Please help with my '01 SV650

[DarkLord]

Hey all

I have a wee problem and it has me absolutely stumped.

I have a 2001 SV650s and it seems to have this consistent flat spot. It's like if you are sitting at about 5-6,000 RPM and give it a little bit more gas, the revs seem to drop substantially before picking back up. The same thing happens under hard acceleration as well. The owner of the bike before me says it didn't do this when he had it, so we are both a bit confused.

I have had the carburetors checked, cleaned and balanced, I have run some motor up fuel cleaner through it, I have had the valve clearances checked, spark plugs checked (which are apparently fine) as well as an oil and filter change, plus I've started running 91 instead of 98, yet nothing seems to fix it. The bike has a Scorpion free-flowing exhaust fitted and I am fairly sure it is running on standard jetting.

It can be easy to overlook on a first time ride but after spending quite a bit of time riding it over the last month or so I have become quite aware of it. It is nothing major as far as I can tell but it is frustrating and it is a nuisance when trying to pass cars etc as you have to put up with what feels like a large lag in the acceleration before it actually kicks in.

Does anyone have any ideas what this could be. Perhaps water in the fuel lines? should I put some Iridium spark plugs in? Does it need to be rejetted?

Any suggestions welcome.

Thanks heaps in advance,

Graham.

[boman]

Have you looked, and asked http://www.sv-portal.com/. It is Spankme's other child. Dedicated to Sv's, 650 and thous.

Give them a looksee. They run a bit behind us, because alot of the members are Americans or from Europe, but they will come up with an answer. If they havn't already.

[breakaway]

Someone please help this dude out. I sold him my SV650S, it was running perfect, and it went to shit almost overnight after I sold it to him. Was running perfect before I sold it.

[grusomhat]

Someone please help this dude out. I sold him my SV650S, it was running perfect, and it went to shit almost overnight after I sold it to him. Was running perfect before I sold it.

Either you just didn't notice the flatspot or he had done/is doing, something different with the bike. I'd likely say the latter as you say it was running perfect.

Something must be different. I'm pretty noobish but maybe slack in the throttle cable or something other than the engine?

[DarkLord]

Either you just didn't notice the flatspot or he had done/is doing, something different with the bike. I'd likely say the latter as you say it was running perfect.

Something must be different. I'm pretty noobish but maybe slack in the throttle cable or something other than the engine?

I haven't done any mods or anything to it at all. Perhaps I am just revving it differently and this has made it more apparent or something??

Could it be slack in the throttle cable? How can I test this?

[Ixion]

Different fuel?

Could you get the previous owner (Mr breakaway) to ride it now and see if he notices the problem? If not, then it may be simply that he has/had become so used to it he rode around it without noticing it. Easily done when a fault comes on very gradually.

Otherwise, this is a problem that can only be diagnosed by someone familiar with the model - an owner/ex owner or a bike shop.

[davebullet]

http://forum.svrider.com is another great resource. For example:
http://forum.svrider.com/showthread....at+spot&page=2

Talks about flat spot / spluttering similar to what you've described. Most of the feedback talks about carb cleaning (which you've done) or water in there somewhere. I don't know about the water thing since it is revs specific.

I'd be inclined to move into the timing area. I know for emissions testing, many bikes are leaned out in the 5,000-6,000 area, causing poor running. My FI K3 sounds almost like it is missing. A dyno tune is probably the only way to fix the problem for my bike.

Maybe breakaway didn't notice the problem and it was there all along.

[PirateJafa]

Didn't you also sell a CBR400 to some dude, Breakaway, who was rather unhappy to find out later that you'd thrown it off the road onto a rocky beach?

[grusomhat]

I haven't done any mods or anything to it at all. Perhaps I am just revving it differently and this has made it more apparent or something??

Could it be slack in the throttle cable? How can I test this?

I wouldn't have a clue, was just guessing and something that's related to acceleration Sorry. Thinking about it I would imagine it throttle slack would be pretty obvious and wouldn't cause what you are talking about. Forget that.

Are all the air intakes on properly and nothing blocking any of them? That could definitely cause what you mention.

[DarkLord]

I've had it checked out by a couple of bike shops, no one really seems to be sure.

The most recent one recommended I try running 91 rather than 98 which I was running at the time, however that didn't really make any difference.

I've thought of perhaps putting some iridium plugs in it or something - perhaps that might make the difference?

[breakaway]

Didn't you also sell a CBR400 to some dude, Breakaway, who was rather unhappy to find out later that you'd thrown it off the road onto a rocky beach?

Negative. I told him exactly what I did to it, and he still bought it. And it was still running well when I sold it on. In fact, a quick carjam check shows its still on the road (Just got a WoF on the 17th Dec).

Easily done when a fault comes on very gradually.

While I cannot discount this possibility, I'm not one of those "I know nothing about this bike" people, I've owned another SV650 before that one and it was identical to that one - its unlikely that both SVs had the issue.

[BigOne]

one of the best rescources I ever saw for the carbed SV650 is a site in England run by a guy called Catpoopman. search and you'll find it.
I suggest that the flat spot was always there, the stock engine (carbs set-up) was chronic for it.
You need to start with 40thou of 3mm washers (usuallytwo) under the needles, and then slightly larger jets, 145s I recall. This is almost mandtory for the Scorpion can. You will see a major improvement immediately.
The stock Suzi air cleaner is better than any aftermarket filter, but make sure it's clean (ish) or get a new one. Disable the TRE, it's a simple snip of a wire, Again, all this is on Catpoopman's site.
Also look at SoCalSV650, in California, SVDownUnder (Aussie) and SV.Org, Britain.
www.geocities.com/catpoopman/Johns_bike.
html

PM me if you like.

BigOne.
I ran a roundy for 6 years, and there is not much I didn't try

[DarkLord]

I just got a reply from someone on the SV Rider forums and they have had similar problems, put a Factory Pro 1 jet kit in and that has apparently solved the issue.

Any idea where I could get one of these and how much?

[breakaway]

http://cgi.ebay.com/ebaymotors/99-02...Q5fAccessories

Edit: Before you go ordering shit, lift off the tank and crack open the airbox and check the air filter too. Also, really basic I know, but have you checked the choke?

I'm 110% positive this issue was not there when I had it - I have on many ocasions gone from 30% to 90% throttle on that bike, and it didn't hesistate even once. Just picked up and went with me and my mrs holding on for dear life.

[DarkLord]

Bump -

Better description of the issue - if you are sitting at about 4,000 revs or so (sometimes higher, sometimes lower) for about a kilometre or so, and open the throttle even just a bit, it lags and the revs drop before it suddenly surges forward. It often happens at low revs, for example turning a corner in a 50 zone. It will cough and splutter as if no fuel is getting through, then all of a sudden surge forward like crazy, like it gets a big gulp of fuel at once.

I've changed the fuel I was running in it, put some meths in the tank to try and dissolve any water that might be in there. I've taken it to one of the bike mechanics in Taupo and he says he's never seen anything like it before.

From what I have gathered by looking at other sites online, it seems as if people have had this same issue with this model (2001 SV650s) and a K&N air filter and a Dynojet kit have solved the problem so I'm pretty certain I'm just going to bite the bullet and go with that.