Loss of power..... - SV650.org

20-10-04, 11:02 AM

Howdy,
It's going to the garage for this anyway, but just wondered what the resident experts think.
When I'm cruising on the Motorway at about 5k revs and nail the throttle, there's a big lump of nothing before the power kicks in, just for a second. If I open the throttle slowly, it's all lovely and smooth and progressive, just when I open it wide it seems sort of like the bike's taking a huge breath before giving me any grunt.
Anyone know what this might be? I had it serviced a month ago and it started doing it shortly after.
My thoughts are: Unbalanced carbs or possibly a mixture issue.
Any ideas??

20-10-04, 11:11 AM

Last time I had that it was the carbs out of balance, as I don't think this is part of servicing.. maybe on a major service. It was out by 4cm's, I think the guy charged me about 80quid... not sure as I had a service at the same time.
Or it could be you fuel mix if you've had a new filter and 'race' can as this can make things slugish. Though normally you get popin from it firing out unused fuel.

20-10-04, 12:06 PM

One of the same symtoms i'm getting too with mine....

i'm just short of 12000 mile service so could be the balance ?

20-10-04, 04:47 PM

both my bikes do it,
im gonna tighten up my chain in a min so ill let you know if that has anything to do with it

20-10-04, 05:02 PM

Isn't this the revs at which noise tests are done? Most bikes have a dip in the power curve at this point to enable the bike to pass the noise tests.

northwind · 20-10-04, 09:33 PM

I just started getting exactly that too... (before I binned it, before anyone asks). Haven't changed anything at all on the bike for about 500 miles so I'm guessing it's carb imbalance or similiar, the bike runs very happily under pretty much all conditions except when run at around 5000 revs for a short bit then opened up fast- big drop in power (kicks me forward on the seat, so it's not just slow delivery, it's an actual drop, though not as bad as losing a cylinder) then it kicks in again.

Well, I'm due a proper rejet anyway, I'll wait till I ditch the Rene filter and do the cams and then get the pros to do it.

20-10-04, 10:09 PM

Me thinks you open throttle quick and all the reserve air in the airbox is taken up. This would indicate blocked air filter (need cleaning/replacement?).

northwind · 20-10-04, 10:12 PM

Nah, the Rene hardly even counts as a filter, it's more or less a sock stretched across the opening... Sides, if the filter was obstructed it'd run badly all the time...

20-10-04, 11:40 PM

Mines always done that,Don't worry about it

northwind · 20-10-04, 11:57 PM

Not worried, but I want it to stop... Snce it never did it for the last 5000 miles, and now suddenly it does, I know it can be fixed, and it's kind of annoying.

20-10-04, 11:02 AM	#1
Nekkid Guest Posts: n/a	Loss of power..... Howdy, It's going to the garage for this anyway, but just wondered what the resident experts think. When I'm cruising on the Motorway at about 5k revs and nail the throttle, there's a big lump of nothing before the power kicks in, just for a second. If I open the throttle slowly, it's all lovely and smooth and progressive, just when I open it wide it seems sort of like the bike's taking a huge breath before giving me any grunt. Anyone know what this might be? I had it serviced a month ago and it started doing it shortly after. My thoughts are: Unbalanced carbs or possibly a mixture issue. Any ideas??

20-10-04, 09:33 PM	#6
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,082	I just started getting exactly that too... (before I binned it, before anyone asks). Haven't changed anything at all on the bike for about 500 miles so I'm guessing it's carb imbalance or similiar, the bike runs very happily under pretty much all conditions except when run at around 5000 revs for a short bit then opened up fast- big drop in power (kicks me forward on the seat, so it's not just slow delivery, it's an actual drop, though not as bad as losing a cylinder) then it kicks in again. Well, I'm due a proper rejet anyway, I'll wait till I ditch the Rene filter and do the cams and then get the pros to do it. __________________ "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"

20-10-04, 10:12 PM	#8
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,082	Nah, the Rene hardly even counts as a filter, it's more or less a sock stretched across the opening... Sides, if the filter was obstructed it'd run badly all the time... __________________ "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"

20-10-04, 11:57 PM	#10
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,082	Not worried, but I want it to stop... Snce it never did it for the last 5000 miles, and now suddenly it does, I know it can be fixed, and it's kind of annoying. __________________ "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"

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20-10-04, 11:11 AM	#2
Grinch Guest Posts: n/a	Last time I had that it was the carbs out of balance, as I don't think this is part of servicing.. maybe on a major service. It was out by 4cm's, I think the guy charged me about 80quid... not sure as I had a service at the same time. Or it could be you fuel mix if you've had a new filter and 'race' can as this can make things slugish. Though normally you get popin from it firing out unused fuel.

20-10-04, 12:06 PM	#3
Iansv Guest Posts: n/a	One of the same symtoms i'm getting too with mine.... i'm just short of 12000 mile service so could be the balance ?

20-10-04, 04:47 PM	#4
Warren Guest Posts: n/a	both my bikes do it, im gonna tighten up my chain in a min so ill let you know if that has anything to do with it

20-10-04, 05:02 PM	#5
Mariner Guest Posts: n/a	Isn't this the revs at which noise tests are done? Most bikes have a dip in the power curve at this point to enable the bike to pass the noise tests.

20-10-04, 10:09 PM	#7
snoopy Guest Posts: n/a	Me thinks you open throttle quick and all the reserve air in the airbox is taken up. This would indicate blocked air filter (need cleaning/replacement?).

20-10-04, 11:40 PM	#9
Graham Guest Posts: n/a	Mines always done that,Don't worry about it