Putting a starter on a Mac

Friendly

Platinum Member
Joined
Jan 5, 2004
Messages
4,441
Location
Woodworth, LA.
Aircraft
KB2 & KB4
Total Flight Time
110
The flywheel is an old OMC or Johnson outboard . I think you could order a flywheel from Tom Milton and it would move the ring gear closer to the prop. also much lighter than the heavy cast alum piece.
Ford starters for a 2000 4.5 engine will fit Toms flywheel, I think. I will have to look it up. This is a 9 tooth pinion starter and Toms flywheel will match. Here are some general measurments to help you get started. An old Mac cylinder gasket will help get your brackets drilled correctly since it bolts to the two most rearward cylinder bolts on each side.
 

Attachments

Minnesota_Mike

Active Member
Joined
Oct 5, 2008
Messages
1,151
Location
Panama City, Panama
I've got 4) 72's...two are intact and two are parts.
I plan on tweaking at least 2 to be used someday.
Rounding up parts, gaskets...and of course CASH for the tasks involved.
The machine I'm building right now is a Bensen style 8" drop keel with a 100Hp Subaru EA-82 & redrive/ 68" Warp Drive.

M-M
 

Friendly

Platinum Member
Joined
Jan 5, 2004
Messages
4,441
Location
Woodworth, LA.
Aircraft
KB2 & KB4
Total Flight Time
110
You are welcome for the drawings.
Dave had to make some modifications to the plate for Marion's prerotor. And he changed the starter as there was some inteference problems.

I love my drop keel Bensen, If I can get my small shop cleaned out where I can work again, I will build another one. Hopefully with the Weber engine.
 
Last edited:

wingwalker

Newbie
Joined
Oct 12, 2010
Messages
3
Location
Detroit Lakes
mac electric flywheel

mac electric flywheel

Hey Steve, not sure, Marion bought the whole kit together. I will try and find out.
Hello I'm building a starter for my mac 72 hp and would sure like to know what the flywheel is off of in the pictures. It says a OMC or Johnson outboard motor. What HP engine and year of production would help. I'm also looking for a used prop for my mac which doesn't have to be airworthy. Any help would be apprieciated.
 

Friendly

Platinum Member
Joined
Jan 5, 2004
Messages
4,441
Location
Woodworth, LA.
Aircraft
KB2 & KB4
Total Flight Time
110
I did not try it, however, I think, Tom Miltons flywheel can be modified to fit the Mac hub and use a Ford 9 pinion tooth starter. That is the same style starter as on a Butterfly electric prerotor. (I think).
I am about to leave for a Flyin at Bastrop. If you have not found one when I return, I will see what I can come up with. The OMC was a 60s model I was told.
 

stolking1

Newbie
Joined
Jul 22, 2011
Messages
63
Location
Phoenix
I am looking at the drawings and I see two of the back plates (same)
One side plate and the corner blocks... I think there is another side plate missing.
The machine shop told me I needed the other side..
Would it be too much to ask for help in getting the other side?

Thanks JD
 

dabkb2

Dave Bacon
Joined
Sep 26, 2005
Messages
2,193
Location
Vista, Ca
Aircraft
2 KB2 90Mac KB3 582
Total Flight Time
289 hours
I am looking at the drawings and I see two of the back plates (same)
One side plate and the corner blocks... I think there is another side plate missing.
The machine shop told me I needed the other side..
Would it be too much to ask for help in getting the other side?

Thanks JD
JD, you might have to fabricate on yourself. It should not be all to hard, just bolt up what you have take some measurements and make a new side plate. There might be someone on here that has one to copy.
 

Friendly

Platinum Member
Joined
Jan 5, 2004
Messages
4,441
Location
Woodworth, LA.
Aircraft
KB2 & KB4
Total Flight Time
110
the Two plates in post 23 ARE the Side plates. The blocks attach to the inside of the side plates and allow some adjustment in the slotted holes.

The two images in post 22 are the same picture. I did not think the first one uploaded , so I uploaded it twice by mistake.

the plate in Post 22 bolts to the two side plates. and the starter goes through it to engage the flywheel. Do not use the Ford starter in the pictures as the snout is too long. Use a Ford 2000 legacy type starter and you should be able to make it work well.
 

Friendly

Platinum Member
Joined
Jan 5, 2004
Messages
4,441
Location
Woodworth, LA.
Aircraft
KB2 & KB4
Total Flight Time
110
I apologize, there is only one side plate. I have looked on my computer and have not found the images yet.

If you print out the pictures you should be able to cut one out of cardboard and put up on your mac.
Then mark where it extends toward the prop. Take it off and put it on the other side and see what the difference is . the sides were the same except the length from the cylinder bolts was a little different. then transfer the difference to a new sheet of paper and you should have your template to cut in Alum.

Does that help ?
 

jcarleto

Aluminum Supporter
Joined
Jun 5, 2007
Messages
3,571
Location
Taylorsville, GA
Aircraft
Beech Bonanza G-35 N4638D/"The Bulldozer" 2-Place Gyroplane N575EE
Total Flight Time
Several
Thanks, Dave!
 
Top