1974 Starcraft 18' runabout w/3.0 140HP 4-cyl. *So many Questions*

WanderingWolf

Recruit
Joined
May 5, 2021
Messages
3
Hi all... New boat ( First one for me!) that is a total mess and I'm digging in and trying to start the repair process. Bought this last summer for $100 and am somewhat using it as a testbed as I just completed boat school and am now an ABYC/NMEA certified marine technician/electrician. Hoping to make a decent little crabbing/shrimping/tooling-around boat for the waters here in the PNW.

1. Tips on how to change the engine belt? I know I have to block/jack the motor and remove part of the mount. Just looking for any helpful tips.
2. How to find new/refurbished parts? Have a couple of parts (#60372, #47587) that need replacing and the local Mercury shop said they'll be impossible to locate due to age.
3. Tried to engage my throttle today (Which I'd done previously without issue) to test if the motor would turn over via the prop, and the handle broke off. Actually, the splined piece that comes out of the assembly behind the side panel that the lever attaches to broke off. It's toast, no repairing it. How do I find a replacement? Used, refurbished or new? Do I have to drill out all the rivets and remove the entire side panel to access this for repair/replacement?

Should I seriously consider just junking this motor and switch over to an outboard (thinking a 90-115 should be plenty)? I know that's a lot of work itself plus the cost of a (used) outboard which still isn't gonna be cheap. But, I am worried about being able to keep finding parts (that aren't used) as they wear out (they already are), the age of the motor, the condition which is still unknown, and the amount of rust (large chunks and flakes) I've already seen inside the cooling system.

Outboard question; If I do switch over, do I need the trim tabs on my boat now or are those only needed with the I/O? They're aftermarket and seem to be in decent condition still.

I bought a lot of tune-up parts this week, but after that throttle lever broke today and learning I have to take apart the motor mount to change the dang belt, I'm feeling a little defeated with the motor and am leaning towards tossing it and starting the process of redoing the boat with the plan to add an outboard...which would free up some real estate inside the boat and allow me to add some storage.

Talk me into keeping the 140? Talk me out of it? Tell me how to fix, repair, and find parts? Tell me I'm stupid for buying a $100 hole in the water? Send me memes to lift my spirits? Drink a whisky with me?

Okay okay...seriously, looking for help, tips, advice, opinions, whathaveya. Thanks in advance!
 

Attachments

  • boat throttle lever-1.jpg
    boat throttle lever-1.jpg
    1.5 MB · Views: 6
  • boat throttle lever-2.jpg
    boat throttle lever-2.jpg
    1.2 MB · Views: 6
  • boat throttle lever-3.jpg
    boat throttle lever-3.jpg
    1.1 MB · Views: 6

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,534
1. Tips on how to change the engine belt? I know I have to block/jack the motor and remove part of the mount. Just looking for any helpful tips.

Usually easier to remove the lag bolt rather than the mounts themselves. People when replacing the belt will often put a spare underneath the mount, so that it can be replaced next time without messing with the mount
2. How to find new/refurbished parts? Have a couple of parts (#60372, #47587) that need replacing and the local Mercury shop said they'll be impossible to locate due to age.

you might not be able to find oem, but aftermarket is a lot of times available. Barr Marine makes both of those parts, quick Google search found them. eBay is your friend otherwise.

Should I seriously consider just junking this motor and switch over to an outboard (thinking a 90-115 should be plenty)? I know that's a lot of work itself plus the cost of a (used) outboard which still isn't gonna be cheap. But, I am worried about being able to keep finding parts (that aren't used) as they wear out (they already are), the age of the motor, the condition which is still unknown, and the amount of rust (large chunks and flakes) I've already seen inside the cooling system.
No f'ing way. Buy a boat with an outboard. If you are married to the boat, much easier to replace with a full Stern drive package from a junk boat. What you absolutely, 100% should do before syncing a lot of time and money into this boat is making sure that the stringers and transom aren't rotted. Is this an aluminum starcraft?

Outboard question; If I do switch over, do I need the trim tabs on my boat now or are those only needed with the I/O? They're aftermarket and seem to be in decent condition still.
Most 18 footers don't need trim tabs
Talk me into keeping the 140? Talk me out of it? Tell me how to fix, repair, and find parts?
your biggest issue with the package you have is probably going to be in the outdrive itself, although I certainly don't know enough about the differences in the really old 3 l

Tell me I'm stupid for buying a $100 hole in the water?
Ummmm....
 

Alumarine

Captain
Joined
Feb 22, 2005
Messages
3,745
1. There's a removable block on the port side of the front motor mount that allows you to change the belt.
No need to block or jack it. It's a 10 minute job.
As nola mike said put a spare in there as well.

As far as trim tabs go, I use them on my 18 footer and others do as well.

front motor mount.JPG
 

WanderingWolf

Recruit
Joined
May 5, 2021
Messages
3
Usually easier to remove the lag bolt rather than the mounts themselves. People when replacing the belt will often put a spare underneath the mount, so that it can be replaced next time without messing with the mount
I was offered that advice about adding a second belt while I'm changing it. Looks like the swap is easier than I thought.
you might not be able to find oem, but aftermarket is a lot of times available. Barr Marine makes both of those parts, quick Google search found them. eBay is your friend otherwise.

Don't care about OEM, just goo quality, functional parts. Thanks for the heads up on Barr Marine. Ebay will be used parts for sure, but if they're better than my rusty junk, that's good enough.
No f'ing way. Buy a boat with an outboard. If you are married to the boat, much easier to replace with a full Stern drive package from a junk boat. What you absolutely, 100% should do before syncing a lot of time and money into this boat is making sure that the stringers and transom aren't rotted. Is this an aluminum starcraft?

Nope, no interest in buying another boat, but I get your point. I like my boat, the size, etc. and any boat around here in my price range will also need work. A used, NOT rebuilt, 140 Mercruiser 4-cyl. goes for $1k around here.
This is an aluminum boat so all my stringers are aluminum I believe from what I've researched. Could be wrong. Transom is solid, it's easily accessible and other than needing some fresh paint and backing plates on some hardware, it's good.
Most 18 footers don't need trim tabs

your biggest issue with the package you have is probably going to be in the outdrive itself, although I certainly don't know enough about the differences in the really old 3 l

Looks like your comment got cut off... The outdrive is in mediocre condition externally. It's missing a few bits. I'm replacing the impeller and changing the fluid. I'll go from there. Prop needs replacing, but not critical.
Ummmm....
 

WanderingWolf

Recruit
Joined
May 5, 2021
Messages
3
1. There's a removable block on the port side of the front motor mount that allows you to change the belt.
No need to block or jack it. It's a 10 minute job.
As nola mike said put a spare in there as well.

As far as trim tabs go, I use them on my 18 footer and others do as well.

View attachment 344969
Yep, guys at the Mercury shop yesterday told me to add a second belt, said just wire tie or zip-tie it in there.

Ok, so trim tabs stay. Good. Didn't want to remove them. They need new switches, but pretty sure they'll work.
 
Top