1987 Merc V200 and 1990 Merc V175

fmeroney

Cadet
Joined
Mar 19, 2011
Messages
15
Trying to figure out if I can swap the 175 powerhead for my 200, its junk. and get the 175 to be a 200?

What are the differences Carbs? I know the reed block is different but does that matter? Otherwise it looks like the same 2.4l I think the pistons are the same too.
 

1nebel0

Chief Petty Officer
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Nov 28, 2005
Messages
512
Re: 1987 Merc V200 and 1990 Merc V175

yes you can do ther swap...The carbs could be the same....however the jetting needs to be different for the 200h.p. Keep in mind also that the main jets along with the idle air jets are different on different cylinders.. You need the factory manual to know what goes where....you also need to know the carbs feed opposite cylinders. That alone can get confusing... I made a chart and wrote on it what jets went where to keep it straight... The jetting is smaller on the 175 versus the 200 so you need the manual...
 

CharlieB

Vice Admiral
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Apr 10, 2007
Messages
5,617
Re: 1987 Merc V200 and 1990 Merc V175

You may want to verify the part #'s of both engines serial numbers, I beleive you will find a difference in the port timing of the two motors, meaning a different part #.

What is wrong with the 200? Why is it "junk"?
 

fmeroney

Cadet
Joined
Mar 19, 2011
Messages
15
Re: 1987 Merc V200 and 1990 Merc V175

Long story short......

I bought a 87 Ranger Bass boat for a restoration It has a 1987 Mercury V6 200, It was dirt cheap but had a motor issue. Tore it apart and found the problem the oiler gear was spun! So it looks as if she seized. I did get a new six pack of Wiseco Standard Pistons from the previous owner with the deal.

Sent the block to USChrome, got the call from Mark and the news was that the bores were out and he would need to go .030 over. Here's my questions

1. Should I rebuild the PH with new .030 pistons (almost 1k just for bore and Chrome) and try to sell my Wiseco's ( Currently on Ebay http://cgi.ebay.com/ebaymotors/ws/eB...:MESELX:IT )

2. If so what pistons are good for a stock rebuild? Merc, Vertex, Wiseco??

3. There are some donor Powerheads some are 200's and some 175's. Can I use a 175 Powerhead for a 200 rebuild? What are the differences Crank, pistons, Reeds?
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,931
Re: 1987 Merc V200 and 1990 Merc V175

What are the differences Carbs?
The differences are: port timing on intake and exhaust and carbs.
Sent the block to USChrome, got the call from Mark and the news was that the bores were out and he would need to go .030 over.
Not worth it on a 2.4 block and nobody makes a .030 ring to run in a rechromed/nicasil block. I think you may have misunderstood him and they are sleeving block.
Should I rebuild the PH with new .030 pistons (almost 1k just for bore and Chrome) and try to sell my Wiseco's
No as you can find a 2.5 block for less than $1000 and sell the pistons...
If so what pistons are good for a stock rebuild? Merc, Vertex, Wiseco??
Pro,Vertex (if you can find some a stock is slim)WSM,Persan Merc and Wiseco if was last option.
There are some donor Powerheads some are 200's and some 175's. Can I use a 175 Powerhead for a 200 rebuild? What are the differences Crank, pistons, Reeds?
Only difference is carbs(internal plumbing) and the time area(porting) on the intake and exhaust. If the 175 is a good block and only needs STD piston send it to Mar-Fab and have it ported to a 200, as this is cheaper than sleeveing.
 

fmeroney

Cadet
Joined
Mar 19, 2011
Messages
15
Re: 1987 Merc V200 and 1990 Merc V175

Well I just called a guy who sells Vertex and he has .030 2.4l with chrome rings... There out there. Im sure someone whould make them if USchrome will do the work. Also, USchrome will sell you pistons for it too....
 
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