Merc 200 – Rebuild or not?

[willp2]

I have recently acquired a mid 1980’s Blackmax 200HP motor. The motor runs but has a bad rod bearing. I have been planning on rebuilding the motor myself, but I talked to a mechanic who tells me that it is very likely that the crank is shot and will need to be replaced. Also, since this motor has chromed sleeves it will probably need to be re-chromed or replaced with a newer block.

So basically if all that’s true, I’m going from a nice affordable driveway rebuild to effectively buying a new (rebuilt) powerhead.

I’d appreciate any comments on the assumption that the crank is bad and not repairable as well as it being a given that the chrome sleeves are toast.

Thanks for any input!

 

[WillyBWright]

Re: Merc 200 – Rebuild or not?

If the crank is toast, you'll need a new one. They can't be repaired. If the block has chromed bores, the block can be re-chromed, or bored and steel sleeved. You would only have to sleeve the damaged one(s). The expense involved to do all that would justify replacing the powerhead with a professionally remanufactured one. Had it been either/or instead of both, I might have advised differently.

 

[willp2]

Re: Merc 200 – Rebuild or not?

Thanks for the input, that’s about how I was seeing it as well.

The question I was really getting at was should I assume that the crank is toast because I have a bad rod bearing? And should I assume that the one or more cylinders need re-chroming / sleeving based on its age? This guy is a good mechanic, but he did not open the motor up, he’s basically telling me that more than likely the crank is shot because of the bad bearing and the cylinders need relining because it’s got 650+ hours on it.

Guess I’m just hoping he’s being greedy and wants the work

 

[bigshrimpin]

Re: Merc 200 – Rebuild or not?

I have recently acquired a mid 1980’s Blackmax 200HP motor. The motor runs but has a bad rod bearing. I have been planning on rebuilding the motor myself, but I talked to a mechanic who tells me that it is very likely that the crank is shot and will need to be replaced. Also, since this motor has chromed sleeves it will probably need to be re-chromed or replaced with a newer block.

So basically if all that’s true, I’m going from a nice affordable driveway rebuild to effectively buying a new (rebuilt) powerhead.

I’d appreciate any comments on the assumption that the crank is bad and not repairable as well as it being a given that the chrome sleeves are toast.

Thanks for any input!

It never hurts to get a second opinion . . . especially when someone is telling you that the block need to be rechromed after 650hrs. That's not true at all. These motors go thousands of hours. As long as the chrome isn't peeling/flaking you're fine. Little holes and pits are normal in the chrome bore motors. USCHROME is the place to send your block if you want to rechrome one cylinder.

 

[willp2]

Re: Merc 200 – Rebuild or not?

great, so it's definetly worth my time to at least tear the thing apart and have a look.

As far as the crank goes, how do I know for sure if its toast? do I need to take it to a good machine shop and have it checked out?

Also, if I do rebuild this thing myself are there many special tools needed beyond what it would take to rebuild a car engine?

Thanks!

 

[WillyBWright]

Re: Merc 200 – Rebuild or not?

If a rod bearing is toast, the crank is toast. Knocking the block apart doesn't take that long after the stuff on it is removed, which would have to be done either way. It's worth it to do it.

 

[willp2]

Re: Merc 200 – Rebuild or not?

OK, that's what I was wondering. Considering I have to at least buy a new crank, and maybe re-chrome / re-sleeve am wondering if it makes more sense to buy a rebuilt powerhead?

I’d much rather rebuild, but from the few prices I’ve seen around it looks like I’m into around $800-$1,100 for a crank and about $1k for a rebuild kit.

And I have seen rebuilt powerheads for $2300-$3000. So potentially I could get a rebuilt ready to go powerhead for not all that much more. Are my numbers way off?

Again I’d rather do this myself, but is the financial savings really there? It seems like it should be.

Thanks again for all the great feedback!

 

[halibob]

Re: Merc 200 – Rebuild or not?

When i had the swivel pin and steering arm and bushings replaced on my 89's, ( it was docked in salt water for several years), they had a bear of a time removing the powerhead from the midsection on one of the engines because it was fused together, so you're gonna have to liquid wrench the heck out it, and maybe even drill holes to get some on some of the studs, and later fill those holes, so beware that it could be a tough job just to get it apart, and not meaning to change the subject, but where can a guy get rebuilt power heads for those engines? Thanks , bob.

 

[halibob]

Re: Merc 200 – Rebuild or not?

And don't forget to use a thread antiseize compound on the threads during reassembly.

 

[willp2]

Re: Merc 200 – Rebuild or not?

Yikes, I hope I don't run into that. Thanks for the tip. As far as the rebuilt powerheads, one this place is one of the links up on the right side of this page:
http://www.boatmotors.com/motorparts/
I'll see if I can find some of the other places that have them.

 

[imported_neecapr]

Re: Merc 200 – Rebuild or not?

Just because the "Avice Admiral" has a spot on this board doesn't make him an expert. He's hopelessly ignorant of the facts!
Crankshafts can be repaired, even by our closest competitor!! They're running and winning enough races to prove that!
There are two companies that provide extraordinarily high quality repair on crankshafts. One is Marine Crankshaft in Orange county, CA. They warranty their work for one year and do all journals, except top rod journals on small block Mercs and Mariners. You can find them on the web. With their track record, it's stupid to argue that crankshafts can't be repaired.
We are the other company. We do all journals and give a two year warranty on all of our work. We can be found at www.neecaprercisions.com. Ask Paul Moir about our work!
The "Admiral " needs to get with it and get beyond the lousy track record of Outboard Crankshaft Company in Washington state.

 

[imported_neecapr]

Re: Merc 200 – Rebuild or not?

Website address:
NEECA webaddress should have been neecaprecisions.com.
Regards, NEECA Happy Hour Manager!!'