another f800 stalling thread (solved)

ok. so ive read what seems like hundreds of threads on this situation. heres mine.

2010 f800gs 33,000 miles. has rough idle after fully warmed up. the bike shuts itself off after long highway runs coming to a stop, sometimes if i pull in the clutch and coast into a turn it will die after a second of holding in clutch lever. if i blip the throttle at a stand still in neutral or in gear with the clutch in sometimes it will die and sometimes the idle will just drop down to about 800 and then bring itself back up. the problem is very intermittent but the 2 things that remain consistent are:1. after the bike is fully warmed up is when the problem starts. 2. the bike will start back up with the starter button and no need to cycle the key. also the bike does not pop any codes when this happens.

the first time this happened i had been on the highway for about 3 hours, i had gotten off the highway in pine az onto a trail which is quite higher in elevation than phoenix where the bike is usually ridden. i went down a steep hill and as i was climbing back up the next i pulled in the clutch going over a large rock and the bike cut out. i pushed the starter button and the bike started right back up and on i went. about 30 mins later as i was stopping for a light about to get back on the highway home the bike stalled again.

while on the highway home there was a lot of wind so it could have just been strong winds but the bike felt like it lost power at one point, i was full throttle and the bike seemed sluggish (i was not increasing speed). so i pulled over at the next exit and taped up my airbox holes thinking maybe the computer didnt like that modification. that didnt fix anything.

i do have a power commander and a yoshimura slip on + a uni filter and the airbox cover holes drilled. i have since disconnected the power commander, plugged the o2 sensor back in, reset adaptations, calibrated tps and iac, removed iac and cleaned, checked fuel vent. the stalling is happening more and more as time goes on.

honestly my iac looked fine, was almost perfectly clean. my iac hoses are the new style and have no cracks whatsoever.

i was able to find one thread on f800riders where 1 guy had this same problem and the fuel pump was the issue. with plenty of experience with Japanese bikes this does not seem like a fuel pump to me. usually a fuel pump will just die or it will have low pressure no matter the temp but at this point i am leaning toward the fuel pump.

any help appreciated.

Hi there, so I had the most recent issue on here with similar symptoms.

The symptoms for me were always in higher ambient temps, after a sustained higher speed run, after slowing down and then riding at slower speeds bike would stall and die, either coming on the throttle or coming off. The issue was only apparent to me on a part full tank, my theory is the fuel cools the pump.

Essentially I reckon fuel pump gets hot, things expand and are not in tolerance, when it then slows down (as speed slows) and the pump seizes in some way.

Anyway changing the fuel pump cured all symptoms. I have run the bike up to 35 degrees Celsius fast, slow, on/off road and everything inbetween.

It sounds very likely to be the pump and even if it isn’t it is a cheap thing to eliminate if you can change it out yourself!


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its good to hear that another person with the same symptoms has cured it by changing the fuel pump. a lot of people would like to say if you dont have to cycle the ignition that it is not the pump. i have a $60 high flow pump on the way so well see what happens. either way at this point im so fed up with it that $60 to narrow down the problem doesnt phase me.

Agreed, it’s an easy change as well really.

My tips would be, drain the tank before or run it down to about a quarter full, take your time when reseating the pump assembly in the tank as the seal is fiddly to seat correctly, I found it best to put the seal in the tank and slide the assembly in using some flat head screwdrivers to stop the seal being taken into the tank with the assembly. Also when you think you have done it all fill the tank slowly and check for leaks at the seal. First time around I just threw all the fuel in and had a major leak loosing a few litres of petrol on the floor!

Also take care when removing the fuel lines if the bike has just run as they will likely still be under pressure so you will get a face full of petrol!! (Don’t ask me how I know this!!)

Let us know how it all goes or if you need any other advise!


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Do the filter at the same time while its all apart

This likely isn't a total waste of $60 and time, not at this stage of the bike's life.....it could be coming due anyway. I'm betting this is the issue.

i have seen the external filter threads, i might go this route, not sure yet.

im with you on that, especially with the pretty awful quality of gas we have here in the desert, its really only a matter of time.

Just posted about this before seeing yours here. The symptoms are almost identical to my 08 1200 that had a bad/recall pump, so I was leaning towards fuel pump change before noticing that my fuel pressure sensor failed a bench test.

Daryloftexas, since you have a 911, do you know what fuel pressures you're seeing? Mine is never outside of the 4500s, but I have no idea what's normal or if you see a drop before dying.

Just replace the filter with a new one and get another 50,000km, they are 10 bucks.

Introducing another failure point doesnt make any sense to me

you mean the screen on the pump? the new pump comes with a new screen. i have made that mistake in the past with a subaru, the new pump only lasted about 5,000 miles with the old screen. never again. haha

let me get back to you on that.

No, the main Mahle KL 315 filter sits in the pump unit

ohhhh i see.

My 2010 F650GS tends to die (rpm goes down) before picking up, when i accelerate from complete stop. Just ordered a fuel filter. Hopefully the problem will go away once i change the filter.
Does anyone know if this could be a badly adjusted cable issue as well?

Thanks
Sree

my filter and pump arrived today, i will update after ive ridden it in hot temps enough to determine weather its solved or not.

Total waste time and money, I had analoge simptome on my 2012 gs. One solution; before ordering fuel, air filters, fuel pump, or new bike , please clean fuel tank breathing pipe, near side stand.
Good luck

BD, where did you get one in Oz for a tenner? Getting to the idle time of the year and I want to do the filter.

sorry, it was about 40

https://www.ebay.com.au/itm/Motorcy...948022?hash=item4d62da2fb6:g:83EAAOSwjt5ailsq

They are readily available from a number of places. I got half a dozen from Germany at about $35 each. I wouldn't bother with the external filter, it's just as easy to change it in the standard setup. I would suggest a new filter every 20k, and maybe a new pump at 40k, they are cheap enough too.

When I had issues the breather was fine. If it was the breather the issue would be more constant whereas most people discover this issue in high ambient temps


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