S2 9.2A, Replacing my A4 with Diesel - Advice Appreciated

[kevin_in_dc]

My new-to-me '77 S2 9.2A needs its Atomic-4 engine replaced. I don't want to get into a gas-vs-diesel debate here. I've researched rebuild and Moyer options, and after some consideration, I've decided to go diesel. I've already agreed to purchase a Yanmar 3GM30F (w/ full wiring harness and gauges) next Friday.

Has anyone performed this swap before, and if so can you provide some recommendations and lessons-learned from your own (or friend's) experience. Here are some questions I have off the top of my head:

1) I'm working with a marine mechanic. What are some tests he should perform on this engine, prior to me executing the purchase and picking up the engine?

2) Will the stringers in my 9.2A fit the Yanmar? What modifications might I need to make, and how long will those modifications take to perform? What are some shortcut modifications that I should avoid, in case they are recommended to me.

3) I understand that a diesel tank requires a return inlet that my current gas tank doesn't have. Should I try to clean and install a return inlet in the existing fuel tank (after emptying and allowing the tank out air-out a few days), or should I simply look for a a used diesel tank?

4) Recommendations for new prop with the 3GM30 in this boat?

5) I've been told that my existing A4 throttle/reverse controls will need to be replaced with something compatible with the Yanmar. Any recommendations on make/model? Any recommendations on vendor/length for replacement throttle cables? I'd like to have those on-hand before next weekend.

6) Anything else I'm not thinking about.

My plan is to pull the A4 next weekend, and immediately test fit the Yanmar to see what'll be necessary. I'll then set the Yanmar aside in the back of the cabin, so that I can clean and repaint the engine bay, perform any rewiring, etc. I'd appreciate any lessons-learned or advice on extra parts I should have. I will have a marine mechanic performing the work, with me as the helper (flashlight holder), but I'd like to begin the job with as many parts on hand as necessary to avoid interruptions.

Thanks,

Kevin
'77 9.2A

 

[woodster]

My new-to-me '77 S2 9.2A needs its Atomic-4 engine replaced. I don't want to get into a gas-vs-diesel debate here. I've researched rebuild and Moyer options, and after some consideration, I've decided to go diesel. I've already agreed to purchase a Yanmar 3GM30F (w/ full wiring harness and gauges) next Friday.

Has anyone performed this swap before, and if so can you provide some recommendations and lessons-learned from your own (or friend's) experience. Here are some questions I have off the top of my head:

1) I'm working with a marine mechanic. What are some tests he should perform on this engine, prior to me executing the purchase and picking up the engine?

as far as the engine is concerned have them run it on the pallet before you buy it

2) Will the stringers in my 9.2A fit the Yanmar? What modifications might I need to make, and how long will those modifications take to perform? What are some shortcut modifications that I should avoid, in case they are recommended to me.

you may have to rework the bed rails in order to get the proper angle for your prop shaft to work ...there is an article i think on aligning the prop shaft and stern tube by mail sail and also Tommays

3) I understand that a diesel tank requires a return inlet that my current gas tank doesn't have. Should I try to clean and install a return inlet in the existing fuel tank (after emptying and allowing the tank out air-out a few days), or should I simply look for a a used diesel tank?

you can get the weld fittings for best fab in florida if your tank is aluminum and in good shape use it but be careful of welding on a used gas tank

4) Recommendations for new prop with the 3GM30 in this boat?

you can contact a prop company about what prop you will need and what size they will calculate it for you

5) I've been told that my existing A4 throttle/reverse controls will need to be replaced with something compatible with the Yanmar. Any recommendations on make/model? Any recommendations on vendor/length for replacement throttle cables? I'd like to have those on-hand before next weekend.

you may need to change the end fittings if they are mores or teleflex cables or you may have to order new ones altogether but you really need the engine installed and set before you worry about that just yet ...this is going to take a lot longer than you think unless you have a big budget to spend things are not going to happen as fast you you may think so take a breath of fresh air and slow down some so you don't set yourself for disappointment

6) Anything else I'm not thinking about.

My plan is to pull the A4 next weekend, and immediately test fit the Yanmar to see what'll be necessary. I'll then set the Yanmar aside in the back of the cabin, so that I can clean and repaint the engine bay, perform any rewiring, etc. I'd appreciate any lessons-learned or advice on extra parts I should have. I will have a marine mechanic performing the work, with me as the helper (flashlight holder), but I'd like to begin the job with as many parts on hand as necessary to avoid interruptions.

you will also have to rework your prop shaft if it is useable or get a new one

Thanks,

Kevin
'77 9.2A

good luck

 

[kevin_in_dc]

Re: S2 9.2A, Replacing my A4 with Diesel - Advice Appreciate

Hi Woody,

Thanks for all the advice. All of it is appreciated. The boat is > 3 hours away, so I'll have my local mechanic inspect the engine, as you suggested, prior to traveling again next weekend. I'll probably ask to see it running myself when I arrive down there, but I do trust the mechanic.

Kevin