Blocked air filter?

I've been having some running issues with my Curvy. It's been hesitating as I open the throttle and occasionally dying as I come to a halt. I was thinking either electrical or fuel.

Had a look at the rear plug yesterday and it was sooty. That elimimates a blocked fuel filter or jet IMO. Could still be electrical though. However I have an BMC road air filter and after a blast with compressed air it seems considerably cleaner. Could it be as simple as that? The filter's only done around 5k since it was fitted. I also pulled out the rear choke and that seems free.

While I had the tank off I also defoamed it.

[yorkie_chris]

If the filter had a lot of crap in it then it'll make it go rich, if it's rich in the mids then after getting it hot you'll notice a hesitation when getting back on the throttle after using engine braking. Different to a lean hesitation though, more like a "bleh" than a "bang" when it does rev.

Take it out with the cleaned filter and see what happens. Is BMC filter serviceable like the K&N's?

[northwind]

It is, but BMC say not to use compressed air, their instructions are all "Use only our special dirt removal stuff". There may be some truth to that, I used Pipercross cleaner on my BMC and it went a bit rubbish Or perhaps I just messed up. I've never yet cleaned a cleanable filter and had it work anything like as well as a new one

[embee]

...and double check the chokes aren't sticking........

(Edit - sorry, you've done that........must read the whole post!!!! )

The filter was dealer fitted and no instructions were given to me. I've found the BMC site and it reckons every 10k miles to clean and recoat it, so it more than likely wasn't blocked, plus I reckon I've cleaned all the protective oil off the filter now

You were half right Embee, I haven't checked the front choke.

Well, went out on it yesterday and it did seem to be better, not right, but better. However by the end of the day, 320 miles, it was pants again. But I haven't got the oil to coat it in, so that may have summit to do with it. Will get some proper cleaner and oil.

If it was only 'sooty' on the rear then it is not going to be something that affects both cylinders (air filter).

EDIT: you did check the front too right?!?!!

If you have checked the choke, then how about:-

• Sticky* rear float valve?
• blocked air jet
• blocked/dirty emulsifier tube?

If the plug is sooty, not wet, then it is more likely to be carburettion than electrical ...

I think you need the carbs off I am afraid ...



*or has muck on/in the valve seat.

Originally Posted by Blue_SV650S

If it was only 'sooty' on the rear then it is not going to be something that affects both cylinders (air filter).

EDIT: you did check the front too right?!?!!

If you have checked the choke, then how about:-

• Sticky* rear float valve?
• blocked air jet
• blocked/dirty emulsifier tube?

If the plug is sooty, not wet, then it is more likely to be carburettion than electrical ...

I think you need the carbs off I am afraid ...



*or has muck on/in the valve seat.

No I was being lazy Blue and only checked the rear. That was enough to dismiss a couple of things in my book Yeah the plug wasn't wet.

It's going to JHS next week so I'm loathe to fiddle as we need the bike for NW3.5 this weekend.

I did wonder about a valve.

Originally Posted by petevtwin650

No I was being lazy Blue and only checked the rear. That was enough to dismiss a couple of things in my book Yeah the plug wasn't wet.

It's going to JHS next week so I'm loathe to fiddle as we need the bike for NW3.5 this weekend.

I did wonder about a valve.

Its more likely to be a blockage/**** in there than anything broken ...

How easy is it to get the the drain plugs on the SV's carbs with them in place?????

If you open the drain plugs and let the contents of the carbs drain out, it might be enough to clear it .. if you think about it, when in use the floats only move a minimal amount, so it is hard to clear muck, if you drain the carbs, the float flops right down ... there is a good chance any little bit of muck will get washed away during the drain ... worfffff a go~!!

Any idea folks if I can get to the drain holes with everything in place.

Cheers Blue