running lumpy/jerky low down unless choke out

[mbucko]

right after getting the bike out today i decided ive had enough of the low down lumpy almost rocking back and forth unless i gun it or pull the choke out and that seems to make it better which to me (car mechanic) so would this suggest its just the mixture running lean now when i bought it it does have art cans kn filter and stage 1 dyno kit all done about 3 years ago (only done about 500 mile since) now a do you think it is just the mixture and i should mess with it or leave it and send it into the local dyno centre (please bear in mind i hate carbs with a passion i was educated with a obd socket and injectors)but on the other hand like every body at the mo im skint your help would be greatfully welcomed

[darkember]

OK for starters to check if you are running too lean or rich is to get the bike warmed up then visually check the state of the plugs. Front plug should be digestive biscuit light tan & rear should be the same but slightly darker as it is jetted to run slightly richer thus cooler. This is from a standard setup without any fancy stages or filters, the only addon are a set of Scorpion cans without baffles. Note these bikes will get lumpier the more high level tuning parts you add. I used to have a K&N filter but soon went back to standard & I can get it better still if I fit the DB killers but miss the sound.

[benny hedges]

airleaks at the carb rubbers and or split & perished vc hoses would be my first port of call.
dont adjust anything until youve ruled these out.

[Wicky]

With the cans and filter the jetting will need setting up for optimum performance on a dyno - they're in combination not a plug'n'play tuning mod. You could in the meantime try installing a normal Honda airfilter to see if that improves things as Storm is sensitive to airbox/breathing mods.

See dyno charts in Workshop subsection

[8541Hawk]

Without going into why I don't like that carb set up I will say that you have a pilot jet issue.
Did the bike sit for a long period of time?

You have two options right now, first try some fuel system cleaner and hope it cleans the jets out.
Or pull them and either clean or replace them.

If you have ever looked through a pilot jet you would see it starts out as 1 small hole then splits into 3 smaller hole....so yes they are tiny.
This is why I usually just replace them as one I figure what my time is worth it is just cheaper to swap them out.

[VTRDark]

Or pull them and either clean or replace them.

(nodding head) yes I think so. Get to know your carbs. Pull them off, give them a good blast through with some carb cleaning spray and you can verify exactly what the set up is. What size mains, pilot etc, unless ofcourse you fitted the kit Has it still got the original diaphram springs or is it an imported US kit with dynojet springs Has it had the extra lift holes drilled out on the slides. These bikes don't like the extra lift hole that dynojet kits recommends.

By removing tha carbs it also gives you the chance to look everything over thoroughly and you can check the carb inlet rubbers properly for an major deterioration that could cause air leaks. You could also adjust the TPS to 500 which helps with the low speed steady state cruise. And while you there and the carbs are off, you might as well fit some vacuum pipe on the front take off for ease of use when it comes to carb balancing if it's not been done already.

There's no need to hate these carbs, they are very basic and simple to play with. And on the VTR they so fooking big it's like working on car carbs. But because they are so big they are very sensitive to any changes from a standard set up particularly aftermarket filters.

Yes you could just take it to a dyno tech to do the work but it will cost you a small fortune as most of them don't like pulling carbs when it's easier money for them to work with FI. Surly you have ask yourself, do you trust them to know what they are dong, are they going to do a proper job. Do they know these bikes. As a car mechanic I would have thought you would find it difficult to trust anyone else. Best to do the work yourself and then just have a dyno run to verify that your changes work. The dyno is only a tool Its whether you do the work then go and use the tool or give it to someone else to do the work and use the tool.

Plenty of info info in the carb thread in my signature. You may want to have a browse through. And if you have any questions then ask away, we're here to help.

(:-})

[darkember]

Do remember if you replace the main jets check the sizes as each carb will have a different size main jet remembering to refit the correct jet to the correct carb. Without searching I believe the larger one fits to the rear carb. Someone here will correct me if I'm mistaken.

[8541Hawk]

The bits that tend to get mixed up if both carbs are torn down and the parts are not kept separate are the main jets, needles and emulsion tubes.

Get these mixed up front to rear and you will have some odd issues.

[VTRDark]

Talking about needles. Interestingly enough the standard needles are different lengths but have different part numbers to ones in the states. Not sure if the profile is different. IIRC there's only a couple thou difference between the two.

I believe the dynojet needles are exactly the same, though they have possibly worn into each carb slightly different so best to not mix them up.

(:-})

[Smokinjoe73]

To my experience, few mechanics even want to touch carbs. And replacing them is nuts. (for now)

If pulling the choke helps then its running lean (choke enriches the circuit)

If the bike was stored, you should assume the fuel in the tank is finished (unuseable by bike). Modern fuel has a really short shelf life. DRAIN THE TANK. Its way easy for the problems it will solve. For all you know you are running the bike on half water. A drain and refill could fix everything with some fuel system cleaner. Drain it dry though, not syphon but petcock and upsidedown shake.

The fuel in the carbs (if not drained) turned to varnish and needs to be cleaned out. Not a huge deal.

For sure 8541 is right about the slow speed/main jets. So get over your waif-like fear of carbs. The last thing you need is some nut messing with your carbs. You can just carefully disassemble and clean them.

Take a ton of pics or video the procedure to help later freak outs. ONLY ever take ONE carb apart at a time and use a foil turkey pan to catch small bits. This prevents A) Losing small parts and 2) mixing front to back exclusive parts.

Plus you can always scamper back on here to ask questions. Isnt a dyno run a big chunk of coin over there too?

[VTRDark]

Plus you can always scamper back on here to ask questions. Isnt a dyno run a big chunk of coin over there too?

Indeed it can be. You can sometimes get a dyno run for £10 a run, that's about $15 to you. But if you going to pay the dyno tech to start playing with the carbs and yes, it going to cost big bucks, especially as, like you say, they don't like working with carbs.

Good call on the old fuel, though our fuel is a lot better quality than you get but it still deteriorates with time.

(:-})

[mbucko]

Right I've cleaned the tank and put fresh fuel the put back to stock air filter is next so I've ordered one and will let you know thanks all comments taken on boad

[Smokinjoe73]

Yeah well why climb mount everest if there is a tram to the top. Even if you scour your carbs, the bad fuel would foul everything up right away.

Dont make me tell my story of swapping a motor only to find out I got a tank of diesel fuel causing tons of smoke. (gas station in middle of nowhere with no humans working there).

I was imagining 2-300 for a dyno run (dollars)

[mbucko]

Well finally had time tonight to take out the k&n filter and put a new stock air filter back in and its made the world of differance pretty much got rid of all the low down jerky rocking thanks all for the in put

[leevtr]

I was just going to say get rid and you already have...good job !! I really dont know why people bother with them on Storms, not worth the hassle for bugger all gain.