1964 Mcculloch/Scott Sears 7.5hp troubles, HELP!

[wulfgar]

I have the 1964 sear mcculloch 7.5 motor. It will start and run, but only if the choke plate is roughly 2/3 closed. If I open up the choke, it dies. I have replaced the fuel inlet fittings, hose and primer bulb, cleaned and set the points ignition, cleaned the carburetor and replaced the plugs. If anyone has any good ideas, I would be indebted for them. thanks.

P.S. If anyone has a manual of some type for this thing that they can send me PDF or any other way, I wouyld be very grateful.

 

[steelespike]

Re: 1964 Mcculloch/Scott Sears 7.5hp troubles, HELP!

You should be able to find a generic manual on ebay.You might find one at the library.
Is it a Tillotson carb or Marvel Schebler?You adjust the Schebler float by sliding the float pin till
the distance between float and meter body is between 1/8 and 9/64 of an inch with the needle valve closed.Have you tried squeezing the primer bulb to keep it running?

 

[jaybow]

Re: 1964 Mcculloch/Scott Sears 7.5hp troubles, HELP!

I have two of these scott- mccullough motors left out of three. TWO HAVE MARVEL-SCHEBLERS and they run , after replcing diaphram in one. It has seperate fuel pump just aft of tiller handle. Got dia. from DORA at www.americanoutboard.com. Other one is Tillotson carbed with two internal diaphrams, stillwaiting... If you try dora be patient. Hope this helps.

 

[jaybow]

Re: 1964 Mcculloch/Scott Sears 7.5hp troubles, HELP!

Re:1964 Mc/Scott 7.5 I have two of three 7.5's left. 1Ted williams ran right away,one 1962 that had a fuel pump for a remote fuel tank. The diaphram had to be replaced. That pump is located just aft of the tiller on left side of motor. Two I have made run have Marvel-Shebler carbs. Ifyours is a Tillotson it has two internal diaphrams one or both may be bad. I can recomend a source, but am not sure if proper on this site? Someone please advise.

snuffbucket.