Question on Replacing Exhaust Manifold

Thu Dec 02, 2004 7:31 am

I am going to replace the manifold on My Cub this weekend. It wil be major surgery for my limited experience.

The clearance for the bolts behind the tubes looks very close. What should I use a box end wrench or a socket? :?:

Should I get a new gastket, too? :?:

The PO used a piece of radiator hose for rubber connector between the carb and the intake tube. Should I replace it while I am into it? :?:

Anything tips that you have for me before I start, I greatly appreciate. :D

Thu Dec 02, 2004 7:42 am


I'm not as experienced as the others, but I would suggest that you use a new manifold gasket - cheap insurance against doing the job over again if it leaks. If the radiator hose piece between the breather and carb is in good shape, there may be no need to change it. If, however, you're looking to get closer to original, OEM sells 1-ply rubber connectors and old style clamps that look sharp.

Thu Dec 02, 2004 8:17 am

As far as wrenches used I had to use a box/end wrench for the center nuts. If you clean the threads good first it will be easier. The studs are fine thread but if clean they will turn off with fingers after busted loose. Use WD or PB to help. And definatly use "NEW" gaskets.

Thu Dec 02, 2004 8:40 am

Run a tap over the end if you can and do that again after every thing is apart. Use never seize on the threads when you re assemble. It was not uncommon to break off studs working on the exhaust of old cars and old tractors should be the same. If a nut starts to lossen and then binds, tighten it wd40, clean the threads again, more wd40 and then lossen again. If you need to do it a number of times, just do it. A lot of extra time and care will prevent the need to drill out broken studs.


Thu Dec 02, 2004 9:55 am

The original hose on the carb was not 1 ply radiator hose. Radiator hose does not stand up well to the occasional shots of gasoline it gets when the engine floods. The original was considerably heavier, 3 ply.

If the current hose is pretty solid, I would probably reuse it. When I needed to replace one, I went to an industrial rubber supply house and bought a foot of gas pump hose. Some pumps use 1 1/4 inch hose. That stuff has a layer of metal in it! With all the vapor recovery systems, plain gas hose may be getting hard to find by now.