Thermostat replacement

[dduelin]

I’m glad you undertook the job and saw it to completion. Happy miles to you.

 

[ChampCar]

In this photo you can see how the old one was stuck in the open position. Have put about 75 miles on the bike since. It’s running better and the temp gauge is staying where it should.

 

[ForwardUntoDawn]

In this photo you can see how the old one was stuck in the open position. Have put about 75 miles on the bike since. It’s running better and the temp gauge is staying where it should.

what's the part number for the thermostat? Did you change just the thermostat alone or the housing, as well?

 

[dduelin]

what's the part number for the thermostat? Did you change just the thermostat alone or the housing, as well?

The Honda P/N is 19300-MBT-003. Unless severely corroded the thermostat housing does not usually require replacement. The O ring sealing the housing should be replaced. P/N 91361-MCS-A10.

 

[Larry Fine]

The O ring sealing the housing should be replaced. P/N 91361-MCS-A10.

One should come with the T-stat. It doesn't, but it should. Car T-stats include them.

 

[dduelin]

One should come with the T-stat. It doesn't, but it should. Car T-stats include them.

Some do and some don’t. It’s not universal but housings sealed with rubber O-rings don’t include the O-ring as it is often reusable. Lots of Toyota and Honda thermostats don’t include the O-ring.

 

[Oldbikefixr]

The Honda P/N is 19300-MBT-003. Unless severely corroded the thermostat housing does not usually require replacement. The O ring sealing the housing should be replaced. P/N 91361-MCS-A10.

Back when I rebuilt my 1991, I found this condition on the housing. This bike had sat up in the PO's garage for 20 years. Almost didn't see it at first, 'cause I just cleaned off the crust with a steel wool pad. It looked acceptable but for brownish discoloration so I ran it thru my bead blaster to remove it. It was just compacted corrosion and this is what I found. The little dark dot is a hole that penetrates the fitting. The land on the fitting was never going to seal again...found similar on the two larger hose fittings. The first photos didn't do it justice so I sprayed it with silver paint and it all jumped right out in the photos. Thought about fixing it with epoxy/JB weld for a few seconds and ordered a new one.

 

[Rob20111]

Found mine stuck open too.
Should be closed when cold.
Only 10k miles on the clock.
I only checked it because I was changing out a leaky O-ring. Glad I did.
Runs better, warms up quicker, and mpg improved.

 

[ForwardUntoDawn]

The Honda P/N is 19300-MBT-003. Unless severely corroded the thermostat housing does not usually require replacement. The O ring sealing the housing should be replaced. P/N 91361-MCS-A10.

Thank you, very much! Happy holidays!

 

[SupraSabre]

Found mine stuck open too.
Should be closed when cold.
Only 10k miles on the clock.
I only checked it because I was changing out a leaky O-ring. Glad I did.
Runs better, warms up quicker, and mpg improved.

Yeah, the stuck Thermostats were a major issue for the 03 -05 or 6s.

I had one too that I had to fix. I wasn't about to take it into the stealership and let them have for a week or two.

And I even made a TechSTOC out of it.