Tuning the SV

Hey all

Firstly I'm new to the forum, having only recently joined the SV650 owners club (just bought myself a blue W reg number with a gorgeous and loud blue ART can!). Really loving riding the bike, a total culture shock compared to my last bike, a CBR400RR, but still totally suits my riding style.

Anyway, the main reason for the post is that I'm after a touch of help on performance.

I've tried the standard can on me SV, however, found that the bike actually runs better and indeed more smothly (much to my surprise) with the race can on it. Looking at the can, there isn't really much sooty carbon deposit at the end, so I assume it's running ok and not too rich. It does, however, still have the standard air filter in there and I was wondering if it's worth changing the filter for a K&N filter or whether I can get away with standard? Also is leaving the standard filter on likely to 'choke' the engine at all given I'm running it with a race can? Would I need to re-jet the carbs if I did replace the filter?

Also I've noticed that the engine seems to pull hard up to about 8,000 rpm, then it seems to run a little short on pulling power after that up to the red line. It's probably that I'm used to the peaky power of my CBR400, but just wanted the confirmation that this is normal, I assume this is the torque peaking around the mid range then it tapering off.

I did struggle a touch to keep up with my brother on his Triumph Speed 4 which i fully expected as his bike pulls more power and is a four after all, but was wondering how easy it was to tune the SV engine for a couple of extra horses so I could surprise him next time we're out?

Apologies for the lengthy request for my first post, just eagre to get the best from my SV!!!

Thanks

Jason

Hello and welcome. Where in west yorks are you ??

The bike running smoother with race can on sounds like it has been jetted specifically for the can. This would mean the original restricted ( in sound terms ) can wouldn't be as free flowing hence poor running. After that......i'm lost

[johnnyrod]

You will get a bit more from adding a K&N filter, but as it hasn't been done to your bike then the jetting might need altering to compensate. If you don't have any dyno charts then to be honest someone has probably just fiddled with it and hoped for the best. Get a proper dyno run to see what you're getting and where it's rich or lean.

A popular mod used to be shimming the carb needles to go with a louder can, this gives rich midrange but still lean top end, so could be why it's a bit breathless at the top - most of them will bang off the rev limiter happily. Proper setup is larger main jets (depending on your bike) and maybe Dynojet needles.

If you don't have it already get the ignition advancer Woodruff key (JHS racing, maybe others too), its about £20 plus fitting but gives loads of extra bottom end, plus a couple of horses at the top.

All in these mods should give you about 5-10% over stock power, after that perhaps hotter cams - if your bike is a curvy one, check this out:

http://forum.svrider.com/viewtopic.php?t=40489

They're great bikes, and with a few suspension tweaks you can make it even better.

Cheers for that mate.

I'll take a look at the carb needles and see if they've been shimmed. I'm going to give the carbs a good overhaul in general I think and check the jetting. Not quite got the brass for dynojetting the machine yet, but sure I'll get round to it shortly.

I also saw a couple of handy hints on that svrider website, think I'll have a look to see it the bike's being starved of air as they said this can have negative impact on performance at the top end. It recommended removing the foam from under the tank for a start. Anyone tried this?

I'm definitely going to make get involved with the ignition advancer. Looked on the site you recommended and it said they'll fit it for £30. Unfortunately, they're in Bristol which is a fair way away so I'll have to get me hands mucky!!

Although I find the standard rides nice, I just want mybike to do just that little bit more. And it seems I've got plenty of options open to get the most out of the SV!!!

Cheers
Jason

welcome to the forum, now kindly remove MY avatar from your avatar space! :P

Get a R6 throttle tube, makes it much easier to get on the gas. This will count when chasing faster bikes.

[northwind]

A UK-spec bike won't have shimmed needles- we get slotted needles as stock. Just FYI.

Don't worry about running the stock filter with the race can, that's very common. If you replace the filter you'll definately want to rejet- frankly a filter change that didn't lead to rejetting would be a waste of money. IMO the K&N is a poor option, the BMC Race RS (not the Race, specifically the RS) is far, far better. Also, removing the foam helped me a lot when I was running the Renegade filter, and is probably still helping a little now with the BMC. Tank spacers- mine are from Chewy22 on the forum- helped my top-end too. Definately worth losing hte foam, even if it does nothing for you it's free and easy.

With just a can, jets, filter, ignition advancer, you won't see a huge power boost. I'd say you'll be lucky to see 5bhp. But don't fixate on the power figures, if you're going to mess with an SV IMO it's far better to work on usability.

For example, the ignition advancer does very little for top end- on a harder tuned bike it actually retards top end- but it brings forward the torque and gives you a much broader working power band. Great mod. Likewise, the R6 throttle mod is fantastic, dirt cheap, easy and reversible. It just means you make better use of the power you have.

At the end of the day, you can't make an SV faster in a straight line than a 600 IL4, even a Speed Four. But, it should already be better on the brakes and in corners than the Speed Four (IMO) and you can do quite a lot there fairly cheaply to improve that further- quality brake pads, maybe some fork work, maybe a shock swap.

I removed the foam from under the tank on my sv today, a job I've done before. I discovered a useful little trick this time round though. Holts Damp start dissolves the adhesive beautifully, I then used an old bank card to scrape it off! would recommend gloves though, it makes a sticky mess. Would also recommend covering the bike if you're doing this with the tank in situ. Definitely stick some rag in the air intake to keep the crap out.

[yorkie_chris]

Whats the point of that foam?

As far as I can see all its for is damping down induction roar, any other purpose in life for it?

It's also good for getting wet, then holding moisture against the tank and making it go rusty!