First Boat with 90HP Evinrude

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surrender

Petty Officer 1st Class
Joined
Jan 25, 2009
Messages
393
Re: First Boat with 90HP Evinrude

Shezwet said:
Also does anyone know where I will find the Alternator unit on this motor? thanks!
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No alternator. Charging is through the stator. I think yours has the rectifier like mine. Maybe three wires, two yellow and one red. Somewhere on this site is a good test procedure to see if it is charging properly. Mine charges to good. Its not regulated so during long runs the battery can become over charged without any accsesories running(radio, lights,ect). Iam looking for a regulated one to replace mine.
 
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jhebert

Ensign
Joined
Jul 24, 2005
Messages
902
Re: First Boat with 90HP Evinrude

Your motor has a permanent magnet alternator. For more information see:

Permanent Magnet Alternators
http://continuouswave.com/whaler/reference/PMA.html

A good procedure to use when checking out a used outboard motor is given at

Assessing Used Outboard Motors
http://continuouswave.com/whaler/reference/outboardCheck.html

There are no electronic documents available for download on line at no charge which contain anywhere near the information available in a printed factory service manual. If you want to work on your outboard motor you must purchase the factory service manual. People will help you with questions, but you need a service manual if you are really interested in performing service work.
 
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Shezwet

Seaman Apprentice
Joined
Jan 17, 2010
Messages
33
Re: First Boat with 90HP Evinrude

Thanks guys - I honestly done have enough money at the moment, As my work contract is coming up for renewal. So until then i need to do this by myself And save as much money as possibly. If I do a compression check tonight What should This be reading? I have done a quick search but havent found anything. I know all should be about 10% within eachothers readings. But yeah I need to know what they should be reading also, And what the voltage across the battery should be reading out when the engine is running.

thanks.
 
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ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: First Boat with 90HP Evinrude

When those are running well, warmed up, with adequate lubrication and good rings, they will generally test above 120 psi at sea level.

The battery voltage should test above 12.7, rising as the RPM rises.
 
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Shezwet

Seaman Apprentice
Joined
Jan 17, 2010
Messages
33
Re: First Boat with 90HP Evinrude

Ok ok ok, you guys are so far my number 1 heros!!!! So - I got home, Chuicked the jumper cables on my car and jumped the boat battery. Wound over nice and fast which i was happy with!! WOOHOOO!!!! ( without the plug leads on or fuel line on but leavin the plugs in :) ) so after that I decided to give her a bit of a fire upp, Attached the leads and the the fuel line Bang started right away, Battery was down to 12.2v while the motor was getting up in the revs. So Somthng is wrong with the charging unit. Hopfully this fix's the battery dieing problem. I Havent done a compression check but i can garuntee that the bottom right cylinder bank is down on compression. What would be the most likely scenario for this?? rings or headgasket? I also couldnt see anything wrong with the piston and couldnt seen any scoring on the cylinder bores ( from the teeny tiny bit i could see from looking through the plug holes.

Ths spark plugs I installed were NGK BR7HS-10 Are these far too hot?

Thanks guys - Also Would there possibly be a fuse running from the rectifier to the battery?? I doubt it would be that easy but hey who knows!
 
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emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: First Boat with 90HP Evinrude

When you take a compression reading and find one cylinder down more than 10%-15%, that cyl becomes suspect. You would probably want to pull the head on that side, perhaps the intake side cover on that low cyl also-in order to see what is going on inside. Yes, it could just be a head gasekt. If you have cylinder scuffing, or piston damage, that's a bad sign. If the boat voltmeter shows 12.2 volts when running-the voltmeter is probably just reading normal batter voltage. It is probably not recharging the battery. Your 84 model had a combination rectifier/regulator assembly which may be bad. Is the tach still working in the boat? The only fuse on that engine is the one in the main harness, by the starter. It won't start without that fuse.
 
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Shezwet

Seaman Apprentice
Joined
Jan 17, 2010
Messages
33
Re: First Boat with 90HP Evinrude

thanks emdsapmgr!! :) Will be doing the comp test on Friday night! And Will need to track down a recitifer/regulator combo! From when I looked at the Tach last it does work on the boat. Is it a big job to remove the block? Thanks.
 
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emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: First Boat with 90HP Evinrude

If you have a tach reading, the voltage regulator/rectifier may be ok-since it drives the tach. I'd use the factory manual to test the output before you rush out to purchase one. Make sure the battery will take a charge. To pull the block, you've got to remove the lower cowling covers to expose the powerhead bolts. There are a combination of long bolts, and some small nuts which have to come off to release the powerhead. In addition, you wil need to disconnect the shift linkage to the lower unit under the bottom carb. A typical wheel puller mounted to the flywheel top can be used to grab the powerhead with a lifting device. A couple of hours and you can have it off.
 
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jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,174
Re: First Boat with 90HP Evinrude

So I guess you skipped getting the manual, it would really help you immensely, its the best $50 you can spend on your engine bar none .
www.outboardbooks.com
 
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Shezwet

Seaman Apprentice
Joined
Jan 17, 2010
Messages
33
Re: First Boat with 90HP Evinrude

I will end up getting one. But I have to wait another 3 weeks to see if I get a new contract here at work. As my profession is not easily available to find another company
 
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Shezwet

Seaman Apprentice
Joined
Jan 17, 2010
Messages
33
Re: First Boat with 90HP Evinrude

YAY!! Had a compression test done 120 PSI across all 4 DEAD even!!! I think im pretty happy with that for an old motor :) - How would I check the fuel pump is working correctly? thanks!
 
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