AOMCI Members Only Forum

[Sam M.]

Nevada wrote:

Please forgive it this is wrongly placed. I have a1963 Scott McCullough Elgin 7.5 hp. low profile. Ive rebuilt the Tillotson carb.replaced the lower unit, replaced the recoil spring and srarter assembly. I put new old stock impellers in it, upper and lower, and made sure they were in the correctly. But on the very first trip out on my flat back canoe it got to hot. Hot enough that it shut down on me. But it didnt lock up. It was like it ran out of fuel. But, no dought, it got to hot. Now there is no compilations on nether cylinder. Ive put alot of time in to it, not to mention the money. Can someone please tell me what did i do wrong? And what would be some ways to fix it so it dont happen again? Thanku,Hot on the water, Nevada.

There a few things that come to mind:

• Did you compare the shaft length of your motor to the transom height of your flat back canoe?  The anticavitation plate should be roughly in line with the bottom of your boat (or in this case, canoe).  If your transom is too tall for your outboard, your outboard may have trouble getting cooling water at higher speeds.
• Did you mix in enough oil in your fuel?  I don’t know the right mix ratio for your motor, but friction generates heat.  Motor oil dissipated heat and reduces friction.  Also, outboard oil with the TC-W3 certification is the stuff to use.
• Was your motor pumping water when you noticed it get hot?  If so, did it look like very much?

I have not worked on your exact motor before but assuming it has the conventional type of water tube and grommets, the following should apply:

If you aren’t sure enough water was circulating through the motor, I would reccomend you do some disassembly again and check the condition of your water tube grommets and impellers.  Specifically, check if the grommets have tears or if they are out of round and consequently wouldn’t properly fit on the water tube.  Also, check if any impeller blades have fallen off your N.O.S. impellers.  Unfortunately, older rubber can’t always do things that it was able to do when fresh, such as tolerate lots of bending without cracking.  If you find a damaged impeller, then instead of replacing it with another N.O.S. one, look for an impeller of very similar size that belongs to a different brand of more recently produced outboard.  Some collectors have found an impeller for Honda motors that works for certain Scott-Atwater motors and McCullough bought Scott-Atwater so that might give you a start.  When reinstalling the parts, put some oil in the grommets so they don’t tear when inserting the water tube.

I would also reccomend you double check your canoe’s maximum hp rating as canoes are often rated for 3hp or 5hp and overpowering can damage your vessel.

Finally, to start a thread, either read Aidan’s comment above (4th comment in this thread) and follow his instructions or find the Members Only drop down somewhere at the top of your screen (probably top right but I think it varies for different computers and devices) and go to the Active Member Forums, click on the most relevant one to what you want to post, scroll the the bottom, and create your thread there.

[Author]

Posts