Interchanging '81 to an '89 merc 200

[gregcooper]

I have a 1989 Black Max 200hp with chrome cylinders. Due to stupidity (not mine) the motor overheated and needs repair/replacement. I have located a 1981 powerhead that is a 200hp and need to know if this powerhead will bolt up to my '89 engine. Any answers?

 

[sschefer]

Re: Interchanging '81 to an '89 merc 200

I have a 1989 Black Max 200hp with chrome cylinders. Due to stupidity (not mine) the motor overheated and needs repair/replacement. I have located a 1981 powerhead that is a 200hp and need to know if this powerhead will bolt up to my '89 engine. Any answers?

Maybe DD is listening and can chime in.. I think you need to use the 89 exhaust plate but otherwise I think they're the same.

So how bad is the chrome. You can get them re-done. That 89 is supposed to be a sweet block. Do you know if it's a seven petal front half?

 

[gregcooper]

Re: Interchanging '81 to an '89 merc 200

The machine shop said that two cyls. are scratched "deeply" and they could not rebone due to thin cylinder walls. I don't have any idea how many petals it has, but would look if you can tell me what they are. I have also investigated rechroming ($815) and am looking into that, but the cost of the attendant parts and labor to install seems to make this option almost as expensive as a reman.

Thanks for the exhaust plate idea--will ask my tech. If any other info needed let me know, and thanks so much for your help. Hope to talk with you soon.

Greg

 

[sschefer]

Re: Interchanging '81 to an '89 merc 200

Can you get me the serial number on that motor? I may be able to help you decide. I've got this funny feeling you're going to be far better off fixing the 89. I've put some feelers for info out. If you can hold off on your decision for a bit I'll have more info for you soon.

 

[sschefer]

Re: Interchanging '81 to an '89 merc 200

Got a little more info, not that special. You could do a budget go fast motor (3-4 grand) and get 240 hp under the bucket if you wanted but if that's not in your plans then maybe the 81 is a better option if it doesn't need a rebuild too.

Personally, I'd be looking for a 91 or better if for nothing more than parts availability and a 2.5L Block. I've got a 99 200 I'll be doing this winter. Got to get the FrankenMerc project done first.

 

[Faztbullet]

Re: Interchanging '81 to an '89 merc 200

It a direct swap and you dont have to change anything. You DO need to rejet the engine to make it live due to fuel issues. Up the high speed jets .002 on each cylinder as there a Merc bulletin on this issued in the early 90's. Also you can have the block resleeved no matter how deep scratches are but it cannot be bored just replated. The company up north that rechromes them does not use chrome anymore ,they use Nicasil..

 

[gregcooper]

Re: Interchanging '81 to an '89 merc 200

Great! This can solve my problem. I really appreciate your input and wish I were hundreds of miles closer so you could do the work. Only one more query: is rejetting just a matter of boring the jets or replacing with bigger ones? I promise I won't bother you again unless I can send some business your way. Many thanks.

 

[Faztbullet]

Re: Interchanging '81 to an '89 merc 200

Your 1989 should have the same style carbs as the 1981,so just swapp the jets. Your 89 should have .080 and .082 high speeds and the 81 if not updated will have .076 and .078. Make sure the carbs are clean!!!
1395-6201 is part number for .080 jets and you will need 4 and 1399-3518 is part number for .082 and you need 2.