2006 Yamaha Grizzly 660 water line connection

[David Cameron]

The small waterline insert for the hose that goes from the water pump cover to the thermostat housing has corroded off. I only need the insert on top and behind the thermostat housing that the hose goes over and can't find just the insert. It looks like it may be pressed in. I've have been told the entire motor housing needs to be replaced. The pic with the red line indicates where the hose and insert would be and the insert looks like the pic of the water pump  Any ideas would be really appreciated.

 

 

[Frank Angerano]

Not sure what edition your bike is but here is the parts diagram for that year.  It looks like it’s a small housing that has to be changed.  

I cant imagine finding a stem and having it pressed in let alone getting the remnants of the old stem out.  

 https://www.yamahapartshouse.com/oemparts/a/yam/5003925af870021f60a0da89/water-pump

This website may help you find the parts  

 

 

Edited August 7, 2019 by Frank Angerano

[Frank Angerano]

So @David Cameron I had some free time today to research your problem and found some information on your bike.  I also spoke to a buddy of mine who is an atv mechanic at my Honda/Yamaha dealer as to a possible solution.  He also confirmed my findings. 

That thermostat housing is in fact casted into the cylinder head.   Not the motor housing or casing. 

Terrible design I would think on Yamahas behalf since that is a pressed in hose connector into that cylinder head made out of a galvanized steel. 

That small hose is a coolant bypass that allows some of the water to circulate through the engine allowing the engine two to stay evenly tempered between the two parts of the cooling system until the thermostat opens.   It’s a common problem with rotting out when there is not enough maintenance and changing of the coolant in the system.  

Possible solutions are as per Yamaha mechanics: 

Remove the cylinder head, drill out the old broken stem.  Tap the hole with a 3/8” or 1/4” thread tap/die and install a new brass threaded hose stem. Teflon and thread it in  and you should be good to go.   

The second way is to send the head out to a machine shop and they will remove the old stem and press a new one in but finding a machine shop to do that is a specialty item.  

The other option is to find a used or new cylinder  on eBay and install it.  I’ve looked on eBay there are a few.

In my opinion all options suck! 

I have attached a few pics of the cylinder  for you as well as some  brass fittings that will work.  

 

Hope this helps. 

Good luck   

 

 

 

[Coyote]

I had same thing happen to my grizzly 660 and decided I didnt want to pull the head and replace the whole thing., So I drilled out the old nipple and went to tractor supply and bought a small brass threaded air hose nipple, tapped it out  (threaded it). Was all very simple and better than factory. Worked like a champ. 

[Gwbarm]

Good work, great idea. 

[Mech]

Brass and aluminium have a bad habit of corroding badly when they are together with water. The zinc in the brass is the trouble. Silicon bronze is better, or insulating the two materials with something like the thread tape the yamaha mech suggested might work if the tightening doesn't cut through the tape. Those water pipe fittings are also availiable in steel though which will possibly out last anything that sets up an electrolysis reaction as the brass does.

[OzarkPerformance]

I have drilled out several of those and made new ones on the lathe.  I typically use epoxy to isolate the two metals when installing them and haven't had any issues.  

[Gwbarm]

When im doing something like that with water i generally use Anti Seize, but epoxy is better, since you dont want it coming out anyway.

[OzarkPerformance]

Me too if I want it back out.

[Mech]

I use multi purpose Loctite Master Gasket for that, locking nuts and sealing gaskets or gasketless joins..  Absolutely amazing stuff. I highly recommend it.

[Gwbarm]

I havent used loctite , but thats a great idea. Thanks for the tip.

[Mech]

It's the most economical sealer out there, as well as being multi use. It's not as hard as the proper loctite for nuts, but it works on non-citical stuff.

It doesn't make a mess like silicon either and doesn't block pick-up sieves or small holes.. The excess can be wiped off the outsides of cases with a rag and inside the excess just dissolves into the oil without doing any harm to anything. I've even used it, reluctantly, on auto transmissions which have heaps of very sensitive shuttle valves in them, and it doesn't even make them sticky.. which is amazing !

[OzarkPerformance]

That's a great idea