NEW thermostat stuck open?

Igofar · Jan 12, 2017

Glad you got it sorted out with the T-stat.
Sounds like it would be a good idea to lift the tank, check the air filter, and maybe consider cleaning the plastic 5 way tee out, replacing the lines, and doing a TB sync.
My bike shows 55-59 mpg at 80 mph on the freeway, and I always get an average of mid to high forty's.
How many miles on your bike?

gsforster · Jan 12, 2017

I wonder about the ect and its signal. Could be false cold engine signal making the engine run rich

JimGregory · Jan 12, 2017

Igofar said:
Glad you got it sorted out with the T-stat.
Sounds like it would be a good idea to lift the tank, check the air filter, and maybe consider cleaning the plastic 5 way tee out, replacing the lines, and doing a TB sync.
My bike shows 55-59 mpg at 80 mph on the freeway, and I always get an average of mid to high forty's.
How many miles on your bike?

I'm not absolutely convinced I didnt tweak the new Tstat but maybe it's fine.
I do have a new 5 way and some spare hose just waiting for that job. The air filter is brand new. The old one looked fine. The bike has 14,250 miles. I got it last spring with 7500.
I know that I have never seen over low 40's any time ever in the last 7000 miles. I though that was an urban myth.
The bike runs sweet though. Always has and never missed a beat.
Could my staintunes possibly mess with this?

Mellow · Jan 13, 2017

Another thread pointing to a bad ECT
https://www.st-owners.com/forums/showthread.php?129490-2004-ST-THERMOSTAT-Maybe-I-found-something-interesting-not-mentioned-before

Dave.David · Jan 13, 2017

I've only had my ST 1300 for two or three hundred miles and getting around 33 miles per gallon. What is the 5 way and hose ?

Mellow · Jan 13, 2017

Dave.David said:
I've only had my ST 1300 for two or three hundred miles and getting around 33 miles per gallon. What is the 5 way and hose ?

Circled in green, thanks to supersabre for the image

Dave.David · Jan 13, 2017

Mellow said:
Circled in green, thanks to supersabre for the image

That didn't work as well as hoped. Do you know the name of it so I can look it up in the book?

Dave.David · Jan 13, 2017

Dave.David said:
That didn't work as well as hoped. Do you know the name of it so I can look it up in the book?

But in this repost the pic looks good. Thank you

Mellow · Jan 13, 2017

Dave.David said:
That didn't work as well as hoped. Do you know the name of it so I can look it up in the book?

17201-MCJ-003 but, you don't have to replace them, you can just remove and clean them out with a pipe cleaner or the like. They usually collect gunk over time.

JimGregory · Jan 13, 2017

Mellow said:
Another thread pointing to a bad ECT
https://www.st-owners.com/forums/showthread.php?129490-2004-ST-THERMOSTAT-Maybe-I-found-something-interesting-not-mentioned-before

Seems like it was pointing to a bad sensor but turned out to be a bad connection in the wire loom? Not sure too many abbreviations!

Dave.David · Jan 13, 2017

Mellow said:
17201-MCJ-003 but, you don't have to replace them, you can just remove and clean them out with a pipe cleaner or the like. They usually collect gunk over time.

Thank you Mellow. Is this under air box, air box has to come out?

Mellow · Jan 13, 2017

Dave.David said:
Thank you Mellow. Is this under air box, air box has to come out?

yes, but not all that difficult. Plus you get a great view of the throttle bodies and all the connectors to just give you peace of mind that it all looks good.

JimGregory · Jan 13, 2017

Mellow said:
17201-MCJ-003 but, you don't have to replace them, you can just remove and clean them out with a pipe cleaner or the like. They usually collect gunk over time.

if you are placing a parts order like I do every so often with partzilla, it's good to get little inexpensive bit's like the 5 way connector. It doesn't wear out, but it can break from ham fisted home mechanics like myself.
THAT SAID, the most popular reason for bad fuel mileage is the thermostat has gone hinky. Your bike likely could use a coolant flush anyway, so read up on the 374.5 threads on coolant change and thermostat issues. It's not that hard at all and a good initiation to the world of tupperware. And the bleed hole goes UP.. at 12:00 please.

Dave.David · Jan 13, 2017

Mellow said:
yes, but not all that difficult. Plus you get a great view of the throttle bodies and all the connectors to just give you peace of mind that it all looks good.

Now I have next week's project. Thank you much Mellow and this forum.

Mellow · Jan 13, 2017

Dave.David said:
Now I have next week's project. Thank you much Mellow and this forum.

The toughest part of the airbox removal are the funnel screws, sometimes they are in there so tight you strip the heads trying to get them out. Helps to get one of those handheld impact drivers to get them loose the first time.

Here's something Byron encountered and rectified:
https://www.st-owners.com/forums/showthread.php?15358-ST1300-Base-Funnel-Screws-(Air-Box)-Fix

Igofar · Jan 13, 2017

With all due respect, I would NOT start banging around on the plastic snorkel housings with an impact driver, or you risk breaking stuff.
Before you try to remove ANY screws that look like phillips head screws, you need to purchase a set of JIS drivers (mcmaster carr).
All the screws on your bike are Japanese Industrial Standard (google it) not phillips head screws.
You can remove the airbox and snorkel screws easily with the proper JIS driver without risking damage to anything.
I would also suggest getting a small magnet to attach to the shaft so you don't drop any screws down into the black hole :rofl1:

Igofar · Jan 13, 2017

JimGregory, I attempted to email you, but am having problems with my computor. If you pm me a contact number I will call you on the white courtesy phone and chat if you'd like.
Igofar

gsforster · Jan 13, 2017

Igofar said:
I would NOT start banging around on the plastic snorkel housings with an impact driver, or you risk breaking stuff.

+1 could not agree more. The ears on the throttle bodies that those machine screws thread into are tiny, and a downward strike from the handheld impact would certainly bust things. Don't get me wrong - those impact screwdrivers are indispensable tools, but the weak aluminum casting won't take it. Get a set of JIS drivers. They fit a lot of stuff on import cars too.

JimGregory · Jan 14, 2017

I have owned JIS screw drivers for quite some time. One is my personal favorite.
https://c1.staticflickr.com/1/365/31153674244_586a8f485e_z.jpg

Mellow · Jan 14, 2017

Okay don't work yourself up into a riot. At the time, didn't know about JIS screwdrivers and I didn't hit the impact driver with 100 lbs of force LOL! I simply tapped it to loosen the screws and it worked perfectly without damaging anything.

NEW thermostat stuck open?

Igofar

gsforster

JimGregory

Mellow

Joe

Dave.David

Rider

Mellow

Joe

Dave.David

Rider

Dave.David

Rider

Mellow

Joe

JimGregory

Dave.David

Rider

Mellow

Joe

JimGregory

Dave.David

Rider

Mellow

Joe

Igofar

Igofar

gsforster

JimGregory

Mellow

Joe