Re: ST1300-1st Significant Service: Coolant, Thermostat, Starter Valve Synch, & Other
Fast forward to March, 2011....
Yeah, this thread has morphed into more than just a report on it's 1st service--it's more like "my bike's service history" LOL.
My '04 dribbled quite a bit of coolant on the ground for a few minutes while in Hutchinson KS on March 28. The temperature at the time was about 27?F. (Thanks Follow for pointing out the leak!) The coolant leak surprised me as I normally see a few drips on cold mornings like that from the ever-leaky hose/connections under the throttle body. After the bike ran for a few minutes and the engine speed dropped to normal idle, the fast dripping tapered off and stopped. For the rest of that day it didn't seem to drip much, but it dribbled again the next morning (cold again). Each morning it dribbled enough coolant to cause a 6"-8" puddle under the bike--perhaps about a half cup ended up on the ground each morning because the overflow bottle was only about a cup low once I got home.
I was thinking the water pump seal was failing, or perhaps a hose to the wax starter valve was damaged enough to leak when the coolant flow was in bypass mode (thermostat closed).
The bike was also due for other servicing although I'd planned to delay the servicing after getting back from Moonshine. But that new behavior of spewing coolant on cold starts required attention so I pulled the bike apart when I got home and had to give up riding to Moonshine this year.
I did the following servicing from April 2, 2011 to April 7, 2011, the bike having 34,078 miles on the odometer at the time.
Coolant Leak Investigation
As documented earlier in this thread, I had gone after coolant leaks a couple times in the past. Each time I was finding the hose connections slowly leaking as if the hose clamps were loose, so I'd tighten the clamps a bit more. But that proved only a temporary fix until the next winter had come and gone.
I pulled all the tupperware and removed the tank and air filter housing. But before I dismantled the coolant system, I borrowed NoBull's Ridgid SeeSnake, worked it in behind the thermostat, and started the bike. Within seconds a pretty fast drip was visible at the right cylinder bank 'water joint', where the hose connects to return coolant to the thermostat housing. I spotted no other leaks at that time, and I was relieved that the problem wasn't bigger. No coolant is draining from the water pump seal hole.
I had read for a couple years in other threads here where the coolant leaking problem was solved by replacing the stock hose clamps with constant tension clamps**, so I'd prepared to do the same and had the constant tension clamps on hand. I chose to do the clamp replacements from the front with the radiator and thermostat housing removed, rather than removing the throttle bodies that others have done. Doing the work from the front worked pretty well--it seemed easier than removing the throttle body assembly to me.
**Constant tension hose clamps:
https://www.st-owners.com/forums/threads/st1300-solving-the-coolant-leak-problem-for-good.165403/
Clamp sizes
https://www.st-owners.com/forums/threads/coolant-hose-clamp-sizes.156687/#post-1993326
It turns out that
both the left and right cylinder bank coolant return hoses were leaking.
Look what was in the left cylinder bank coolant return hose!
That would easily jam a thermostat, hopefully not closed!
One point about these constant tension clamps: these things are
huge. If you do the same job, you'll want to think through how you'll orient each one and ensure you can both reach them to tighten them and also not get in the way of other parts that you'll reinstall, and also so that you can access the right cylinder bank cam chain tensioner release. I forgot about that last little point until I was doing valve shim changes the next day.
While the clamps are labeled 'constant tension', they're not constant given their design. They're much closer to constant tension than the stock clamps, so that's definitely a plus. But what I think is just as (or more?) likely beneficial is that they cover about twice the area of hose than the stock clamps. As such there is more uniform pressure over a larger area and the hoses aren't able to squeeze out from under the clamp (my opinion). Regardless of the reasons, I'm hoping that the leak problem is fixed for good. Here are a couple pics of the new clamps in place, utilizing the original hoses (I didn't have new hoses on hand or I would have replaced them).
While some folks replaced the original hose clamp on the front thermostat housing (upper right in the picture below) with a constant tension clamp of the same size as used in the above pictures, this hose is larger and I couldn't get satisfied with the fit of the constant tension hose clamp on it. A larger diameter constant tension hose clamp is warranted IMO. And that connection has never leaked so I took my chances and put the OEM hose clamp back in place. I'd like to have the larger size hose clamp, or perhaps a simpler spring hose clamp of proper diameter on hand for next service.
I finished putting the cooling system back together, ran the SeeSnake back in, and started it up. I was pretty tickled to find no leaks (and 1700 miles later it still isn't leaking).
Valve Checks
The two valve clearances that were at limits at last check (17k mi) were out of spec this time (34k mi). And I found a couple other clearances at spec limits so I decided to change them also. So I had to pull all 4 cams. Yuk. While putting in the constant tension hose clamps a day prior, I saw that cam chain tension release for the right cylinder bank next to the coolant hoses and thought 'that will be a challenge to access tomorrow during the valve checks' ... yep, it was. So I had to reorient one clamp from above (the one on the coolant return from the right head into the thermostat housing) to minimize interference.
I used a 'grabber' to remove and reinstall the cam chain tensioner cover bolt, it worked great. Here's a pic of me putting the bolt/washer back in place:
It took most of one day to do the valve clearances by myself, completing one side before opening the other. Below is how left bank and then right bank were oriented before disassembly, and how I kept the parts organized as I pulled everything. Since I had to remove the cams, I measured all shims and wrote the numbers down on the shop paper towels using a sharpie--numbers in magenta were the original shim thicknesses and numbers in teal were the replacement shim thicknesses. The pictures served as my documentation until later when I could get to a computer to save the information.
Left cylinder bank:
Right cylinder bank:
When I put each cylinder bank back together and rechecked clearances, all were nicely in spec.
Spark Plugs
As they've only got 17k miles on them, I pulled them and checked for atypical signs. All were matching, were good color with good electrode, ceramic, and tip condition. So I put them back in. Here's a sample:
Lubed The Shifter Linkage
There are two small ball joints on each end of a tie rod, each ball joint covered with a rubber 'dust cover'. Of the two, the only one that I could easily get to is the low-right one, just forward of the center stand. That specific ball joint would be the one that has the highest chance of getting damage from road debris. I found the boot in good condition, but the grease inside was pretty gritty and runny. I cleaned it up, putting some fresh grease in place and slid the boot back over. The other ball joint is up high, well protected from any debris, so I left it alone.
Brake Pads
I'm still using the factory-installed brake pads. The measurements of the remaining pads thicknesses for the front 4 pads, left to right were: 3.5, 3.1, 3.5 & 2.0 mm. The new front pads I have on the shelf have 4.0 mm of material on them.
The rear 2 pads, left to right, measured 2.7 & 3.2 mm--the new rear pads on the shelf have 5.5 mm on them. I thought they'd be needing replacement soon, but to my surprise there's at least 40% remaining on the most worn front and rear pad.
Hydraulic Clutch Fluid
The hydraulic fluid darkens quicker than the brake fluid and it's an easy change out, so that was done again. I decided the brake fluid can wait for another day this year, or a brake pad change, whichever comes first. I don't use a mighty-vac, but the old slow pumping method while manning the bleeder with a wrench.
Electric Windshield
I opened up the windshield cowling to clean and lubricate the windshield slides. Last time after cleaning a lot of dark sticky grit off the slides, I used DuPont Teflon spray. This time I found the slides were surprisingly clean and easy gliding. So I gave another dose of Teflon spray to the slides after a slight cleanup. While in there, I opened up the motor/gear mechanism and found it to appear in good condition, so I sprayed in a little low viscosity lithium grease as I ran it up and down a number of times.
The upper fairing deflector set has adhesive on it that joins both the windscreen cowl and the panel that surrounds the instrument cluster. Every time I access the windshield slides, that upper fairing deflector adhesive has to be replaced. And the topmost removable rivet, which is supplied with the fairing extenders to join the fairing extenders, the upper cowl, and the windscreen cowl has never fit well. I replaced it with a standard Honda low profile 'splash clip' (see red arrow in picture). While I like the looks of that fairing extender, it sure could have been designed better IMO,
Warm Weather Surging
I still haven't figured out the source of this issue, but when the bike becomes heat soaked, such as after sitting for ~10 minutes, especially at high altitudes, it surges very abruptly at low RPMs and hammers the drivetrain. The problem appeared with no warning several summers ago, months after any service. In trying to diagnose the problem, I've replaced the MAP sensor, replaced the fuel pressure regulator, checked all vacuum lines and electrical connections, and replaced the fuel filter. But it still has this high temperature surging.
So continuing to work on this, I changed out the fuel pump to newer used one I bought from a parted out bike. A couple years ago I put the stock FPR back in place to ensure it wasn't a faulty FPR, and since that had no effect on the surging, I put the TurboTom FPR back into the bike to dampen some of the ST's notorious throttle burst. I also disconnected, wiped, and used dielectric grease on all the connections (including coil connections) that I could access on the bike. I also pulled all the vacuum lines and the 5-way tee... all were super-clean inside with no debris.
I rode through KS & OK a couple days ago where the temps were upper 80's, and did not have any hints of surging. But when I got to higher altitudes on my return trip yesterday, even with cool air temperature, the bike started showing some signs of the problem following riding breaks. Bummer, its not over yet.
At this point, about all that is left is the IAT (I have a spare) and the coils.
Starter Valve / Throttle Body Synch
With the valve shim changes, the idling vacuum changes a bit. So I hooked up my Morgan Carbtune and found slight adjustments were necessary. The vacuum as found is shown below, cylinders 1 to 4 left to right, respectively. When that balance is achieved, the idle RPMs picked up nicely. Ah, it idles smoother now!
Upper-Lower Fuel Tank Hose
A prior one I bought was about an inch too short. I bought
another new one, and it is better but was still ~1/4" shorter than the original! the shorter the hose, the higher the likelihood of it being damaged on tank lifting. Why is Honda shortening it?!
Other Stuff Done
--lubed the wear points on the side & center stands
--checked rear drive oil
--major cleanup on reassembly as I hadn't cleaned it following the snowy return ride from Hutchinson
I put about 30 hours into the above work. I tend to take my time, but hey the price is right and I know the work was done right!
Ready to ride...I left the next morning for a 2-day 1675mile ride.
