Flooding Recon Carb (Stromberg 150)

[AndyWorms]

Hi,
I recently purchased a Vit MKII 1969 and noticed the front Stromberg 150 was flooding.
I decided to get a couple of recon stromberg 150s from Canleys which i did and fitted a few days ago.
Everything seemed fine apart from a slight weap of petrol from the choke housing when choke was on.
I had the carbs balanced by a mobile tuner and everything seemed to be running fine.

Took the car out today for a quick run and a couple of miles from home the car started to splutter and cough.Pulled over lifted the bonnet and found the recon front carb flooding petrol.

Any ideas anyone ? Am i just unlucky and have a faulty recon carb and its just a coincidence that i had this problem on the previous old unit or could something else perhaps the fuel pump be to blame.
I have a in line fuel filter and the fuel does seem clear.

Not sure what route to take now.
Any advice will be welcome.

Many Thanks

Andy

[Nick Jones]

Andy,

This is a favourite Stromberg trick and almost certainly caused by dirt behind the needle valve - it doesn't take much.

You'll have to drop the float chamber off to dismantle and clear the valve unfortunately and while you are at it, just check that the float isn't full of petrol.

One further possibility is that if you have a new fuel pump, some of those currently on the market generate too much pressure and tend to force the needle valves open.  Choices to rectify that are to find a serviceable old one or fit a pressure regulator.

Hope this helps

Nick

Edit:

I notice you seem to be in the Exeter area - we occasionally organise a meet in Honiton, keep an eye on the Area News on this message board for the next one - no regular date set up yet.

[AndyWorms]

Hi Nick,

Thanks for info.
Seems fixed for now after bending up float tab a small amount to close valve earlier.
Will need to monitor it because after i fitted the recon carbs last Thurs it was running
fine and took the car on a test drive for about 30 miles with no probs.
Then this morning went out for a short trip and after about 5 miles the carb started to flood which makes me a bit concerned about the  fuel pump pressure as a possible fault.
Will also keep a check on the Area News for local meet.

Regards

Andy

[AndyWorms]

My old problem returned yesterday.Fired car up ready for a quick spin when the smell of petrol returned . This time it was the rear carb flooding. bent the tab up a little and once again seemed to run fine with no leaks.

I have had some advice to replace the Float valves with Viton rubbertip ones does anyone know where these can be sourced ?
Im also going to get another fuel pump to try and eliminate that as a cause of all these flooding carbs.

Dont know what else to do unless i send these Recon carbs back under warrenty.

Regards
Andy

[Deleted User]

Andy,
the bending of the tab to set float height is part of the setting up procedure, and as such wouldn't be covered under warranty.
It might seem like a big deal, but it really is just normal for stombs.

As for the fuel pump, if it is standard cam action type, and it isn't leaking, or under pumping then its fine!

[Richard B]

Have you got an in-line fuel filter? If the tank is rusty (internally) or you bought some 'crap' petrol then you could have problem which is neither the pump nor carburettors fault.

Alternatively I have had a problem with the pump developing too much pressure, but as yours is more of an intermittant problem I would suspect dirt in the system.

[AndyWorms]

Yes i have two inline filters one tank end and one carb end. Replaced both just in case and bleed fuel through to clear any muck.
Still trying to find some info on these viton rubbertiped float valves if anybody has hard of them or knows where to get them ?. I have a feeling these recon carbs have cheapo valves in them which could be my troubles.

Andy

[Clive]

speak to canleys, if there is a problem they will sort it, and will be honest about the quality of the parts. However, it really does sound like dirt in the system, mabe the fuel pipe, rubber braking up slightly or something? Have a look at the valves and check them. There is little to go wrong with them as long as the seats are ok, and the flots set correctly.

Clive

[Deleted User]

I've just encountered the same problem on mine (no in line filters  :o).

Is it worth overhauling the carbs with a service/repair kit at the same time as taking them off to clean? How can I tell if this needs doing?

I'm pretty sure I can do this even with my limit skills, but setting them up could be a different matter  :-/

[Hasbeen]

I have had this problem with a number of Triumphs, with both SU, & ZS carbs.
To start with, I don't believe the needle & seats are as well machined as they were, so it takes less presure than in the past to make them flood.

But I think the main problem is with replacememt pumps workimg at higher presure, than our old ones did, & pressure regulators appear to be more trouble than they are worth.

Fortunately, this is easily corrected.
The pumps do their pumping with their spring. The cam is used, only to compress the spring.
This spring is spirally wound, giving a variable spring rate. Therefore, a small change in the compression of the spring, has a quite large effect on the output pressure.

I have found it only takes about a 1/16" to 3/32" spacer between the pump, & the engine block to drop the pressure by about one PSI. This should be enough to stop the flooding.
Take the thing for a hard run when done, to make sure you have enough supply, & have not introduced fuel starvation, at sustained high revs.

On my 7, with Dolly Sprint SUs, I found 4 thicknesses of Corn Flakes pack was just right. Mind you, this was top quality Corn Flakes, not those cheap ones.