your views or advice please

[graham1963]

Got my storm couple of weeks ago, done a short run about 50 miles ran perfect, 2nd run after 40 miles stopped for a coffee, started it up and it ran terrible only really at low revs, blipping the throttle from tickover to about 3000 revs. Took it to my local mechanic (not main dealer) new plugs, carbs off, jets changed to standard ones (had larger ones in) carbs balanced, made no difference to the problem. Mechanic said it had a k&N air filter, he sprayed it with filter oil and problem solved. My question is would a standard air filter solve the problem as opposed to spraying oil on the k&N filter. Any advice appreciated, thanks.

[sirch345]

Graham,
Fitting a standard air filter will most definitely mean you won't need to use oil on it, if you do you will ruin it.

If your bike is definitely all back to standard then I'd recommend fitting a standard air filter anyway.

Chris.

[Phil-VTwin]

But the up side of a K&N filter is that you dont have to buy an OEM one ever again

[tony.mon]

If your bike ran fine for 50 miles, then played up, it's not the filter.
No filter problem would affect the mixture so badly when it ran ok before.

Either your mechanic touched something else when he sprayed the filter (pipes refitted correctly on the tank?) or it was just a coincidence.

Spraying oil on the K&N would only allow less air in to the engine; if you used loads it would make the mixture richer, but that means you had suffered a sudden event that weakened the mixture.

Filter's a red herring, I'm afraid.
More likely partially blocked jet?

[Pete.L]

Choke plunger sticks and gives the same symptoms and occasionally a carb slide can stick and dump too much fuel on a plug.
Either way once the plug is crapped up with soot they run like poo

Pete.l

[graham1963]

Hi pete, mechanic says the throttle slides (think thats right) are drilled, possibly had dynojet kit fitted, i cant believe that just a k&n filter would make this much difference to the running, as i say its been ok for about 100 miles,also been told the choke is working fine,

[Pete.L]

The next time it happens you'll have to pull out your spark plugs and see if one is fouled again.
If one's looking black and horrible then there's going to be a fault with that carb. Now you've got the std jets back in it could be as simple as a bit of dirt causing a float to stick, or maybe the fuel mixture (piolet jets) haven't been returned to std. You'll have to keep tabs on any symptoms you can, just washed it, just caned it, been burbling around town, only when it hot etc and hopefully a pattern will emerge to give us a better clue. Might even be as simple as vapour lock and just opening the tank cures it for a few more miles.
keep us posted if it happens again and we'll take another stab.

Pete.l

[graham1963]

yes air filter changed for a standard one and the problem is still there, totally stumped now, shall I just source a set of carbs or is the problem not with the carbs, is any one local to me, Blackpool, with mechanical knowledge of a storm!!!!!!!!!!!!!!!!

[tony.mon]

Why not just get it set up properly on a dyno?
If there's anything wrong with the carbs it'll show up, and for about the same money as you'll need to spend buying a spare set of carbs your engine will be properly set up.

[graham1963]

got my bike back yesterday, all sorted, runs well, don't know what he's done but its right, thanks for all your replies/ideas, Graham.

[tony.mon]

I hate a mystery, me, and have to know what cured the problem.
So could you ask him what he did?
Isn't it on your itemised bill?

[graham1963]

Only charged me 20 quid labour, the rest was on an MOT, standard air filter, new plugs, i know he ended up putting the larger jets back in that were in it when i bought the storm, so dont really know if its a combination of these or something thats just righted itself, all i know is that i'm back on the road again