solorider wrote:i have just bought a firestorm,it is a 2000 model,the bike has art cans on it and i have a running pronblem,while youe are cruising at constan throttle the bike backfires through the air filter and seems to hold back,the bike does this upto 100mph,it seems ok usingt full throttle and the exhaust pos on the over run,i dont know the mileage of the engine as it was replaced with a second hand unit at 46k miles,the bike has 56k miles at the moment
the "holding" back problem only seems to happen when the engine is hot,and only at constant throttle,open the bike and it goes very well,it is like fuel starvation but not at full throttle which is odd
The "holding back" is more likely to be because it is slightly lean in the mid range. K&N air filters on std carbs are renowned for giving a flat spot or holding back on steady throttle around the 3.5-4.5k.
Try placing a 0.4-0.6mm thick washer under the needles to raise them a bit. I know your plugs are tanned but that's just a general indication of how the bike is running and not a complete diagnostic of how the mixture is at specific rpms.
Pete.l
My new ride is a bit of a Howler and I love to make her Squeal
an update ref my running problems,decided to remove the rads and fill with fresh antifreeze,when i un done the top hose there was no water in there,the rad was only a quarter full,might explain why no water came out when i took the water pipes off the carbs,reservoir was full,bike warmed up normally looking at the gauge and never overheated,no signs of any coolant loss,im thinking it could be down to fuel evaporation ,opening the throttle allows a quicker flow of fuel hence why it didnt happen on full throttle and the smell of petrol,it being evapotated.i havnt ridden the bike as i have just finished it so hopefully this will cure the problem,what do you think?
changed the cct,s and there was nothing wrong with them
bike sounds lovely with the blue flame cans fitted
well ive solved my running problem,it was believe it or not lack of water in the rad caused by a leaking rad! it only leaked when hot and it only seaped out,i only found out after noticing the rad nearly empty and in the process of changing the antifreeze,after giving the bike a good run there was a smell of coolant.only after a good look did i notice that the fan was wet,removed the fan and found that the fan had tried cutting through the rad,what was happening was as the engine got hot it got hotter in the v so causing the fuel to vapourise,hence why the problem only happened when hot,the bike did not over heat or show signs of over heating,the header tank had plenty of coolant in it,weired thing is there was no signs of a leak when i took the rad off to make sure all the fluid was removed.
im going to modify the air duct with a removable panel so i can in the future top up the coolant or check the level without removing the fairing
Stratman wrote:You shouldn't top up the coolant direct into the radiator but use the reservoir instead and you don't need to remove the fairing.
yes normally but in this case the water level in the reservoir was ok,but the water level in the rad was nearly empty,cant understand why the reservoir level didnt drop as it should have but it didnt
I'm pleased too hear you found out what the problem was Solo An interesting one to say the least
I have a feeling the Jap market engine was restricted on the inlet manifolds, and if I remember correctly (I could be totally wrong here) had different carbs. If your original carbs were fitted to your replacement engine, and the restrictor plates from the inlet manifolds were removed then all of the above is not going to apply to your bike, providing your bike was a UK spec model in the first place of course
I know USA and Australian models suffer the restricted manifold inlet, but do all UK bikes not have them? I'm getting a jet kit and air filter fitted next service (in the next week or so) and am wondering if they need to whip out a restrictor on mine while they're at it.
Kitch
do you have the correct manual for your model. If you do I would compair the numbers on each of the jets. If they are the same as the uk spec I would rip those beasties out of the inlet and try to get a few more ponies out of the old girl
You get new mains and needle with a K&N kit so the only ones which you might need to check on is the slow circuit.
Pete.l
My new ride is a bit of a Howler and I love to make her Squeal
sirch345 wrote:I'm pleased too hear you found out what the problem was Solo An interesting one to say the least
I have a feeling the Jap market engine was restricted on the inlet manifolds, and if I remember correctly (I could be totally wrong here) had different carbs. If your original carbs were fitted to your replacement engine, and the restrictor plates from the inlet manifolds were removed then all of the above is not going to apply to your bike, providing your bike was a UK spec model in the first place of course
Chris.
as far as i can tell the original carbs were used,there is no restrictor under the manifolds,luckily.the bike was a uk model from new,the engine was changed due to a cct faliure
Pete.L wrote:
You get new mains and needle with a K&N kit so the only ones which you might need to check on is the slow circuit.
Pete.l
my bike has a k&n filter and has standard jetting.how can k&n know what jets you require or even needles without knowing what has been done to the bike?
Pete.L wrote:
You get new mains and needle with a K&N kit so the only ones which you might need to check on is the slow circuit.
Pete.l
my bike has a k&n filter and has standard jetting.how can k&n know what jets you require or even needles without knowing what has been done to the bike?
Well obviously they can't know exactly what jets you need or what settings the piolet or needles need to be on. That's why you get several jets in the kit with base settings to get you started. And it's also why there are so many tuners out there making a shed load of dosh cause it's not something you can do very well in your own garage with out the proper kit.
Pete.l
My new ride is a bit of a Howler and I love to make her Squeal
An interesting one to say the least 
