700GS RUNNING ROUGH

My 2013 700GS has 10000 miles on the clock and has been running fine. Last week I did 1600 miles riding up to Scotland and touring the NW500. Performance was perfect. Yesterday I had rode about 60 miles everything perfect again.

But my problems started after getting caught in a grid locked traffic jam that took me a good half hour to cover less than a mile. I filtered when I could but for the best part of the half hour I was sitting in 26 degree heat I did switch the bike off on occasions but the cooling electric fan did come on a few times. Once I was through the jam the bike was ok but when I stopped at a set of lights about a mile from the jam, the engine cut out. After a couple of turns it finally started. But from them on when accelerating through the gears it kept missing and then firing up again. It also cut out completely a couple of times in slow traffic.

I managed to nurse the bike home (40 miles) by gently accelerating through the gears and slipping the clutch. Every now and then it would cut out and then fire itself back up. On one stage of the journey I had an open motorway so I took the bike up to 80 and it ran fine. I even slowed down and opened up the throttle in top gear to see if it would misfire and it pulled perfectly. However as soon as I got into traffic again after a while the misfire symptoms returned. It also ticks over nicely and does not misfire when revved with no load.
So it seems that the fault only comes in low gears when accelerating up in relatively slow moving traffic and the symptoms only started after my gridlock.
Can anybody help me on this one please?
Thanks

Could it be be vapour locking in the fuel system due to the unseasonal ( for UK) temps. Easy test just pop the fuel lid and vent the tank.

Worth trying as its a no cost option.

Steve

Thanks for your suggestion Steve. Iwill try it out today I was below half a tank full so I will go fr a run and fill up. Hope it works as it will be much better than spanners ad head scratching��

Sounds like the idle actuation control valve...I found this very longwinded write up about it:

http://f800riders.org/forum/showthread.php/50935-Idle-Control-Idle-Actuator-Air-Bleed-Circuit

I am pretty sure you can get to the valve without removing any body work. Unplug, remove it and clean it. Perform a reset and you should (hopefully) be sorted.

also possible fuel pump failing/overheating

Well I opened the fuel filler cap and then started the bike this morning. Started first time and ran well. Took the bike for a run through some stop start traffic and then through open roads. Stopped the bike and let it run untill the cooling fan operated. The bike didn't miss a beat. By now my low fuel light was on and engine still runs ok.

So the 'problem' seems to have been what Steve suggested (vapour block) and thank you Steve. I have filled the tank with some Shell premium fuel and been for another run and all is running perfectly.

Whilst I am happy for my bike to be running perfectly again I am still curious as to how/why a vapour block should build up? I know it was hot yesterday (26 degrees) but this is not really hot when compared to the type of heat that these bikes operate in other really hot countries.
By the way no warning lights came on throughout the period that the bike was playing up.

Like I say I am glad it's ok now but can't help but wonder if it is a problem waiting to come back. Anyone else ever had this happen in hot weather and grid locked traffic?

Glad you had a result, however You will have a nagging doubt until you get some substantial miles under your belt. Its a pity no lights came on as you could have asked someone with a GS911 to "read " the fault code.

I have to say I have never had it and only took a punt because in the early days of F800 /650's there was a breather mod this was back in 2008.

Anyway enjoy and by the way well done on the NC500. I did it in May this year, great road for a middleweight trailie as you never really get too much speed up. I loved it on my F650 twin.

Steve

I had the same back in July coming home from a trip to the west country. Filled up at the services at the bottom of the M3 and went for the M25 to get to Essex.
Part way round the 25 the bike; a 2008 F800GS; hesitated and then cut just like it was running out, despite having almost half a tank still. After a couple of seconds; of abject terror on my part as I was in the middle lane with a damn great lorry behind me; it fired up again. Ran fine for a couple of miles and then did it again.
As the temperature was about 28C, which is exactly 82F, I knew what it was - vapour lock in the fuel tank.
Just to explain: this is when the fuel tank heats up inside due to the air temperature. So the pressure inside the tank becomes greater than that outside. So instead of drawing air into the tank it is trying to push air out. Thus stopping the fuel flow from the tank to the engine.
Simply stopping and opening the fuel cap solves the problem. My 1150 did this a couple of times and I could vent that on the move (clutch in, key out of ignition, open-close tank, key back in ignition, switch on, rev and go) but its not possible on the 800.
The bike did this several times on the M25 that day and I was convinced I was going to get creamed by a truck. Some bright spark has decided that a hard-shoulder is a waste of space so I was trying to get the bike sorted in the six inches between the nearside lane and the edge of the road - with cars and lorries coming by at 70 plus two inches off the right pannier. Not nice.

i don't undersdtand this vapour- lock thing. Surely the fuel pump is submersed and immune from vapour-lock. besides, a positive air pressure in the tank would surely aid the fuel flow rather than hinder it. Isn't there a breather pipe to prevent this vapour lock in the first place?

steve hughes said:

Glad you had a result, however You will have a nagging doubt until you get some substantial miles under your belt. Its a pity no lights came on as you could have asked someone with a GS911 to "read " the fault code.

I have to say I have never had it and only took a punt because in the early days of F800 /650's there was a breather mod this was back in 2008.

Anyway enjoy and by the way well done on the NC500. I did it in May this year, great road for a middleweight trailie as you never really get too much speed up. I loved it on my F650 twin.

Steve

Click to expand...

Hi Steve
Yes the NW 500 is a good ride. I have ridden around different parts of bonnie jockland many times but have never done the NW500 specific route. I didn't book anything so that I could make a decision as to clock wise or anti clock depending on the weather forecast. I ended up going anti clockwise and more or less always missed the rain. When the weather is kind I reckon you are hard pushed to beat Scottish roads and scenery; especially as it is so close. The only thing is that I hope the route doesn't become too popular and starts to attract the sort of policing/cameras the A9 now does. While I was there I was overtaken by 2 Audi RX jobbies going at a fair lick and some bikes too. A couple of the places I stayed at en route and on the NW 500 route itself said that the locals are starting to complain, so this may result in more robust policing. Still business is booming also which is good for the local communities.
Run the bike again today in the heat all good.

SuperTed said:

I had the same back in July coming home from a trip to the west country. Filled up at the services at the bottom of the M3 and went for the M25 to get to Essex.
Part way round the 25 the bike; a 2008 F800GS; hesitated and then cut just like it was running out, despite having almost half a tank still. After a couple of seconds; of abject terror on my part as I was in the middle lane with a damn great lorry behind me; it fired up again. Ran fine for a couple of miles and then did it again.
As the temperature was about 28C, which is exactly 82F, I knew what it was - vapour lock in the fuel tank.
Just to explain: this is when the fuel tank heats up inside due to the air temperature. So the pressure inside the tank becomes greater than that outside. So instead of drawing air into the tank it is trying to push air out. Thus stopping the fuel flow from the tank to the engine.
Simply stopping and opening the fuel cap solves the problem. My 1150 did this a couple of times and I could vent that on the move (clutch in, key out of ignition, open-close tank, key back in ignition, switch on, rev and go) but its not possible on the 800.
The bike did this several times on the M25 that day and I was convinced I was going to get creamed by a truck. Some bright spark has decided that a hard-shoulder is a waste of space so I was trying to get the bike sorted in the six inches between the nearside lane and the edge of the road - with cars and lorries coming by at 70 plus two inches off the right pannier. Not nice.

Click to expand...

HI Superted
Thanks for explanation regarding vapour lock. Nice to understand it now but not reassuring ref possible reoccurrence!! Must be sunny Essex, better move to cooler climes ...Scotland

I'm glad to see I'm not the only one...

I rode home from Croydon on Tuesday, in absolutely sweltering heat - 34 degrees was highest I saw. After about an hour of riding through traffic, then bombing down the A2/M2 at a steady 85, the engine cut out for a second or two. Scary! It did this a few times over the next mile or so, generally misfiring, and then when I stopped at a roundabout with traffic lights, it cut out at idle. Started OK. At the next set of lights (same roundabout) it cut out just as I pulled away, leaving me stranded. It was reluctant to start, but eventually did.

I limped for the next four or five miles to the next petrol station (it was about a quarter full, at a guess). Filled up, started ok, and was fine for the rest of the journey - maybe 20 miles or so.

I am also putting this down to the higher than normal temperatures and airlock/evaporation somewhere in the system (although I imagine they sell the bike in countries where temperatures are regularly this high and more). I can't think it's the higher air pressure in the tank - surely that would only encourage fuel down the fuel pump? But opening the tank and/or filling with fuel seemed to solve the problem.

Gordyman said:

Hi Steve
Yes the NW 500 is a good ride. I have ridden around different parts of bonnie jockland many times but have never done the NW500 specific route. I didn't book anything so that I could make a decision as to clock wise or anti clock depending on the weather forecast. I ended up going anti clockwise and more or less always missed the rain. When the weather is kind I reckon you are hard pushed to beat Scottish roads and scenery; especially as it is so close. The only thing is that I hope the route doesn't become too popular and starts to attract the sort of policing/cameras the A9 now does. While I was there I was overtaken by 2 Audi RX jobbies going at a fair lick and some bikes too. A couple of the places I stayed at en route and on the NW 500 route itself said that the locals are starting to complain, so this may result in more robust policing. Still business is booming also which is good for the local communities.
Run the bike again today in the heat all good.

Click to expand...

The problem is the motorcycle press hyping up these routes and giving them titles. Then uncle Tom Cobleigh and all head up there, which may well lead to an increased police presence. I have been riding most years in that area since 1976 (went up on a Suzuki GT250) and over the years the cops have been conspicuous by their absence, but more and more bikes have been appearing. I'm back there in mid October hoping for fuzz (and Midge) free roads.

I've had a similar experience on my 800 today, it stopped on me with a full tank as I pulled off Lancaster services, luckily I was still on the slip road, turned it off on the key, stabbed the button and up she went good as gold. Then ran all the way up to the other side of the Erskine bridge, where it died on me again, just as I took the slip road to head for Crianlarich - basically the first time I'd dropped the revs since leaving the services. I got it going again only for it to fail on the roundabout before Lomondgate services, - quite low on fuel by this point.

Filled up at the Esso there and just hoofed it up to Fort William, and it's not missed a beat all the way, weird!

I also seem to have a cooling fan issue, when I'm barrelling along the gauge sits bang on the halfway indicator, and never moves, but if I sit and let it idle, in heavy traffic or on a carpark for example, I can hear the fan kick in, but the gauge still climbs and the warning light flashes - then I have to switch off.

I can move the fan freely with my hand, it's not obstructed and the radiator looks fine - there's also plenty of water in the expansion bottle - any ideas?