90hp brownband merc

J

jamiebrant

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Joined
Oct 30, 2010
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11
i just bought a brownband mercury 90hp inline 6 for my 16ft runabout.motor looks to be in vgc but in sayin this what are these engines like reliability wise and do they have wiring issues or what are common problems that happen and how to tell this .i just want to sort out any issues before i take it out there and find out the hard way.
cheers
 
C

Chris1956

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Mar 25, 2004
Messages
27,142
Re: 90hp brownband merc

Those motors are a classic, successful design. If it were me, I would inspect the carbs to make sure they are clean, inspect the wiring to make sure it is good, inspect the gearcase for leaks and chnage the gearoil and replace the waterpump impeller, wearplate and gaskets. Now check link and synch
 
A

arsenalpsu

Petty Officer 1st Class
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Dec 1, 2008
Messages
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Re: 90hp brownband merc

Also do a compression test, should be +/- 10-15% of eachother
 
Cadwelder

Cadwelder

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1,780
Re: 90hp brownband merc

I've ran a 1987 In line 115 since it was new, it's been an extremely dependable engine. Only things that have been replaced in 23 years is a stator and fuel pump,and a couple of rectifiers, other than normal maintenace. That's a pretty darn good record in my book.
 
bktheking

bktheking

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Re: 90hp brownband merc

Brownband with oil injection? The only thing I've been told is disconnect the inj and run mix.
 
redjmp

redjmp

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Mar 16, 2005
Messages
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Re: 90hp brownband merc

bktheking said:
Brownband with oil injection? The only thing I've been told is disconnect the inj and run mix.
Click to expand...

I totally agree!

Also they don't like being lugged so make sure you prop it so that it hits at least 5500 wot and try not to run too long under 3000rpm.

But don't run it at wot for too long. It will run forever at 4200.

My '86 115 gets a best cruise @ 3150 @2.45 l/km at 44 km/h. 2.2km/l @ 4200.
 
J

jamiebrant

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Joined
Oct 30, 2010
Messages
11
Re: 90hp brownband merc

hey thanks heaps for that i was shown compression 125psi with a 5psi variation beetween 3 cyl and everything else is ok besides one wire for the til trim i was a bit worried at first because a couple of people have told me that they are aspirins (they dissolve in water) from corrosion and you will have nothing but trouble. Now im thinking differently.ill post some pics soon from Australia
cheers
 
Z

zac1954*1

Recruit
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May 22, 2011
Messages
3
Re: 90hp brownband merc

I also have a 90hp brownband merc serial no A701650. Can anyone tell me when in the
'80s it was manufactured?
 
Gomer50

Gomer50

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Sep 5, 2009
Messages
507
Re: 90hp brownband merc

Now I run a 1978 90hp inline 6 and according to the book these motor run between 4500 rpm and 5000 rpm not sure if that was changed in the 1980's dont want to over rev,. her.
 
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