What a great write up! Can I ask a quick question on the float adjustment? It's meant to be 7mm closed 15 mm open on the 26. Do the same float measurements apply for the 28 as well? I can't find a 126 Haynes manual just now...
Morning Labman;
Check the carb as per all the advice on this subject (float, float level, needle-valve etc.) plus, check that the top cover of the carb is level and has not warped, although if your carb is leaking as bad as you say it is, too high a fuel level would be the most likely cause--definitely check the float.![]()
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The 26imb is very prone to the bottom flange and the top cover warping. The 28imb is a little more robust but can suffer similar problems. I use my large 5" jaw vice with suitable bits of packing to press the carb parts back into shape. The problems are generally caused by over tightening of the screws and mounting nuts.
The 26imb is very prone to the bottom flange and the top cover warping. The 28imb is a little more robust but can suffer similar problems. I use my large 5" jaw vice with suitable bits of packing to press the carb parts back into shape. The problems are generally caused by over tightening of the screws and mounting nuts.
The picture looks fairly typical of what I have come across on a number of the carbs. I had already straightened a few bottom mounting flanges by that time so I was pretty confident that there was a degree of flexibility in the metal alloy . I removed all the parts from the top cover then with parallel bars across the holes on the underside to give clearance for the float chamber pivot mount I applied pressure in my vice. Just like the bottom flange I found it impossible to get it totally straight with the amount of pressure I was happy to apply so I did a little more work holding the cover in my vice and giving it a few taps with a small mallet.
I also had this problem, but not quite as bad. I used a flat file to remove the high spots until it laid flat
Do NOT under any circumstances use gasket sealer--there is a real risk, due to the thinness of the bowl wall and the proximity to jets, that as you tighten down the top of the carb onto the main body that bits of sealer will be squeezed out and enter the jets and (fine) passages in the carb--then you really will have running problems!![]()
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First of all, find yourself a 2nd pair of hands (girlfriend, wife, sprogs etc) and a selection of small pieces of hard timber (soft woods tend to crush too easily). By putting pieces of timber on both sides of the top in places that will allow you to bend AGAINST the bow, you can VERY GENTLY straighten out the top--BUT BEWARE--it is made of what is colloquially known as '**** alloy',
it is not very strong. Proceed very carefully--you might still need to buy another carb, but at least you will have done all you can to retain the original.![]()
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