65 hp merc. ?

[87hydro]

I have a 1966 65 hp merc.4 cyl. that I'm going to put on my 12ft. Hydrostream Hustler. Did Merc. offer a shortshaft version of this model? This lower unit measures 25". I need 20" or less. Thanx-
87Hydro:""

[Raceman]

It was available in a shortshaft also. Not only that, but there were many engines from the 60's and early 70's that the mid section would interchange from. Basically, the gearshift 4's and 6's from the early 60's up through all the 71's, plus the 72 4's and the 72 115 HP 6. The 72 1400 had the newer bolt pattern as did all the 73 and newer engines and won't work.

The problem is, the old 4 cyl crossflows aren't big performers and don't respond well to modification. You'd probably be better off to find a newer 3 cyl Merc or 3 cyl OMC looper.

[87hydro]

Thanks for the info. The Hustler only weighs 300 lbs. and is the tunnel version. I figured this might be enough motor to see 50 mph or so. Thanx 87Hydro:""

[Raceman]

If you can't find one, let me know and I'll look around with some of the AOMCI guys. There should be tons of those laying around. You might even try an ad on the AOMCI website:

WWW.AOMCI.org (I think)

[10.5' Tunnel]

Raceman, any cheap mods i can do to my 3 cyl 65 hp merc?

[87hydro]

TX for the info. Hope to have it ready for the Rumble. 87Hydro:""

[Raceman]

Not that I'm aware of 10.5. Most of the inline direct charge motors don't respond well to modification, especially port timing changes since there's no way to raise the compression.

[10.5' Tunnel]

Thanks I was just wondering:)

[Dave S]

You can get rid of the exhaust tube on both style small Mercs. I will post some pictures. I also have 15 inch housings for older Mercs. I have old Merc parts if you need. Please answer in the private message or on this Board. Thanks. :D

[Dave S]

My picture's in the next Board. I messed up.:rolleyes:

[Dave S]

She looks worried.

[10.5' Tunnel]

Thanks dave, ill keep you in mind if i ever need parts for my merc. I have wondered also about releiving the exhaust, but would need some way of plugging the holes. Post some pics if you can;)

[Raceman]

10.5, relieving the exhaust on an inline type mid can cause strength issues, but I doubt you'd encounter them with a 4 cyl since the housings are strong enough to support the stresses of an inline 6. The thing is, it ain't gonna help anything but make it sound cooler. That system's got plenty of capacity to dump the exhaust of that powerhead without restriction.

[Mark75H]

Be careful with the 65. Merc made the propshaft shorter on them so you could not accidently overload them with props for the 6's (which have the same splines, etc). So, if you find a short set up from a bigger motor your original 65 props will need a spacer added to fit correctly on the longer prop shaft. This also reduced the possibility of over revving a 6 with a prop made for a 65.

Poor Daisy. Please let her out of the boat, you have to be 18 years old to drive Formula E, she's not that old.

[Raceman]

Sam, I never knew that about the propshafts. I thought they were the same. I'd go measure the two old 4 cyl 650's I've got, but there's no way for me to know if the gearcases are original after all these years.

[OLEGATOR]

IF I'M NOT MISTAKEN, THE EARLY SHAFT DID NOT HAVE THE TAPER AND USED A DIFFERENT THRUST WASHER. MY MEMORY HAD A BIRTHDAY A WEEK OR SO AGO, SO I COULD BE WRONG ABOUT THIS. IF I'M WRONG AT LEAST I HAVE AN EXCUSE.

[mercmack]

OLEGATOR...THE BIRTHDAY HASN'T AFFFECT YOU TO MUCH, IT IS TRUE THAT THE EARLY 650 DID HAVE A NO-TAPERED SHAFT PLUS THEY WHERENT THE BEST QUAITY STEEL ETHER, RIGHT WHERE THE TWO SEAL RIDE ARE PRETTY GROVED UP AND PITTED BY NOW . A GOOD OLD PRESSURE CHECK WON'T HURT.....THEY HAD ALL METAL WATER PUMP HOUSINGS AND DRIVES ARE SH**** sSO THE SEALS AND RUST HAVE DESTROYED THE SHAFT IN THAT AREA .:rolleyes: :rolleyes: :rolleyes: :rolleyes:

[Dave S]

They used that prop shaft in early 100 and 110 mercs. They switched to the tapper shaft when the 125 came out this is my info not 100 % to the bank. Best to get a newer style with ss drive shaft. You can raise the compression on the old L6 but it is lots of work.