through in the summer. If your car has a mechanical fuel pump, like my TR7, then my problem was the electronic ignition was shot. The fuel would just keep getting delivered, but no spark to burn it. I took mine apart and rebuilt too, before this was figured out.
I couldn't figure out why the gas was just sitting in the intake either.
Worth a shot.

Paul
 
-Check that the needle valve is seating properly.
-Check that you adjusted the float height correctly.
-And check that your float isn't filling with gas.
 
Yeah, yeah, sorry about the confusion. It was a little too late for me to try to be describing something. /ubbthreads/images/graemlins/smile.gif

I guess what I'm trying to ask with that is when the air valve is fully down, and if there's a gap on both the top section (metering needle) and bottom section (jet), it just seems like that's a pretty big "hole" for the leanest mixture possible. I dunno... I'm just thinking out loud (and I'm also more familiar with working on a Ford carburetor with weird things like idle mixture screws /ubbthreads/images/graemlins/cool.gif).

Thanks for the link, and thanks to the others for suggestions. During the rebuild, I checked the new needle valves and they seemeed fine. I double-checked the float level and it was spot-on. I shook the floats and they didn't sound full of gas.

I'll take 'em back off and see what I can find. Thanks again!
 
[ QUOTE ]
I don't really understand how the needle seat and the jet seat are supposed to sit... should they be absolutely flush with the surrounding body?

[/ QUOTE ]
Steven--The fixed jet should be recessed a few mm below the carb bridge (your pic shows this to be the case). As an initial setting, you should set the needle so it's brass base is flush with the bottom of the air valve. That should leave you with 2 to 3 full turns CW for a richer mixture (if needed) when you balance/trim the carbs. As others have said, double-check your float heights (17 mm ??) and make sure you put the correct washer under each needle valve. Also, make sure your 'starter boxes' (chokes) are functioning properly.
 
The float level was 16.5mm WITH the metal washer underneath the needle valve. Should I take the carbs off and maybe change it to 18 or 19mm?

Also, only one carb has a 'starter box' on it -- the other one is just sealed off with a gasket. But both carbs are being flooded, so it must just be an adjustment I did wrong. I'll take 'em off and bump the float down a few millimeters.

Or should I try to adjust the mixture? Since Rick O. mentioned that the seat of the mixture needle should be flush -- in the pic it's about 1 mm inset.

Thanks!
 
[ QUOTE ]
...I had the problem before and after a carb rebuild. I crank the engine and it doesn't even try to start (usually). Plugs are soaking wet...

[/ QUOTE ]

Perhaps the problem isn't the carb at all. Have you confirmed that ignition is occuring correctly? Will it start with starter fluid?

I can't tell how many times my 'carb problem' was fixed by working on the ignition.
 
The engine *has* started once (before the carb rebuild), so I'm reasonably confident that ignition works and all that, but it would be worth doing further investigation on. Thanks for the tips!
 
i've found on my ZS's the float height given in the manual is only a ball park figure and I had to adjust slightly less float height to work properly. my problem was that I was getting fuel flowing out the anti-run on valve. quite noticeable after stopping.
 
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