Starting /rough running problem - SV650.org

25-01-05, 02:21 PM

2001 SV650S

Never had a problem before but yesterday morning it was very reluctant to start. Something like about 5 mins of turning over the engine without it firing. Tried leaving it for a bit and then trying again in case it was flooded. No avail. It did eventually start, I was amazed that the battery lasted out so well.

After that it didn't start easily even when hot.

Last night and this morning the same thing, very long time before firing.

Last night it was running very rough - coughing and spluttering especially at low revs and not idling at all. This did eventually clear but it was still not running very well.

I have heard somewhere that water getting into the petrol can be a problem and have wondered about this. At all events it would seem to be something that has happened suddenly.

Has anyone got any ideas.

northwind · 25-01-05, 03:39 PM

Something bad to do with the fuel, I'd reckon, but I've not had that same fault- water in the fuel could be it, but IIRC is only usualyl a problem when you're right at the bottom of the tank- have you run the bike dry recently? have you had the tank up recently- could possibly be a kinked hose somewhere...

Did the problem vary at different points of revs? Ie did it clean up at high revs or was it across the board?Bad fuel/bits in the fuel could have gummed up your carbs...

I'd wait to get an opinion from someone who's had a similiar problem but I suspect the only way to be sure will be to strip the carbs and clean them with carb cleaner, plus check that everything's together and working in there.

I had one day's terrible running which sounded similiar to what you have, which I put down to a blockage in something fuel-related, as it passed on after one good high-speed blast. But I stalled at every set of lights and had to slip the clutch for ages at lower speeds all day...

Sid Squid · 25-01-05, 03:45 PM

Sounds very much like contaminated fuel, you'll need to empty the carbs.

There are two 5mm headed socket screws facing each other in between the carbs on the float bowls, they can be awkward to get to, especially so as they can also be difficult to see, undo them a few turns each and allow the contents of the carbs to run out completely, screw them back in again but don't tighten them too much, the carb bodies are made of a light Zinc alloy which is quite soft. When that's done, try to start the engine, don't be disheartened if it doesn't start right away, the fuel needs to fill the pump, hoses and float bowls, this can take up to 20-30 secs somtimes.

25-01-05, 03:49 PM

Wouldn't it be necessary to drain and refill the tank as well?

Sid Squid · 25-01-05, 04:01 PM

In an extremem case of contamination, yes, but it's far more likely just the carbs.

26-01-05, 04:18 PM

Thanks very much for the advice.

Today the bike started normally and seems to be running fine. Given that it is very cold to start messing on the engine, I am going to interpret this as it has cleared itself (drawn through whatever it was that it didn't like).

If it comes back, I will know what to do.

Again thanks.

25-01-05, 02:21 PM	#1
Sholay Guest Posts: n/a	Starting /rough running problem 2001 SV650S Never had a problem before but yesterday morning it was very reluctant to start. Something like about 5 mins of turning over the engine without it firing. Tried leaving it for a bit and then trying again in case it was flooded. No avail. It did eventually start, I was amazed that the battery lasted out so well. After that it didn't start easily even when hot. Last night and this morning the same thing, very long time before firing. Last night it was running very rough - coughing and spluttering especially at low revs and not idling at all. This did eventually clear but it was still not running very well. I have heard somewhere that water getting into the petrol can be a problem and have wondered about this. At all events it would seem to be something that has happened suddenly. Has anyone got any ideas.

25-01-05, 03:39 PM	#2
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,082	Something bad to do with the fuel, I'd reckon, but I've not had that same fault- water in the fuel could be it, but IIRC is only usualyl a problem when you're right at the bottom of the tank- have you run the bike dry recently? have you had the tank up recently- could possibly be a kinked hose somewhere... Did the problem vary at different points of revs? Ie did it clean up at high revs or was it across the board?Bad fuel/bits in the fuel could have gummed up your carbs... I'd wait to get an opinion from someone who's had a similiar problem but I suspect the only way to be sure will be to strip the carbs and clean them with carb cleaner, plus check that everything's together and working in there. I had one day's terrible running which sounded similiar to what you have, which I put down to a blockage in something fuel-related, as it passed on after one good high-speed blast. But I stalled at every set of lights and had to slip the clutch for ages at lower speeds all day... __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

25-01-05, 03:45 PM	#3
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Sounds very much like contaminated fuel, you'll need to empty the carbs. There are two 5mm headed socket screws facing each other in between the carbs on the float bowls, they can be awkward to get to, especially so as they can also be difficult to see, undo them a few turns each and allow the contents of the carbs to run out completely, screw them back in again but don't tighten them too much, the carb bodies are made of a light Zinc alloy which is quite soft. When that's done, try to start the engine, don't be disheartened if it doesn't start right away, the fuel needs to fill the pump, hoses and float bowls, this can take up to 20-30 secs somtimes. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

25-01-05, 04:01 PM	#5
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	In an extremem case of contamination, yes, but it's far more likely just the carbs. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

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25-01-05, 03:49 PM	#4
Carsick Guest Posts: n/a	Wouldn't it be necessary to drain and refill the tank as well?

26-01-05, 04:18 PM	#6
Sholay Guest Posts: n/a	Thanks very much for the advice. Today the bike started normally and seems to be running fine. Given that it is very cold to start messing on the engine, I am going to interpret this as it has cleared itself (drawn through whatever it was that it didn't like). If it comes back, I will know what to do. Again thanks.