Thermostat and throttle body

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I'm in the process of winter maintenance on my 04 1300 and was needing input on the thermostat change. Mine has been doing the 2 bar 3 bar thing under 65 degrees. I've read through a lot of posts but haven't found an answer to this question. I'm going to change the upper and lower radiator hoses and was thinking about changing the 2 water hoses that come out of the thermostat housing that hook up to the water inlets on top of the engine under the throttle bodies. It looks like it is next to impossible to get to these connections without removing the throttle bodies. Has anybody had these two hoses fail or changed them?

Secrets or regrets on throttle body removal would be much appreciated. Should a stat change be my only concern?

Reason is, when I raised the fuel tank, the connector hose split and drained the last bit of gas out on the floor. Old, stiff hoses.

Thanks
 

SupraSabre

48 Years of SoCal Lane Splitting/Commuting-Retired
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I would say it's time to replace all your coolant hoses and the thermostat.

Try this thread: Some-People-Just-Don-t-Know-When-to-Quit!

#46 for some pictures I took while replacing the ones on my 2004#2.

I'm currently in the process of replacing all of the hoses on my 2010, due to having to remove the throttlebody to replace that wax fuel device.

There is also this thread of my son replacing his.
replacing-all-hoses-and-clamps

Two things I tried on the '04s, that I won't be repeating with the 2010.

1. Don't use Silicon hoses. They slip off too easily
2. Don't use the thermoplastic clamps on the smaller connections. They don't go small enough. Use NAPA 1/4 - 5/16 high presser hose clamps.

To replace the two hoses that go to the oil cooler, The only way I could do that was to drop the oil cooler (where oil filter attaches) with hoses still attached, attach new hoses when you pull them off the oil cooler, then attach the new hoses to the old hoses and pull them up. be careful how you attach them and when you pull them up and don't forget to attach the new hoses to the oil cooler.
 
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cornSTalk
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Thanks for the reply SupraSabre.

I decided earlier to go ahead and replace all of the coolant hoses. The throttle bodies weren't as difficult to remove as I thought they might be. They were pretty snug so here's how I did it. I got my car engine hoist with a small diameter piece of nylon twine and wrapped it around one side of the bodies being careful not to get any fuel lines or linkages (this sure looked like overkill!). I then raised the hoist just enough to put a small amount of lift pressure on the throttle bodies. As I worked to loosen the isolators from the bodies they popped up. Repeated for the other side.

Just as I suspected the thermostat was stuck open 1/4 inch.

The left water inlet aluminum hose fitting was the one that was leaking. I removed both left and right side water inlets to replace O-rings. I then polished all the hose barbs that are aluminum (water inlets and thermostat housing) with 150 grit emery cloth to remove all corrosion and casting molds.

I'm still not sure which hose clamps I'm going to use. I read the entire thread "solving coolant leaks for good". I think that I will coat the hose barb that are aluminum with an epoxy or sealant before installing hoses. Will probably make hose removal more difficult but should eliminate any chances for leaks.

After valve clearance check should head cover gaskets be replaced? They are attached really well to the covers. Gasket sealant?


Head cover gaskets are on order just in case as are all the hoses and other parts that I need. Hopefully Partzilla will get them here by next week.
 

SupraSabre

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I would replace the head cover gaskets. The only sealant you should use on them will be at the cutouts for the cams. There should be some tech articles that cover those. Also one thing you HAVE TO DO, use a torque wrench with the correct torque on all the bolts. This is really important so you won't have leaks at the thermostat and the water inlets.

Glad you got the throttle bodies off. I remove two of the brace bolts rear right, then pry up on the throttlebody. Seems to pop them up nicely. I then use plumber's grease on the insulators so the throttlebody slips back on easly.
 
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I would replace the head cover gaskets. The only sealant you should use on them will be at the cutouts for the cams. There should be some tech articles that cover those. Also one thing you HAVE TO DO, use a torque wrench with the correct torque on all the bolts. This is really important so you won't have leaks at the thermostat and the water inlets.
Personally, I would be a little hesitant about replacing the head cover gaskets, primarily due to cost ($36+ for each from Ron Ayers). If the existing gaskets look and feel nearly as good as new replacement gaskets and they haven't been reused many times, I would take my chances on reusing them. They are designed to be reused as long as they remain undamaged during removal and installation. If either (or both) of them leaks after reassembly, replacing them will not be that big a deal, additional cost would be just the time it would take, which can be minimized by thoroughly checking for leaks before reinstalling the Tupperware.

+1 on correct torque on all the bolts. Besides the ones mentioned, the three bolts that secure each head cover must really be torqued with care. These bolts are a little fragile, and will twist off very easily if even slightly over-torqued, partly because the compression of the gasket is fixed by the bolt shoulders bottoming out against the cylinder heads when the bolts are installed. A major design flaw by Honda (IMHO anyway) makes it tricky to get the threads on these bolts started properly when installing the head covers because it's difficult to "find" the threaded holes in the cylinder heads.
 
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SupraSabre

48 Years of SoCal Lane Splitting/Commuting-Retired
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Personally, I would be a little hesitant about replacing the head cover gaskets, primarily due to cost ($36+ for each from Ron Ayers). If the existing gaskets look and feel nearly as good as new replacement gaskets and they haven't been reused many times, I would take my chances on reusing them. They are designed to be reused as long as they remain undamaged during removal and installation. If either (or both) of them leaks after reassembly, replacing them will not be that big a deal, additional cost would be just the time it would take, which can be minimized by thoroughly checking for leaks before reinstalling the Tupperware.

+1 on correct torque on all the bolts. Besides the ones mentioned, the three bolts that secure each head cover must really be torqued with care. These bolts are a little fragile, and will twist off very easily if even slightly over-torqued, partly because the compression of the gasket is fixed by the bolt shoulders bottoming out against the cylinder heads when the bolts are installed. A major design flaw by Honda (IMHO anyway) makes it tricky to get the threads on these bolts started properly when installing the head covers because it's difficult to "find" the threaded holes in the cylinder heads.
Do as you wish, but I've seen a number of the head cover gaskets start leaking around the sparkplug area and you have oil seeping out along the head gaskets (there is a little drain slot between the sparkplug area and the headgaskets). But replacing them is up to you...on a 12 year old bike, I would replace them!
 
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