Traction running rich

Thanks Gerry, I'll put the carby back and try that. At your suggestion, I very carefully wiggled the emulsion tube out (I can understand why you said to not turn it with a screwdriver in the top - there's a little lug at the bottom which sits in a groove and this could be damaged or broken, as you said.) It took a while to get it out as it was pretty tight so I don't think there would be any leakage there. Anyway, I'll Loctite it back and try your pump suggestion. Thanks again for your helpful hints.
Rod
 
Rod the emulsion tube is in the spray tower and is accessed by unscrewing the air correction jet that sits on top of the spray tower assembly. DO NOT loctite the emulsion tube inside the spray tower. Only loctite the brass tube at the base of the spray tower assembly. This is where fuel is fed after it is metered by the main 135 jet. The fuel float level governs how high up the spray tower fuel will sit at rest. Venturi action draws the fuel out of the spray tower at the side ports and forms a mist to feed the engine.
 
GERRY, Whoops,I think I referred to the spray tower as the emulsion tube. Yes, I'll only Loctite the base of the spray tower. Thanks for the warning.
Cheers,
Rod
To check the needle valve cut off hand prime the fuel pump until it cuts out. If it does not then look at the drain tube from the manifold. If fuel runs freely here then the float chamber is flooding. BTW when the float guides in the float chamber become extremely worn the float can stick and fail to close the needle valve. I suffered this problem once but it would only occur intermittently.
Hi Gerry,
You mentioned the drain tube from the manifold; what drain tube? I don't think I have one!
Cheers,
Rod
 
There should be a drain tube below the carburetor on the inlet manifold. It sits above the exhaust hot spot and mounts with a 12mm headed hollow screw fixing. It is shaped roughly like a question mark.?. It has a tapered outlet with a hole that is calibrated to minimise air leaking into the induction whilst running. Its purpose is to clear excess fuel from the manifold in a flooding situation.
The link shows a reproduction unit. It is not properly tapered nor is it properly shaped.
 
Hi All, Just an update on my Traction running rich problem, about which many of you posted helpful hints. I've tried all those solutions and it still runs rich. So after speaking to a couple of friends, (one is a retired French car mechanic), I have decided to follow their advice to get the car out on the road, give it its first good run after a totally recond. engine, blow out a few cobwebs, put it under load and see what happens. This won't be for a while as I'm waiting on the concrete to be poured for the drive (lockdown prevents this at the moment) so that I can get the car out of the new garage. Thanks again for all the help, will let you know what happens. Cheers, Rod
 
Flooding [running rich] can be caused through few things that need to be eliminated ~ also if one has done anything related to the fuel system that can introduce a problem.
1. fuel pressure too high ~ mechanical fuel pump related ~ needle & seat not sealing when original manufacturers pressure is reached ~ spring under fuel pump diaphragm governs fuel pressure ~ too strong will cause over pressure & flooding ~ Solex is especially prone to over pressure flooding.
2. dirty needle & seat [plastic inline banjo filter broken up] often evident in vehicles not used regularly causes not sealing & flooding.
3. crappy old fuel, especially ethanol stuff causes all kinds of fuel issues.
4. too high float level can be a flooding issue ~ most every carburettor float level can be set by turning the top plate upside down & the float should be parallel with the turned over top.
5. choke [Solex cold start] not being fully off when temp is reached or a problem with the cold start setup.
 
Hi Everyone,
Have a problem with my L15. Starts and runs beautifully but after about 10 minutes starts to run rough. Pull out the plugs and they are all sooted up. Exhaust is also black. Clean the plugs, put them back, starts well and runs for a few mins then same thing happens. I've cleaned all carby jets, increased the thickness of the washer under the float valve, adjusted the mixture screw, all to no avail. It has a 123 ignition fitted. Got me bamboozled! Help! Thanks, Rod Smith
Hi Carpetsnake.
I just want to clarify the operating conditions. When you say "...starts and runs beautifully..." I assume the vehicle is stationery for the 10 minutes it takes to run rough?

Is the engine idling during this time, or are you holding low revs or medium revs, or are you cycling the engine from idle by blipping the throttle then allowing the engine to return to idle. All of the afore mentioned conditions bring into play different fuel circuits within the carburettor.
 
Flooding [running rich] can be caused through few things that need to be eliminated ~ also if one has done anything related to the fuel system that can introduce a problem.
1. fuel pressure too high ~ mechanical fuel pump related ~ needle & seat not sealing when original manufacturers pressure is reached ~ spring under fuel pump diaphragm governs fuel pressure ~ too strong will cause over pressure & flooding ~ Solex is especially prone to over pressure flooding.
2. dirty needle & seat [plastic inline banjo filter broken up] often evident in vehicles not used regularly causes not sealing & flooding.
3. crappy old fuel, especially ethanol stuff causes all kinds of fuel issues.
4. too high float level can be a flooding issue ~ most every carburettor float level can be set by turning the top plate upside down & the float should be parallel with the turned over top.
5. choke [Solex cold start] not being fully off when temp is reached or a problem with the cold start setup.
Thanks Ringer, Checked most of those things. Hopefully when it's on the road I'll be able to sort things out. Cheers.
 
Hi Carpetsnake.
I just want to clarify the operating conditions. When you say "...starts and runs beautifully..." I assume the vehicle is stationery for the 10 minutes it takes to run rough?

Is the engine idling during this time, or are you holding low revs or medium revs, or are you cycling the engine from idle by blipping the throttle then allowing the engine to return to idle. All of the afore mentioned conditions bring into play different fuel circuits within the carburettor.
Hi Whippet, yes, car is stationary while idling but I sometimes rev it up for a few seconds- medium to high revs, then let it drop back to idle. Cheers
 
Hi :)
I would just add that any obstruction in the air filter will cause a choking effect and enrichen the mixture. If you are putting the filter back on you should check for unexpected obstructions inside it possibly ?
Jaahn
 
Also to add:
Overfilled or heavy grade oils being used in oil bath filters do the same thing as Jaahn just mentioned.
 
Hi Whippet, yes, car is stationary while idling but I sometimes rev it up for a few seconds- medium to high revs, then let it drop back to idle. Cheers
Hi.

Also you mention "The engine has been fully recoed last year..." Self evidently the engine needs to be disassembled and reassembled to achieve this. Are you confident that the valve timing is correct, and also the ignition timing is correct.

I note that the vehicle has 123 ignition fitted, I assume that various looms have been disconnected and reconnected as part of engine overhaul. Have you actually checked for a decent spark at the end of the ignition lead on each spark plug in turn while engine is idling? Withdraw the high tension lead from spark plug in turn and check for a big fat spark from end of high tension lead to engine block, with a gap of up to 6mm.
 
Also to add:
Overfilled or heavy grade oils being used in oil bath filters do the same thing as Jaahn just mentioned.
Hi :rolleyes:
Just a thought on what might be found in old vehicles. My mate bought a farm and I went up to help him service things and get the gear going so he could get to work. It had an old MF tractor that started and ran OK at a quick run and was last as it was going. But when we looked at the oil bath air filter to drain it and wash the gauze and bowl it was too hard so we removed it completely so we could do it properly. The bowl had cement like black sediment to the line. The gauze resisted all efforts to clean the straw and crap out and in the end it took an hour with a pressure washer to get it all to a working state. Hmm not serviced often over the years I guess !!!! Strangely it did not seem to make much difference to the way it went after. Just an old slugger I guess. :)A petrol engine would not like that for sure ! ;)
Jaahn
 
Hi :)
I would just add that any obstruction in the air filter will cause a choking effect and enrichen the mixture. If you are putting the filter back on you should check for unexpected obstructions inside it possibly ?
Jaahn
Hi Jaahn,
car doesn't have an oil bath, just the normal air filter, which is new and I've run the engine without the air filter - no difference.
 
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Hi.

Also you mention "The engine has been fully recoed last year..." Self evidently the engine needs to be disassembled and reassembled to achieve this. Are you confident that the valve timing is correct, and also the ignition timing is correct.

I note that the vehicle has 123 ignition fitted, I assume that various looms have been disconnected and reconnected as part of engine overhaul. Have you actually checked for a decent spark at the end of the ignition lead on each spark plug in turn while engine is idling? Withdraw the high tension lead from spark plug in turn and check for a big fat spark from end of high tension lead to engine block, with a gap of up to 6mm.
Hi Whippet, yes, timings are correct as of last year. They were set by an experienced engine rebuilder. If they were not correct, wouldn't the engine be difficult to start and not run smoothly? Checked for spark with one plug but I'll check all the others tomorrow.
 
Jaahn didn't mention oil bath, I did - & the reason I did was not necessarily related to your issue but in the interest of others perhaps learning something they were unaware of.
 
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