Thermostat clogged up

[acdc96]

I recently aquired a 1988 Nissan 18hp outboard from my cousin. The engine runs not the best but I'm in the middle of a carb rebuild. When going through the cooling system the impeller was completely shot. I ordered a new one and installing it this afternoon. I took of the thermostat housing and it looked corroded and filled with mud or dirt. I took the stat off and put the cap back on the housing without the thermostat. The Nissan service manual suggested if the motor was run in muddy, low water level, or in saltwater it should be ran without the thermostat in. Then remove a screw that flushes then motor when done. Is it wise to run the motor with out the thermostat??? I know in my other motors it's alright to run it in a short time but I don't to mess this up. Opinions???

 

[TOHATSU GURU]

Re: Thermostat clogged up

It's not a good idea. Invest in a trashcan and 20 gallons of vinegar and run it at an idle for a few hours to clean out the system.

 

[acdc96]

Re: Thermostat clogged up

K will do

 

[pvanv]

Re: Thermostat clogged up

What crazy manual suggested running without the stat? The motor will run too cold, will foul plugs.

First flush with clean water. If still restricted, flush with vinegar as Elvin suggests.

 

[Sea Rider]

Re: Thermostat clogged up

Was that engine used on fresh or salt water to start with ? Get rid of any thermo is one of the stupid word of mouth fallacies passed from unskilled pseudo tech mechs to boaters. A thermo is important specially if engine runs in cold water all the time.

Happy Boating

 

[acdc96]

Re: Thermostat clogged up

The official Nissan Outboard Owners Manual. From Nissan Marine Outboards - Authorized Distributor Offering Outboard Motors, Technical Information, & Dealer Locations for the U.S. & Canada." they have all the owner manuals for the nissan outboards. I got the nissan parts manual online for free from another website.

The parts manual website:
https://www.nissanoutboardparts.com/Parts-Books.html

The owners manual website:
Nissan Marine Outboards - Authorized Distributor Offering Boat Motor Products, Technical Information, & Dealer Locations for the U.S. & Canada."

 

[pvanv]

Re: Thermostat clogged up

The official Nissan Outboard Owners Manual. From Nissan Marine Outboards - Authorized Distributor Offering Outboard Motors, Technical Information, & Dealer Locations for the U.S. & Canada." they have all the owner manuals for the nissan outboards. I got the nissan parts manual online for free from another website.

The parts manual website:
https://www.nissanoutboardparts.com/Parts-Books.html

The owners manual website:
Nissan Marine Outboards - Authorized Distributor Offering Boat Motor Products, Technical Information, & Dealer Locations for the U.S. & Canada."

If you are referring to the flushing procedure on p23 of the owner's manual, understand that the procedures are for FLUSHING, not to permanently remove the stat.

The parts catalog does not tell you how to do any service work; it just identifies parts with exploded diagrams.

If you get a Factory service manual, much will become clear.

If these things seem confusing, please get help before you cause more problems than you are ready to fix -- either from a friend with more knowledge and experience, or see your local Tohatsu/Nissan dealer.