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.:headbang:

[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.php?t=83432&highlight=flat+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? :sherlock:

[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? :sherlock:

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-Suzuki-SV650-Factory-Pro-carburetor-jet-kit-stg-1_W0QQcmdZViewItemQQhashZitem518a4f49d6QQitemZ3502 12803030QQptZMotorcyclesQ5fPartsQ5fAccessories

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? :dodge:

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.

[Pussy]

The carbed SV really needs re-tuning when you change the exhaust.
The enrichening jets can sometimes stick in the carbs.
Ray Clee or Triplezee Dyno in Auckland would be worth talking to

[DarkLord]

The carbed SV really needs re-tuning when you change the exhaust.
The enrichening jets can sometimes stick in the carbs.
Ray Clee or Triplezee Dyno in Auckland would be worth talking to

Would a jet kit and air filter upgrade fix it, or would it be worth just taking to a dyno?

[breakaway]

Have you been using the choke to start the bike?

[DarkLord]

I use it to start it but always turn it off afterwards. Most of the time it really struggles to start without the choke.

[Pussy]

A jet kit fitted in conjunction with the dyno time will sort it.
It's worth paying a few bucks to have it done right.
We used to have a K1 SV650S in this household... I fitted a full yoshi system and a K&N filter. I got Brian Bernard to fit the dynojet kit, and optimise it on a dyno. Brian got the bike fuelling very nicely

[breakaway]

Can you please pull the plugs out and see what the business end looks like? I have a funny feeling the plugs are culprit. They fit the description you give.

[BigOne]

Darklord, I was just checking back to this thread, and another thing occured to me. I had a problem with my roundy, with rusting of the choke cables after the splitter, right inside the steel bend where the cable enters the carb. The cable rusted in the bend and siezed the cable with one or both chokes choke part open. I fixed it with new stainless steel cable from the bicylce parts bin in my garage.
After opening the choke to start the bike, the choke would stay open even tho the lever was returned.

How did you get on with your issue? You didn't call or PM me after I sent you the links to Catpoopman's site.

[DarkLord]

I'm 99% sure I have this sorted now.

A few people mentioned that they wondered if it was running slightly rich. Not much but a little. So I ended up getting the carbies adjusted to lean it up slightly. I took it out to my place of work and back today (about 30 k's each way) and despite a minute hiccup here and there it didn't cough, splutter or surge at all.

I actually wonder if what has been happening is that as I've been sitting at a certain rev range for a time, the carburetor has been slowly filling up with extra fuel, and once I have opened it up a bit more, it has just coughed and spluttered on the extra fuel until it finally got through all of it and returned to normal, hence the surging sensation. This would also explain the flood of brown shit that came out of the exhaust when I ran some carburetor cleaner through it.

I may be completely wrong but that is my hypothesis anyway.

[BigOne]

DarkLord,

do you know exactly what was adjusted? Perhaps the bike is not stock, but someone has been in the carbs before you.
If the bike is still stock except the open pipe, it will go Heaps better if you change the stock 137.5 mainjets for 142.5 mainjets, raise the needles 1 or 2 shims (1 or 2 x 3mm washers), and adjust the idle jets to 2.5 turns out. These bikes have a lean flat-spot and retarded ignition in gears two and three, and it's easy and quite interesting to fix.
Read the stuff I sent you. I'm not sure why you didn't give me a call, there is a lot I could tell you, and I actually know what I'm talking about.
A carb can't 'slowly fill with fuel' unless the needle valve is badly worn, and if it is, you need to fix it. The float level is fundamental to correct carb operation. This issue is discussed in detail in the material I sent you, too. Did you ever read it?

[BMWST?]

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).



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.

it is very likely that both SV have the same carburetion issue...

[BigOne]

DarkLord, did you read any of the stuff I sent you?
Sorting out the carbs on these bikes is not rocket science. It's all been done before. The keen guys who bought the early ones did all the experimentation, the dyno runs, etc, and they wrot it all down, so guys like you could benefit from it, if you you can be bothered.
You don't need a dynojet kit (expensive) or an aftermarket air filter, unless it's dirty, in which case get a Suzuki one, they are better than the others. You don't really need to take it to a dyno unless you are after really sharp performance.
You DO need to read the manual and notes I sent you, get a few basic tools, buy about $30 worth of jets, a few washers, and strip and service your carbs yourself.
You need two mainjets, 140 or 142.5, and 4 x 3mm washers, about 0.020" thick. And adjust the idle jets 2.5 turns out, after drilling out the plugs. It's all in the stuff I sent you.
If the carbs are dirty, strip and clean them. If a flood of crap came out the exhaust, imagine how much sh*t is still in them!

I have 6yrs experience with the 01-02 SV650, and there is a lot I could help you with, but you can't be bothered ringing. From your recent post, I doubt you read anything I sent you, either.

Breakaway says it's a stock bike, so unless it was made in a different factory on a different day, it will have the same issues as all the other SVs ever made.

[breakaway]

Also since that SV650S is canadian spec, it has a different shaped airbox. Trying to fit a K&N airfilter won't work. A mate of mine has a canadian spec bike, and he had to get a air filter made up since the K&N replacement filter wouldn't fit. This is because the canadian spec ones have different size fuel tanks than the other SV650S.

[rok-the-boat]

If the pipe is non standard I'd suspect that for a flatspot. Up the jetting one size, or two, that's what I'd try. Or, do you have the original pipes to test?

[breakaway]

I recently bought another SV650S (because they're such great bikes I couldn't keep away from them :p for the Mrs). This is a 2002 SV650S with standard exhaust / air filter and 12,000 km on the clock (12,000 legit kms too!) After her first ride on it, she bitched to me about a flat spot. I looked at her like she was silly, because I just raped and pillaged it back from wellington the previous day and it didn't skip a single beat for over 600km.

So I went out to ride it with her on the back to try to figure out this 'flat spot'. I accelerated like I normally do, and there was no surging or anything. Asked her "What the hell are you talking about? There's no flat spot here". She said "Slow down a little, accelerate slowly like I would". So I did. And lo and behold, the bike surges (very slightly) between 3500 and 5000rpm. But this was with VERY slight acceleration. Mind you I'm no hoon when I'm accelerating (I accelerate at somehwat a brisk pace (I can't eplxain this to you.. you have to figure it out yourself). I just twist the throttle more.

So maybe that's your problem? Does using more throttle solve the problem?

[BigOne]

the problem is solved by fitting bigger jets, and a few other minor adjustments. See my post on the 22nd Jan, just above. This flat spot is well known and the fix is well documented. You will find that if you do the mods the bike will pull like a schoolboy, across the entire rev range, especially up hills and two-up.
If you want a copy of an excellent document on the subject, by MickK of SVDownUnder, PM me. Mick wrote this up, building on the work done by John Callaghan, England (aka catpoopman)

[imdying]

The man when it comes to these is Zoran from the Twin Works Factory. Pop onto his forum and ask him about it, or use the shout box on eviltwinsbk.com. Either way, he'll be happy to help.

[kiwifruit]

Also go and see Chris Mitchell on Oruanui street if you continue to have issues, he is the best in town, tell him i sent you.

[FROSTY]

whereare you darklord? If In dorkland come over here for a yak sometime.Theres just a small possibility I might know some tiny smidgen about SV650's -especiallly carbied ones.

[DarkLord]

Chris Mitchell is the one who's been looking at it for me, and just fitted me a new rear tyre as well.

By leaning it up slightly the problem seems to have been substantially improved, yet after a good chat with BigOne last night I am thinking very much that due to the age of the bike and the k's it's done, the jets and needles are probably worn quite substantially and it will need the jets and needles replaced, and that leaning it up, although has reduced the surging substantially probably hasn't really hit the root of the problem.

Assuming I can get good prices and a good deal I am thinking of doing the work myself, however I am quite a mechanical n00b... anyone not too far from me with experience in this kind of thing who would be happy to lend a hand while I do this? I shall pay you in beer :-)