Thermostat Install in 1989, 88 Evinrude Sp.

jrcsped

Cadet
Joined
Aug 5, 2005
Messages
8
:( HELP PLEASE :confused: . I have a 1989 Evinrude 88 Special. Great little motor. My fuel mileage is terrible. Pushing an 18' Predator, 24 Gal. Fuel, 4 people w/total people weight of approx 750 lbs and another 150 gear. 17 Pitch cupped prop, 5400 rpm WOT, 28-30 mph and distance measured with a GPS and I am burning 24 gal of fuel in 50 - 52 miles of running. I am 2nd owner of motor. Original owner removed the thermostats. "Pee" stream NEVER gets hot, always cold. I was told the engine is probably not getting up to proper temp and this is having adverse effect on fuel consumption. I fish in the bay 50% of the time so it sees lots of saltwater. I do rinse for approx. 10-15 minutes upon return with "Muffs" and hope it is getting flushed good enough. My major fear about putting thermostats back in the motor is them getting stuck from the saltwater and burning up the engine. I am very good with car, truck engines, overhauled several. I have a manual for boat motor but cannot understand somethings (I think too many models in one book and not enough pictures, I am a very visual person) and without a diagram or picture showing exactly how the thermostat components go together, I am in trouble. I purchased a thermostat kit from iboats which has the springs, thermostat, seals, etc. but I DO NOT KNOW how it all goes together or in any particular order or sequence. If the old ones were there, I would see how it came apart and put it back the same way, no can do. Any help from anyone would be deeply appreciated. I have promised a fishing trip to a couple of boys in a few days and I am at a loss. Mr. Dhadley, member # 685. Sir it would appear you have been around for a while and probably have lots of experience. If you are still out there somewhere and could respond along with others who have any experience I truly would appreciate it very much. One last thing. If there have not been any thermostats in this motor for a while (I have owned and operated it for 2 years now) I am concerned about corrosion or salt build up around ports (holes) were thermostat is installed. When I open her up, do I need to be real concerned or critical about cleaning up the passage/ports down to good metal to help eliminate the possibility of problems after I install the thermostats? Does anyone know of a product that will help remove the salt build up inside of the motor? An inspection reveals what I think is a salt build up. Also, if anyone knows where I can get a picture of the order of assembly for the thermostat parts, that would also be appreciated. I have looked all over the internet and I am not having any luck. Thank you in advance for your help. jrcsped. :)
 

B.autry4711A

Petty Officer 2nd Class
Joined
Feb 24, 2005
Messages
176
Re: Thermostat Install in 1989, 88 Evinrude Sp.

Go to this link http://ww2.sierramarine.com/sierra/search/searchmain.html and look on the left side of the home page and click on the catalog and search for your thermostat kit and it will have a picture of it for you. I also have the same engine and I changed mine out last year. I have to go for now but I will be back later on tonight and see if you were able to find it o.k.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,544
Re: Thermostat Install in 1989, 88 Evinrude Sp.

Gonna bet your 88 is cross flow charged. In case you don't know what that means it means $$$$$$ outta your pocket. BTDT<br /><br />When OMC developed the Loop Charged (late '67, 55 hp 3 cyl) engine they increased the mpg at least 2:1. <br /><br />The 3 cyls started the revolution and the 6 cyls continued the tradition, (because a 6 was just 2 sets if 3 cyl tuned exhausts) but it took years for OMC and others to figure out how to tune the exhausts on 4 cyls which had to happen for the looping function to work.<br /><br />So you can fiddle with this and that, but you are not attacking the root cause of your bad mileage.<br /><br />Sorry, but facts are facts. Like I said BTDT, '72 cross flow 125 Johnny....had to tow the fuel barge behind me....Oh it would run it's arse off and at one time I towed 5 skiiers, but it was in love with the fuel tank.<br /><br />Having gone to current technology loopers, I can personally testify as to the difference and sir it is apparent and real.<br /><br />Mark
 

sycamore

Seaman
Joined
Jul 12, 2004
Messages
60
Re: Thermostat Install in 1989, 88 Evinrude Sp.

I have a 1988 88hp on a 20' aluminum jon. I can run about 38 with a cupped aluminum 17 pitch, WOT of about 5300. I recently got a 15 pitch to keep the WOT on the high end of spec. When you run WOT you will burn much more gas. Open it up and get it on plane, then back it off to about 23 or 24 mph. The timing advances and carbs open as you throttle up, but if you back off a little after reaching WOT, the carbs will close slightly and the timing will stay somewhat advanced. You can increase your range by about 30% or more and not notice just alot of speed difference. What you report is normal for WOT, but I think your prop is slipping alot, probably close to 25 or 30 percent if you are only running 28 mph. My jon gets on top of the water, you may be pushing alot.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Thermostat Install in 1989, 88 Evinrude Sp.

I agree with grandview on not running at WOT, but if you do you should expect to burn 16 gallons an hour more or less.<br /><br />You can help by using high quality lubricants top and bottom, flawless propeller, clean hull, good thermostats, balanced load and proper tilt and trim.<br /><br />Also there is no real difference in fuel consumption between fast acceleration in a car or in a boat...just like flushing a toilet.<br /><br />Salt-Away does a good job on sea salt that has built up. Using a landscape barrel instead of muffs will do better if there is a lot of it. Salt
 
D

DJ

Guest
Re: Thermostat Install in 1989, 88 Evinrude Sp.

1. Your WOT RPM should be a minimum of 5500. I would sugggest going to a 15" prop. You will not have to work the engine as hard to keep a heavy boat on plane. There is a HUGE difference in fuel economy between WOT and 3/4 throttle.<br /><br />2. The thermostat housing is at the back of the engine, between the heads, down low. It5 has two hoses attached to it. <br /><br />Replacing the stat's. on that engine is not really easy, but it can be done. It's allot easier if you drop the lower cowl pan down an inch or so. To do so, you need to remove the upper leg cover just below the cowl pan.<br /><br />As you remove the three bolts holding the housing on, BE CAREFUL-GO SLOW. You do not want to break those bolts.<br /><br />Also, be aware that there are springs and bypass valves in there. Take careful note of how they go back in.
 

jrcsped

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Joined
Aug 5, 2005
Messages
8
Re: Thermostat Install in 1989, 88 Evinrude Sp.

Gentlemen, thank you for all the feedback. A little correction to the original posting. I was reading the comments concerning the pitch of the prop on my boat when it dawned on this tired old mind, Dah - my current prop is a 15 pitch and not a 17 pitch.<br /><br />I have already purchased the thermostat kit but I just do not know the order in which everything goes back together. The motor did not have any thermostats in it when I purchased it, therefore I do not have one to look at to find out how it should go into the motor. I am looking for a picture on the sequence of the installation of the thermostats. Thanks jrcsped
 

jrcsped

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Joined
Aug 5, 2005
Messages
8
Re: Thermostat Install in 1989, 88 Evinrude Sp.

Big Bubba I went to the Sierra web site (that is also where I purchased my parts) and there is an exploded picture, but they still do not show the sequence of how the parts go together. I have two flat gaskets, two springs, two cork round gaskets, 2 white plastic valve reliefs, 2 black rubber grommets and 2 thermostats. My clymers manual does not explain (or I cannot find it) nor show a picture of how the parts go together. I need to know the specific order in which the parts line up together to install them. My motot DID NOT HAVE ANY THERMOSTATS IN IT WHEN I PURCHASED THE MOTOR. If anyone can help me with how these parts go together I would appreciate it very much. Thank you, jrcsped
 

jrcsped

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Joined
Aug 5, 2005
Messages
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Re: Thermostat Install in 1989, 88 Evinrude Sp.

Hey everyone, my future son-in-law just walked over and handed me the right page and picture in the clymers manual with a picture on how it goes together and explained it to me. I thought everything went together in two holes and he showed me how the thermostats go in the outside holes, while the spring and valve relief parts go in the two inside holes. It now makes sense. I guess I am just getting old, crazy or both. Sorry for any inconvienence I may have caused for anyone. Thanks again for all the input. jrcsped.<br /><br />They say, The LORD looks out for fools and old folks, I guess I'm in one category headed for the other. Thanks. jrcsped
 

KYHunter2

Chief Petty Officer
Joined
Mar 20, 2006
Messages
512
Re: Thermostat Install in 1989, 88 Evinrude Sp.

Dont be too hard on yourself. No one here minds trying to help. <br /> Its better to ask before hand, then to screw something up, and then ask, how to correct it. <br /> Besides the fact, a screw up on an outboard, can be expensive.<br /> <br /> Good-Luck,<br /> KYHunter
 

TD_Maker

Chief Petty Officer
Joined
Aug 31, 2005
Messages
564
Re: Thermostat Install in 1989, 88 Evinrude Sp.

I have a 89 Johnson 88 SPl as well on a 17.5 ft Whaler. Sorry to say this, but the fuel mileage on this engine is not very good, but I know it is alot worse when you are buried in the throttle.<br /><br />The T-Stats are a little difficult to replace only because of space limitations. holding the housing while pushing in the springs and keeping everything aligned is a pain in the a... But, I finally made it happen, and the engine ran much better with the T-Stats than without.
 

ryanrip

Recruit
Joined
May 18, 2009
Messages
1
Re: Thermostat Install in 1989, 88 Evinrude Sp.

i would like to know this sequence of install as well. not sure were the corks go. mine didn't have then in it. manual on the way but won't be here quick enough for me.
 

bankerjohn

Chief Petty Officer
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Mar 21, 2008
Messages
444
Re: Thermostat Install in 1989, 88 Evinrude Sp.

Is this what you're looking for?

198888hpJohnson-thermostat.jpg
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Thermostat Install in 1989, 88 Evinrude Sp.

Click the thumbnail for the Sierra diagram; it shows the numbers and parts for each component and which ones are for your engine vs. the earlier crossflow models.

The complete kit is Sierra part # 18-3673, available here at iboats.
 

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