Inlet manifold T3

Just tried to get the inlet manifold of my T3 carb. Is it glued on? I’ve loosened the clamp and its absolutely solid. What’s the technique apart from hitting with it a large hammer and then an even bigger one?
When re-fitting the carb / inlet manifold assembly should I grease the (new) gasket? The old one looks pretty dry.
Help appreciated!

The carb should just pull off the manifold, then undo the 3 allen bolts and the manifold should pull out. From memory, it has a stub going into the head, although it is a very long time since I removed mine A gentle tap with a rawhide mallet should suffice to loosen them off.Don-Spada2014-05-08 20:17:09

Should separate once the 3 allen bolts are removed, if not a tap with the hide hammer. I use grease on surfaces when replacing.

I think he means the carb connection onto the inlet stub. I think what happens is over time the clamp squashes the carb sleeve (?) andmakes it too tight. There’s a plastic sleeve inside. There should be slots in the carb casting, may be possible to insert small screwdriver blade and spread them a bit? Not tried this. So far I’m normally able to twist the carb off the stub.


Just done mine, had to persuade them off with a few hammer taps with a piece of wood to prevent damage. I put a smear of grease on the new sleeves when I put together.

Thanks guys. I managed to get the manifold off by taking the carb / manifold assembly off, taking off the cables and the pipe extension between the carb and the air box, reattaching the manifold & carb and then gently tapping the carb back away from the manifold. The manifold on the right side has disintegrated around the screw holes and I fitted a replacement. I asked my friendly polishers to give it a bit of buff and you could now use it as a shaving mirror.

There are two pretty heavy duty gaskets, one thick card and the one closest to the engine looks like asbestos. They are in good shape. When I re-use them is it recommended to grease the surfaces on re-assembly?

Aaaah of course, you still have the original air filter assembly fitted. That is why it was so difficult to get it apart. Most bikes by now have had this discarded and K & N type filters attached. Removing the carbs then becomes a 2 minute job. I wonder what has attacked your right hand manifold. They are a chunk of aluminium and not normally known for disintegrating.A smear of grease can’t do any harm, it will help next time you want to take it apart.

Note these two thick gaskets must be used, else the bolts will just bottom out in the head and the joint won’t close up. In other words, if it won’t close up, it’s trying to tell you summink’s wrong.

I’m not sure what was the matter with right hand manifold. Perhaps a spot of metal fatigue like the old Comet airliners. The metal was just crumbling away from the screw holes like a disintegrating hobnob. Anyway, I managed to get two perfect manifolds from a chap in Germany. When I rebuilt old Rover P6s years ago I used to smear all the paper gaskets with grease to get a good seal. I’ll do the same with these manifold gaskets unless somebody tell me different. They look like they have been assembled “dry”. I have read about the frequent need to use two gaskets on each manifold but is one paper and one asbestos? bigsunburst2014-05-10 17:39:16

Not heard of that, all the ones I’ve seen in gasket kits etc. are the same type, doubled up. Guzzi gaskets can normally be assembled dry. Also removed and replaced several times. Obviously not apply if gasket goo involved, as gasket is destroyed taking it apart again. Crumbling screw holes ~ this reminds me that these holes have temperature insulating sleeve inserts, actually, so not all metal no. For this reason screws should have plain washers under the heads, to prevent possibly damaging this insulator.