urgent help required

Just fitted a new akrapovic system to my SV650S, I previously had a standard system with an ART end can and an Ivans jet kit + BMC filter, the bike run sweet. The jet needle was set to the second clip and mains jet was stock. After fitting the Akrapovic system I installed the recommended 150 mains jet and increased the neede height to the third clip. Now the bike doesn't want to rev and surges and splutters at anything over 6K revs. I've checked all the inlet manifolds and airbox seals for leaks and can't find any. Would be appreciated if anyone can suggest a possible fix or change of jetting, don't want to fiddle too much more at the minute until I get an idea whether I should lean it out or richen it up a bit.
Cheers,
P.B.

[rictus01]

Off the bat it sounds like too much air, what BMC filter are you using, if it's the RS race try obstructing a bit of it and see if that helps, if it does then you'll need the race and not RS version, worth a shot, obviously don't go riding it about with a bit of rag in there though , but it may just show you where to go.

Cheers Mark

It's the BMC race that came with the jet kit, it has a single inlet with no snorkel. I'll try duct taping half of the inlet and see how that goes today, yeah that should give me an idea if it's too much or too little air.
Thanks for the advice, a second opinion always helps.
Cheers,
P.B.

[northwind]

How big is the inlet? Is it most of the size of the top, like this:



Or is it smaller? If it's the big open top one, congrats, you have a Race RS which is basically as good as it gets with an airbox. Unfortunately you need hyowge jets for a Race RS too. I can't remember if I'm running DJ 180s or 185s, probably 180s, but it seems like my system flows a bit better than the Akra.

Don't know if your 150 is Dynojet or Mikuni, I think Ivans do DJs usually but 150 could be either. I'm going to assume they're DJ as your symptoms are exactly what I'd expect for that, I got the same when I fitted one on Mikuni 140s- if I was you, I'd put the stock filter back in like right now, since the bike's probably disasterously lean... If I'm right you should find that makes it a bit rich. I think the Ivans kit probably comes with tank spacers too, they're too good to miss stuff like that usually.

Then, hunt down... Oh, for Akrapovic with spacers, 170, 175 and 180 main jets I reckon. It's possible I have some somewhere but I'm not sure where they'd be, PDQ can usually deliver within a couple of days and they're just a couple of quid each. If you want to play safe or go cheap... Eh, at a guess, 170, with spacers. Don't quote me

No mine has a much smaller opening, I taped up half of the airbox opening today and took the bike out for a run to see if this helped or made it worse, the problem has got worse and has now dropped from about 6K to 4K revs. I was thinking that with the restricted airflow and the problem getting worse that maybe I was running too rich. I was going to raise the needle back up to the second clip tomorrow, heres' hoping for the best.
P.S.
The RS looks the dogs danglies but at the minute I'l just be happy to set up the one I have.
Thanks,
P.B.

[northwind]

Hmm. Somewhat surprised Can you tell me, with the other jets in the kit are there any that come in half sizes, like 147.5?

Just finished setting jet needles back to 2nd clip, unfortunately on babysitting duties so won't get a test run until tomorrow. As for the main jets the kit only came with 150s, recommended settings were clips 2 or 3 and standard mains on a standard system with slip on and the 150s for a full system. I have fitted spacers under the tank to raise it approx 8mm. Hope all goes well, would not be looking forward to pulling carbs out again to change out the main jets for smaller ones.
Cheers,
P.B.

[NedSVS]

The Ivans jet kit was designed for use with a modified K&N or BMC filter. Basically Ivans cut the top out of the K&N or BMC standard filter so it looks just like the BMC RS. Still doesn't breath quite as well as the BMC RS because the filter material is different too. It might be worth looking for a second hand K&N or BMC standard filter and cutting the top out.

Lowering the needles to the second clip definitely help but still stuttered at 8K revs +. I removed the air filter and the bike ran sweet. My BMC only has a small opening about the size of the standard suzuki filter, no snorkel however. I am considering enlarging the opening as far as possible without damaging the fibres and removing the foam from below the tank to maximise airflow. Is this feasible with the BMC or a waste of time?
I tried to add a pic of the filter but wasn't able to do it unfortunately.
Cheers,
P.B.

[northwind]

Ah, there you go then... I've never known an SV to be so rich as to give those symptoms, but NedSVS's comment sounds right to me.

You can desnorkel the stock filter in the way desribed as well but that'd probably lean you out- wish I knew whether those are Mikuni or DJ jets you have though.