Starter Valves Sync, Valve Clearances and Fuel Economy

[Dobby]

My 2007 ST1300 now has 46,000 Kms, and I would assume it is time to synchronize the Starter Valves. I couldn’t say whether this service was ever done as I am not the original owner. I have read the procedure and it involves removing quite a bit of parts in order to reach the necessary area. In light of such an involved procedure, I would want to use the opportunity to repair or replace anything that should be done while I have access (Specifically, should I replace the vacuum hoses and the 5-way T?). What else would you fellow owners suggest I do while working on this task?

Last year, I did quite a bit of routine maintenance: New Tires, New Brake Pads, Serviced Calipers, Changed Brake and Clutch Fluid, Changed Oil and Filter, Change Final Drive Oil. Changed Air Filter, New Spark Plugs, New Battery, Flush and Fill Cooling System, Install New Thermostat and O ring. As far as I can tell, she runs spectacularly well and is a joy to ride…..But there is one problem:

Over the last five fill-ups, my mileage has noticeably decreased. I typically got at least 450 kilometers before the last bar began flashing. Now, it seems that I am only getting between 360 and 370 kilometers when the last bar begins to flash. What could cause such a drop in fuel economy? My subsequent research suggests either:

1. A stuck thermostat (is that possible when it was changed only about a year ago?)
2. Brake Drag (this one is hard for me to decipher as I am not sure how freely the wheels are supposed to spin). With a good, robust tug I get two full rotations on the rear wheel. On the front wheel, I get two and three quarters rotations. I have made videos of my front and rear wheel spins but can’t seem to attach them.
3. Clogged 5-way T and/or hoses (which I plan on inspecting while synchronizing the starter valves), and possibly replacing if recommended by the resident experts).
4. Clogged Air Filter (I have recently inspected the Air Filter and it is still in clean/new condition).
5. Tire Pressure (My Tire Pressure is consistent, 42 PSI).

The only other thing I have changed is the addition of a Bike-Quip, Extra Wide Windshield, which is about 2 inches wider on each side. Somehow, I don’t believe the wider windshield could make such a large, 80-90 kms difference. Any suggestions as to what I can do to regain my lost fuel efficiency will be greatly appreciated.

For the Canadians on here, anyone know where in the GTA (Durham Region} I can have the valve clearance checked and serviced if necessary. I am game to do most routine maintenance myself, but doing the valve clearance and possibly installing new shims kinda scare me a bit too much. At least I haven’t seen a video with which I felt comfortable enough to tackle that job. I am not aware of any shop in the general Toronto area that has experience working on the ST1300.


Thanks guys….

 

[jfheath]

Thinking out loud - hang on….
450km is 281 miles with about 45 miles left is the lower tank = 326 miles.
370km is 231 miles +45 = 276 miles per tank.

The lower figure is about what I would get from both of my ST1300s. An A6 and an A9 - fairly consistent over a total of 150,000 miles. 240,000km
My riding was nearly always fully loaded, 2 up and mainly on country Uk roads - lots of ups, down, accelerate and slow down.
On the rare occasions I did a lot of main road riding at a constant 60-70 mph, the range of the tank increased dramatically but rarely to more than a calculated 300 miles per tank - brim full to empty.

Certainly carrying out the starter valve synch makes the engine spin much more freely - a real wow factor, and km/litre goes up.
Valve clearances also help - but you can check the clearances to see if they need changing. You ‘only’ have to lift the cam shaft cover for that - but research that first.
There are things to be wary of - like applying sealant to the half moon part of the rubber gasket; the 3 rubber washer seals for each bolt should be replaced; the difficulty of lining up the long cover bolts with the threaded hole when you can’t see what you are doing…

I wouldn’t trust any garage ….

——-

There is a water drain pipe that runs from the side of the filler neck, through the fuel tank and down to a rubber tube that ends near the gearshift mechanism / oil filter below the sump on the rear left of the engine.

The problem is that fine grit and sand falls with rain and gets thrown up by car tyres from wet roads. That gets stuck in the metal tube inside the fuel tank and you get a permanently wet cluster of sand grit and water. It slowly eats away at the metal tube and eventually, fuel from the tank can seep out through that tube and get deposited on the road. It can also block the metal tube and prevent rain water from escaping so the next time you open the filler cap, it pours into the petrol !

Every now and then I’d blast the line from the rubber hose joint on the left hand side near to the long pivot bolt for the rear of the tank. Cover the filler neck and catch what emerges with a paper towel. It shoots out with a pop. Then clamp the hose and pour in some acf50 and let it sit for a while. Then drain it into a small bottle - the acf50 can be reused for the same job next year.

If that has happened, that would cause a significant drop in your miles/km figures - and probably won’t do your rear tyre grip much good either !

——-

Others may have other points of view. For me, the lower figure is more reasonable, but our riding stiles will be different. But the drop in consumption really begs the question - what else has changed ? The most likely thing would be tyres. Accurate Mileage / speed is dependent on the diameter of the tyres. If you have fitted a larger diameter tyre than what you had before, then the wheel is rotating more slowly and making fewer revs per km . That is going to affect the accuracy of the odometer.

————

The other significant factor is you. The bike is newish to you. It is a massive, very heavy tourer. But when the sun comes out and with a few tanks full of fuel under your throttle hand, you find out what the S in ST stands for. 450 compared with 370 ? That might just mean that you are having 17% more fun than before !

 

[TerryS]

You can test your thermostat with your hand (I promise it won't hurt much). Start the engine from cold and keep a hand on the radiator for a few minutes. A functioning thermostat keeps the coolant in the engine until it is around 78C, then releases that now-hot coolant out to the radiator when the thermostat opens. So the radiator should stay practically cold for a few minutes, then quickly get uncomfortably hot. If that happens, then your thermostat is probably in good health. On the other (unburnt) hand, if the radiator slowly heats from the start, then it is at least jammed part-open and should be investigated further. A jammed thermostat can cause the engine to run colder than intended (which seems unlikely as you are having summer at present) and the FI system will run rich to compernsate.

Your wheel rotations sound pretty normal to me, so I doubt drag is a cause.

You have already checked the air filter, so I would suggest replacing the spark plugs as it sounds as if you are addressing any overdue maintenance.

If you do decide to take the airbox out, it pays to use a JIS screwdriver bit to avoid chewing out stubborn air funnel scews with an ill-fitting phillips-head.

 

[jfheath]

If you do decide to take the airbox out, it pays to use a JIS screwdriver bit to avoid chewing out stubborn air funnel scews with an ill-fitting phillips-head.

+1 on that. Get a set ordered. A Philips or Pozidrive head WILL chew up the screw head, and then you will have a much bigger problem.
Do the rear ones first - they are harder to get at. Put the Jiz driver in to the cross slot vertically. Press down with one hand, turn the handle with the other - maintain the same turning force rather than trying to increase it significantly. It will suddenly yield.

Do Not think - it’s Ok, I’ll give it a go with a Philips. They can’t be that different. Yes they can. The front two screws are ‘held’ in place - lift the air box with them still in there - gently so as not to allow them to drop out, and remove them once the lid is clear. Fit in the same manner with the screws in situ. You’ll see what I mean.

If you must try , then use the tool in the official tool kit, but my experience is that you cannot get enough weight and grip on that if the screws have tightened.
Warming the plastic may help - but you are working near a tank full of of fuel. Emptying and Removing the upper tank gives much more room, but you must replace the short bent hose and string clips. So order them too. The design of that changed around 2008. Make sure you order the part for your model.

 

[Andrew Shadow]

All of the maintenance that you mentioned that you have performed you stated was all done last year. This increase in fuel consumption happened starting five tanks of fuel ago, so I assume that this is all this year. My first question is was there anything that was done, no matter how minor or unrelated that it may seem, immediately or not long before five tanks ago? That would be the first thing to consider and investigate.

I have never used anything other than the Honda OEM windscreen so I don't know how much a larger surface area windscreen affects fuel consumption. Many on here do have bigger windscreens on their ST1300's so maybe they can shed some light on that.

 

[jfheath]

I have experimented with the ‘instant’ mpg read out - which takes readings over a 15 second period. Long Straight road, gentle headwind, with the screen up and with the screen down. Repeated a few times to ensure consistency. I don’t think that I reported it on these pages, nor have I come across any record of it. But to me the readouts showed a noticeable and consistent drop in mpg (actually miles per litre on my uk model) between the 2.

Same gear, level road, screen full up v screen full down. It’s easy enough to carry out your own experiment. I was probably in 3rd gear doing 50mph, as I wanted the engine to be demanding fuel to exaggerate any difference. I was convinced that screen up full made a difference. It didn’t affect how I ride -my screen is a bike-quip with a flip up. I normally ride looking over the top of the screen with the airflow going over the top of my helmet

 

[Dobby]

Thinking out loud - hang on….
450km is 281 miles with about 45 miles left is the lower tank = 326 miles.
370km is 231 miles +45 = 276 miles per tank.

The lower figure is about what I would get from both of my ST1300s. An A6 and an A9 - fairly consistent over a total of 150,000 miles. 240,000km
My riding was nearly always fully loaded, 2 up and mainly on country Uk roads - lots of ups, down, accelerate and slow down.
On the rare occasions I did a lot of main road riding at a constant 60-70 mph, the range of the tank increased dramatically but rarely to more than a calculated 300 miles per tank - brim full to empty.

Certainly carrying out the starter valve synch makes the engine spin much more freely - a real wow factor, and km/litre goes up.
Valve clearances also help - but you can check the clearances to see if they need changing. You ‘only’ have to lift the cam shaft cover for that - but research that first.
There are things to be wary of - like applying sealant to the half moon part of the rubber gasket; the 3 rubber washer seals for each bolt should be replaced; the difficulty of lining up the long cover bolts with the threaded hole when you can’t see what you are doing…

I wouldn’t trust any garage ….

——-

There is a water drain pipe that runs from the side of the filler neck, through the fuel tank and down to a rubber tube that ends near the gearshift mechanism / oil filter below the sump on the rear left of the engine.

The problem is that fine grit and sand falls with rain and gets thrown up by car tyres from wet roads. That gets stuck in the metal tube inside the fuel tank and you get a permanently wet cluster of sand grit and water. It slowly eats away at the metal tube and eventually, fuel from the tank can seep out through that tube and get deposited on the road. It can also block the metal tube and prevent rain water from escaping so the next time you open the filler cap, it pours into the petrol !

Every now and then I’d blast the line from the rubber hose joint on the left hand side near to the long pivot bolt for the rear of the tank. Cover the filler neck and catch what emerges with a paper towel. It shoots out with a pop. Then clamp the hose and pour in some acf50 and let it sit for a while. Then drain it into a small bottle - the acf50 can be reused for the same job next year.

If that has happened, that would cause a significant drop in your miles/km figures - and probably won’t do your rear tyre grip much good either !

——-

Others may have other points of view. For me, the lower figure is more reasonable, but our riding stiles will be different. But the drop in consumption really begs the question - what else has changed ? The most likely thing would be tyres. Accurate Mileage / speed is dependent on the diameter of the tyres. If you have fitted a larger diameter tyre than what you had before, then the wheel is rotating more slowly and making fewer revs per km . That is going to affect the accuracy of the odometer.

————

The other significant factor is you. The bike is newish to you. It is a massive, very heavy tourer. But when the sun comes out and with a few tanks full of fuel under your throttle hand, you find out what the S in ST stands for. 450 compared with 370 ? That might just mean that you are having 17% more fun than before !

Thank you, John, for your thoughtful response. I always ride solo, no luggage of any kind, windshield positioned so that I look over it and not throught it, 120 kmh or less when on open freeway. I did take it up to about 160 kmh for a few seconds just to see what it felt like; it was exhilerating and acutally felt smooth. However, most of my riding is on the smaller back roads where I travel 80-90 kmh. and I am ususally very gentle on the throttle. Perhaps that is why I (used to) get higher mileage per tank. I started logging my mileage from the very first time I acquired the Bike, so the pattern I observed over the last five fill-ups was very easy to notice.

Following your advice, I just completed blowing out that rubber drain tube and pouring in some AC50. It did not seem to be clogged but I am glad I did the procedure.

I definitely plan on doing the Starter Valve Sync as soon as my Carb Tune Pro 4 arrives. There is a great Article on this Site with very clear pictures so I feel confident about this one. However, I have not seen any Article or Videos about checking and adjusting the Valve Clearance, hence my apprehension. From what I have read, there aren't many mechanics with a lot of knowledge and experience on the STs. So, yeah, I could see where finding/trusting a suitable mechanic could be problematic

As far as changes go, the only addition that was out of spec was my new Bike-Quip windshield which is only 2 inches wider on each side. I replaced my Tires with Michelin Road 6s, but they were the original sizes.

 

[Dobby]

Thanks for the tip on the JIS Screwdrivers. Just ordered a set on Amazon

 

[Dobby]

You can test your thermostat with your hand (I promise it won't hurt much). Start the engine from cold and keep a hand on the radiator for a few minutes. A functioning thermostat keeps the coolant in the engine until it is around 78C, then releases that now-hot coolant out to the radiator when the thermostat opens. So the radiator should stay practically cold for a few minutes, then quickly get uncomfortably hot. If that happens, then your thermostat is probably in good health. On the other (unburnt) hand, if the radiator slowly heats from the start, then it is at least jammed part-open and should be investigated further. A jammed thermostat can cause the engine to run colder than intended (which seems unlikely as you are having summer at present) and the FI system will run rich to compernsate.

Your wheel rotations sound pretty normal to me, so I doubt drag is a cause.

You have already checked the air filter, so I would suggest replacing the spark plugs as it sounds as if you are addressing any overdue maintenance.

If you do decide to take the airbox out, it pays to use a JIS screwdriver bit to avoid chewing out stubborn air funnel scews with an ill-fitting phillips-head.

Thanks, Terry, I will definitely try the "burnt hands technique" to determine whether my thermostat is stuck in a particular position.

 

[jfheath]

@Dobby - pm sent with some notes that I took a long time ago.

 

[CruSTy]

I’ve had 3 different wind screens. Some with tuning brackets. They caused as much as a 3-4 mpg drag difference on the fuel consumption. I suspect your wider windscreen is at least partly to blame.

 

[Dobby]

I tried to upload a short video of my wheel spin but was unable to do so. I then posted the videos on facebook ST forum. Based on the feedback, it would seem that I have a warped rear rotor. Not sure about the front Rotors. I get two full roatations on the rear with intermitent "friction: sound. The front wheel gets two and three quarters rotations with a more consistent sound. I hope I am not breaking any rules but here is a link to the videos. Perhaps the experts could have a look/listen and let me know whether there's anything wrong with my breaks.

https://www.facebook.com/1417187743/videos/pcb.1355489859359486/1735778097732945

https://www.facebook.com/1417187743/videos/pcb.1355489859359486/1031220259662161

 

[sTaylor]

Thinking out loud - hang on….
450km is 281 miles with about 45 miles left is the lower tank = 326 miles.
370km is 231 miles +45 = 276 miles per tank.

The lower figure is about what I would get from both of my ST1300s. An A6 and an A9 - fairly consistent over a total of 150,000 miles. 240,000km
My riding was nearly always fully loaded, 2 up and mainly on country Uk roads - lots of ups, down, accelerate and slow down.
On the rare occasions I did a lot of main road riding at a constant 60-70 mph, the range of the tank increased dramatically but rarely to more than a calculated 300 miles per tank - brim full to empty.

Certainly carrying out the starter valve synch makes the engine spin much more freely - a real wow factor, and km/litre goes up.
Valve clearances also help - but you can check the clearances to see if they need changing. You ‘only’ have to lift the cam shaft cover for that - but research that first.
There are things to be wary of - like applying sealant to the half moon part of the rubber gasket; the 3 rubber washer seals for each bolt should be replaced; the difficulty of lining up the long cover bolts with the threaded hole when you can’t see what you are doing…

I wouldn’t trust any garage ….

——-

There is a water drain pipe that runs from the side of the filler neck, through the fuel tank and down to a rubber tube that ends near the gearshift mechanism / oil filter below the sump on the rear left of the engine.

The problem is that fine grit and sand falls with rain and gets thrown up by car tyres from wet roads. That gets stuck in the metal tube inside the fuel tank and you get a permanently wet cluster of sand grit and water. It slowly eats away at the metal tube and eventually, fuel from the tank can seep out through that tube and get deposited on the road. It can also block the metal tube and prevent rain water from escaping so the next time you open the filler cap, it pours into the petrol !

Every now and then I’d blast the line from the rubber hose joint on the left hand side near to the long pivot bolt for the rear of the tank. Cover the filler neck and catch what emerges with a paper towel. It shoots out with a pop. Then clamp the hose and pour in some acf50 and let it sit for a while. Then drain it into a small bottle - the acf50 can be reused for the same job next year.

If that has happened, that would cause a significant drop in your miles/km figures - and probably won’t do your rear tyre grip much good either !

——-

Others may have other points of view. For me, the lower figure is more reasonable, but our riding stiles will be different. But the drop in consumption really begs the question - what else has changed ? The most likely thing would be tyres. Accurate Mileage / speed is dependent on the diameter of the tyres. If you have fitted a larger diameter tyre than what you had before, then the wheel is rotating more slowly and making fewer revs per km . That is going to affect the accuracy of the odometer.

————

The other significant factor is you. The bike is newish to you. It is a massive, very heavy tourer. But when the sun comes out and with a few tanks full of fuel under your throttle hand, you find out what the S in ST stands for. 450 compared with 370 ? That might just mean that you are having 17% more fun than before !

“Every now and then I’d blast the line from the rubber hose joint on the left hand side near to the long pivot bolt for the rear of the tank.”

… Is this the solo hose forward front of the (2) rearward hoses that are parked together?
Thanks-

 

[etalors]

Over the last five fill-ups, my mileage has noticeably decreased. I typically got at least 450 kilometers before the last bar began flashing. Now, it seems that I am only getting between 360 and 370 kilometers when the last bar begins to flash. What could cause such a drop in fuel economy? My subsequent research suggests either:

1. 450 Kilometers before the flashing bar is actually quite good. I am assuming it is on the HWY at a constant speed. Was this achieved with the gas tank filled all the way to the top or up to the neckline as described in the manual (which would be a little less fuel)

2. 360-370 Kilometers: Are you filling up the same way and riding the same way as when getting 450 Km.

3. A stuck T stat will not cause the gas mileage to go down. I had a stuck T stat and got almost normal mileage.

 

[Grand Rouge]

Dobby..... caught yer face book vids. Rotors etc. are fine. Too many folks ready to spend your money on useless repair / parts replacement. Rotor run out....normal and a desirable situation. No indication of dragging.. Additionally, the friction surface is mated to the rotor 'hub' via buttons...Friction surface not fixed in place.

I have 2 ST 1300's. Both 2005. One has the VStream shield. The other a PUIG. I have switched screens between these machines. The VStream robs just under 2MPG on either machine. Additionally, on both, windscreen raised / lowered....as much as 1 mpg. Not a tightly controlled test here...But...mileage computed at the gas pump...and over 1,500 miles each machine. Lots of freeway riding...70 to 80 mph. 43 to 46 MPG.

Just my ten cents worth...Cdn.

 

[Dobby]

1. 450 Kilometers before the flashing bar is actually quite good. I am assuming it is on the HWY at a constant speed. Was this achieved with the gas tank filled all the way to the top or up to the neckline as described in the manual (which would be a little less fuel)

2. 360-370 Kilometers: Are you filling up the same way and riding the same way as when getting 450 Km.

3. A stuck T stat will not cause the gas mileage to go down. I had a stuck T stat and got almost normal mileage.

On the rare occasion that I go on the major highways, I would stay between 110-120 kmh, never exceeding 120. I always fill up with the bike on the side stand and stop right at the neckline as noted in the owners manual. I also use the 93 Octane at my local ESSO. Most of my riding is done on back roads where I stay in the 80-90 kmh range. I suppose my riding habits are partially dictated by my wife who almost always rides with me on her Honda Rebel. She hates the Highways and prefers to take the smaller side Roads. It's good to hear that a stuck Thermostat might not have a huge impact on mileage.

 

[Dobby]

Dobby..... caught yer face book vids. Rotors etc. are fine. Too many folks ready to spend your money on useless repair / parts replacement. Rotor run out....normal and a desirable situation. No indication of dragging.. Additionally, the friction surface is mated to the rotor 'hub' via buttons...Friction surface not fixed in place.

I have 2 ST 1300's. Both 2005. One has the VStream shield. The other a PUIG. I have switched screens between these machines. The VStream robs just under 2MPG on either machine. Additionally, on both, windscreen raised / lowered....as much as 1 mpg. Not a tightly controlled test here...But...mileage computed at the gas pump...and over 1,500 miles each machine. Lots of freeway riding...70 to 80 mph. 43 to 46 MPG.

Just my ten cents worth...Cdn.

Thanks, Grand Rouge, that's very encouraging about the Rotors!!. I was just looking up the prices of Rotors and it made me mutter a few choice "words" to myself. I am not sure I understand the whole friction surface and buttons thingy but I am nonetheless very happy about it. 43 to 46 MPG at 70-80 MPH sounds very good to me, I haven't really calculated my MPG as I was going by total distance from full tank (neck of tank) to flashing bar. Either way, I doubt my 370 KMs per tank is equivalent to 43 to 46 MPG, and I want my lost 80 kms (average per tank) back.

With regard to windshields, I believe your V-Stream is wider than my Bike-Quip Extra wide.

One question: Is it normal to have areas on the rotors that exhibit more friction than others? When I turn the wheel slowly, I could tell exactly where there is more friction and where there is minimal.

 

[Grand Rouge]

Dobby.... I did not clarify my thought / description re rotors.. That is on me. Front rotors are two piece units.

Rear is one piece affair. Was hearing the swooshing sounds front and rear...again...normal.

Lower fuel mileage.....do not have any real thoughts....other than...

When I ride wonderful roads with sweepers and elevation changes and some twisties too...on occasion... I have had fill ups along the exciting riding route with calculated mileage as low as the mid 30's. Darn grin factor anyway.

 

[etalors]

I always fill up with the bike on the side stand and stop right at the neckline as noted in the owners manual. I also use the 93 Octane at my local ESSO. Most of my riding is done on back roads where I stay in the 80-90 kmh range. I suppose my riding habits are partially dictated by my wife who almost always rides with me on her Honda Rebel. She hates the Highways and prefers to take the smaller side Roads. It's good to hear that a stuck Thermostat might not have a huge impact on mileage.

Filling up on the side stand, means a little bit less fuel than if you were on the Center Stand, filling up to the same mark. However, if your riding is at an average speed of 85 km/hr or 51 mph and if in the 5th gear. You should get some great gas mileage. 85 km/hr is about the sweet spot for a rebel 250. That engine loves 50 mph. I had a nighthawk 250, so that is how I know. There does not seem to be anything wrong with your bike.

Here is my 0.1c. Fill up your tank the way you normally do and go on a 450 km solo trip (225 km each way), possibly on the highway (to eliminate variables of stop and go and variation in speeds) and see where the flashing bar comes on. Maintain an indicated speed of 115 km/hr. You should be able to get close to 450 km.