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MG Midget and Sprite Technical - I messed my carbs up(pt II)

I had trouble with my carbs, and after a trip to the garage, they were back in tune and the car ran sweetly, however it brokedown on the trip home,my own fault, it ran out of gas...net result is that although I put new gas in, the car is back running rough as if the carbs are once again out of tune. I looked at the flow chambers and they had rust particles in the bottom, so I cleaned this out, along with the inline filter(which had a lot of crap/rust in it), needless to say the car refused to start, so I primed the carbs with fresh petrol, and off she went, but as soon as the fuel came through from the tank, it ran rough again.

The question is, is it time to replace the tank ? I think the rust/crap is coming into the fuel system from there, despite it never being much of an issue before ?

Or is the issue still with the carbs ?



RUS(59SPRITE)

Where is the inline filter (that you already replaced, right?) located? Are you still running the mechanical fuel pump? Ideally, you would probably want an inline filter just before the fuel pump and another one just before the carbs. Expect to replace them a couple times before you finish sorting this. It is quite possible that there is grunge in the inlet needle as well as in the jet itself. If you are still running the original H1 carbs, you will want to remove the floatbowl from the carb body and clean that connection as well.
David "should be shutting down the computers and going out to tweak my carbs..." Lieb
David Lieb

David,

the filter is inline just before the mechanical fuel pump, there isn't another before the carbs,so will investigate this,its acrying shame, as I was going to drive to Linsday,Ontario for the 'Brits in the park' event....looks like I am going in the VW Jetta.

Russell"really annoyed with anything old and britsh"
RUS(59SPRITE)

Russ,

My personal opinion is keeping the carbs as clean as possiable is 70% of a good running car, I always use 2 filters(one big then the 2nd small) right before the carbs and one before the pump and the tank...granted your a bit differant set-up...but still the same....I also use clear filters so I can see whats inside.....


So it looks like you only need 2 more filters as you replaced the one filter you tryed to clean out with a new filter... As david was enferring that you had done...is that correct???


prop
Prop

Also...I keep my fuel tank filled 3/4 filled as it IMHO keeps the tank from rusting . ...cause the steel tank walls are exposed to fuel not open air oxygen....as well as letting any junk to get sucked into the carbs like it would do if your running on 1/2 gal. of fuel. if the tank need cleaned or replaced....there cheap on ebay...so I dont know that I d waste the time to clean and seal it....thats what I did...no regrets

prop
Prop

Russell. No need to be annoyed with anything old and British. The fuel tanks on most old cars were made of sheet metal and will, over a period of years, rust out.

Replace the current tank because you do not know the extent of the rust present. Not worth investing time and money in a tank of unknown condition.

While you have the new tank off the car, take the time to give it a good coat of paint to protect the exterior. Some recommend "sloshing" the interior to seal it from rust. Have not tried this myself because I live in the desert. But, in an area with high humidity, water will condense inside the tank, particularly with lower levels of fuel. That is why we used to add some "gas line dryer" each winter back when I lived in snow country. But, your decision as to how you want to protect your new tank.

With the new tank, install a fuel filter just before the carbs--one that allows you to see any crud build up and remove and replace the filter easily. That will catch any residual debris left in the fuel lines.

What you are seeing is a normal part of restoring an old car to competent driving condition. It happens with all old cars, not just old Brit ones. Something that is a part of the learning process that driving classic cars is all about. Not a big problem.

Les
Les Bengtson

Prop,
You fill your tank after driving just a quarter tank worth of gas out? And I was complaining about having to stop every 200 miles or so to re-fuel! Must make any kind of a road trip into a tour of petrol stations...
David "Wish my tank was bigger" Lieb
David Lieb

LOL, yes David I do....but also other advantages...

Cause I only get to drive on occasion....not everday....the car sits....so its to prevent rust....BUT and a BIG BUT....I only use premium gas currently almost 5 dollars a gallon....by re-filling it after Im done driving it for a couple weeks to a month....It seems Im saving money....in the end Im sure thats not the case...put it feels like it, as I rarly put in more then 8 dollars, compared to the 26 dollars I put in at the lake for spidget 50 after letting it run dry.

Besides on a great driving day I hate stopping 1st to get gas and be reminded of how expensive gas is and how shafted Im getting at the pump from george's gay friends, and the real terrorist we have to fear "the Sudia Ariabiaians" the biggist benefactors OF and most protected terrorist responsiable for 911) ...rather do that "AFTER" I have had a great day of driving fun.

prop
Prop

reading a little further into your reponse...I only re-fill at the end of my driving session but I do perfer to re-fill at the below 1/4 tank level if on a longer trip where I need to re-fill....but that rarely happens...

sorry for any confusion
prop
Prop

You? Confusing??? Perish the thought!
David "I can usually figure it out eventually ;-)" Lieb
David Lieb

well, I put another filter in the line, just before the carbs, but its still running rough and down on power, I think the carbs are in need of a strip down, don't have time for that as the show is today, thanks for the input anyway...
RUS(59SPRITE)

try spraying so wd40 over the carbs and intake manifold while the engine is idealing and at proper temp....if you see a pick-up in idel....you will have a leak in that area where you are spraying....if this is the case make the nessary tightening and adjustments.....Also check that your dash pot oil on the carbs is at the proper levels and is 20/50w motor oil

If that dosnt get it....check that those tubes going from the bowl to the carb bodys are clean...NOT visaully, test by feel...with a paperclip , pipe cleaner..heavy gauge solid wire....resistance means blockage...eyesight is ill-relevant
get some pipe cleaners....kids hobby, craft, school supply store and worm them thur the 2 little platic/rubber tube that connects the fuel bowl to the carb.....this is the jet assembly....also use some brake parts cleaner in spray can with the tiny little spray straw, that can all so worm its way thur there.... if there is blockage and the spray cleaner wont break is up, clean out the excess liquid junk and fill the bowl partially with penatrating oil and let sit over night and then apply previous cleaning methads to break out the blockage, the bottom line make sure those tubes are not cloged, and whistsle clean....you may have to remove the jet assembly...if so make notes and get a haynes manual to tell you how to reset everything...let us know of any problems you have and we will walk you thur it'''


prop


Prop

Put a can of SeaFoam in the gas and run it. Wonderful stuff, even if carbs are too dirty for this to work this time, stuff is good preventative maintenance.
J Van Dyke

This thread was discussed between 12/07/2008 and 13/07/2008

MG Midget and Sprite Technical index

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