Inline 6 115 overhaul: Do it myself or let the pro do it?

[deerhuntre]

Why the conundrum? My main concern is getting the pistons back into the block, especially without breaking a ring and not knowing it. (Are there other problem areas in this rebuild job I should know about??)

For the past 12 years I've been my own auto mechanic and have completed some fairly complex repairs. I am quite comfortable and am really considering doing this, but I know the pros are familiar with the nuances that help move the process along easier and can better avoid problems because of their experience.

If I do the work myself, I was thinking I should spend the money and buy all new pistons, rings, bearings, and bore all six holes. If I have the pro service the block, I would have them reuse any pistons that may still be good and only bore where it really needs boring. Additionally, I would of course pay for the new rings and bearings.

I look forward to your comments.

 

[Chris1956]

Re: Inline 6 115 overhaul: Do it myself or let the pro do it?

Deer, An outboard rebuild follows the same basic principals as any engine. If the bores are worn or scratched, have them rebored and install oversize pistons and rings. Pistons are not cheap. Expect to pay about $100 per piston, rin and pin set and $30/hole to bore. You can hone and rering the good bores. Installing the pistons and rings is not hard. However, you motor likely has uncaged roller bearings for the connecting rods crankpin and needle bearings for the wristpin. You need to stick 'em in with grease while assembling the crank-rod-piston assembly. I have found it very difficult to install the pistons and rods into the bores, if they are still attached to the crank.

The real challenge comes in making sure the motor is properly tuned after the rebuild, or it will (of course) destroy itself. This means the carbs need to be clean and adjusted properly, the ignition timing is properly set and synchronized to the carbs and the cooling system is working properly.

 

[deerhuntre]

Re: Inline 6 115 overhaul: Do it myself or let the pro do it?

So are you suggesting to install the pistons into the block first, then attach them one by one to the crank?

 

[Stinkin_V8]

Re: Inline 6 115 overhaul: Do it myself or let the pro do it?

I'm a boating newbie with a car background as well. I've rebuilt engines, swapped big engines into places they shouldn't belong, retrofitted modern factory fuel injection and built wiring harnesses for said. Even swapped old bodies onto modern chassis. Not bragging, just saying I'm in the same "boat" as it were.

I took some advice from other forum members and did a search for Clams Canino. His email address is in his posts. After talking to him on the phone, I sent my 1980 90hp I6 powerhead to him to rebuild. I'm sure I could have done it myself (eventually) but now I can focus on the lower end and still have a shot at having it in the water this summer.

Good luck in whatever you decide!

 

[deerhuntre]

Re: Inline 6 115 overhaul: Do it myself or let the pro do it?

Yeah, I was afraid this is what the response would be!! I have spoken with Wayne and he's really great! That is likely the route I will select, but I just wanted some input to help me decide.

Thank you!!

 

[Stinkin_V8]

Re: Inline 6 115 overhaul: Do it myself or let the pro do it?

Yeah, not saying it would be easy for me to rebuild it, I've never worked on a 2-stroke. But Wayne makes it so easy to be lazy!

 

[Chris1956]

Re: Inline 6 115 overhaul: Do it myself or let the pro do it?

Deer, You either need to install the pistons into the bores, and attach one-by-one to the crank, use the six ring compressers (special Mercury tools), or rig up some kind of jig to hold the crank in the correct position (a few inches above the block), and install the pistons while they are attached to the crank. I never wanted to buy the special tools, and never could get the jig to work, consequently, I did it the low-tech way, piston by piston, roller bearing by roller bearing.

 

[Scaaty]

Re: Inline 6 115 overhaul: Do it myself or let the pro do it?

I just had a Pro old inline 6 Merc guru do my inline 135 crank up. I been wrenching for years, but this best left to someone who has done inline Mercs...not much involved (keep the good pistons, hone/re-bore what needed, new bearings, rings, seals..check all plates for flatness,), but its the little things (link/sync/timing) that comes from experience that will have you with a sweet running motor done by a pro, or if ya do it yourself, and set one little thing wrong, it could be an expensive lesson