TPS/Carb jetting/Cans!!

[VTRDark]

Sorry to hear you have a bit of a shitter of a day griff. Getting a tug on top of all that as well

The first thing that rings bells with me is why an initial run when you arrived. The change of filter was obviously going to effect things. And a standard filter chucked back in but still no needles or mains changed yet. Then all of a sudden it's we can't use the BMC lets stick with stock. those two runs IMO where pointless and just making money for them.

The guy is sort of right about the free flowing air filters but not totally, yes the VTR airbox is extremely sensitive to tuning and does not like being messed with, but that does not mean that it's not possible. Plenty of people run a K&N or other aftermarket filter's it just means that it's not a straight swap and it takes some dyno time to get it dialled in accordingly. Seb is correct in what he's saying. That is the whole point of a dyno. Otherwise you may as well stuck with the stock settings which is near enough what you are now running with the exception of the needles.

So once it's decided which filter to use he has then changed the mains and put the needles in, and then done another run. IMO what should have been done is to change the needles, mains and filter first of all and then done a run. There are example base settings with the FP instructions that could be used for a starting point. Then go from there. Pete is also right and the larger main should be in the rear to help keep it cool. Surley even logic should tell him that as the larger one was in the rear to begin with.

With regards to the drilling of the carbs, I don't know why he has not bothered with that. Maybe it's something he did not feel confident with. Yes once it's done you can't go back, but if the worst comes to the worst then 2nd hand carbs are on ebay all the time averaging £50. He could have given it a go and then used the dyno to get the carbs dialled in accordingly. I don't know of anyone that has taken this route but I'm sure FP know what they are doing and the reasoning behind it. Just seems a bit of a cop out to me.

Saying that though, with the dyno read outs you have it's giving out good bhp but that's not everything. Looking at the last chart (4th gear HP & Tq) the torque curve is reasonably straight. There's a couple of little dips, one at 60 and then goes back up at 70 to 80 then there another little stutter at 90. But overall pretty good.

The A/F reading is a little on the lean side at the start then tails off at 5.5. It's not totally sh1t and 14 is optimal performance but these bike like to run on the rich side a bit so would be better nearer the dashed line on the readout. This would also explain the hesitation. I think to mixture is to weak with only 2 turns with the 45 pilots. With 48's you would find about 2.5 turns out would be about right. And why is the mixture the same for front and rear carb when they have different mains. TBH I would expect a dyno technician to adjust the mixture by ear which is the more professional way of doing it. Also this would not take up time having to remove carbs to adjust again. On the top end mains the A/F run back onto the lean side which makes sense as he gone smaller than standard with one of the mains.

The other two charts are little more all over the place and I can't work out which one is of importance so I just following the last one. I'm wondering whether he has just done it in a way to give you good max BHP and not specifically to the A/F throughout the whole range.

In all honesty and by going by the last readout it's not all bad and a very reasonable readout but could be improved a bit. I'm a bit myth'd to why he just did not dial it in with the BMC, K&N, standard or whatever filter you give him to use, that is the whole point of using a dyno. And why he put the larger in the front just makes no sense especially as with the standard Honda setting the larger goes in the rear. Did he check the emulsion tubes to make sure they have not been changed or been put back the wrong way around in the past at all.

If I had my own dyno I would start with getting the mains that gave best performance with a slightly larger one in the rear, then move onto the needles and then the pilot jet/mixture screws.

OK I have rambled on a bit there and I don't want to make you feel worse, but that''s my opinion. I would see how you get on with it and maybe go back to them in a few days next week or whatever and tell them your not entirely happy with the way it's running and get them to richen it up a tad, specifically the lower end if your getting that lean hesitancy. What you want to achieve is as straight a line as possible along the dashed line on the A/f scale. If it's going to tail off at all it's better to go on the slightly rich side than lean so towards the 12.

(:-})

[VTRDark]

but even on their own recommendations it says use stock or equivalent air filter.

I would take that with a pinch of salt Lee as equivalent is a broad range. So what they are saying in the top of the instructions there is just a general thing.

On the kit below that which is exactly the same except for the drill bits it says under the main jets supplied section on the left with a BMC or K&N increase the mains by 2 sizes from above suggestions. But considering your increasing air flow by drilling out the main air jets then maybe a higher flow filter is not necessary with this particular kit. Even FP recommended the BMC and used to sell them on their site. That could have just been sales talk though

But at the end of the day it's like Seb said, it's just a case of getting the appropriate balance of air and fuel ratio. It don't matter what filter is used, it's just a case of getting it dialled in. It just might take a few more runs to get it there. You could gut your airbox if you wanted and get that dialled in.

Out of curiosity Griff how many runs in total did he do on the machine.

(:-})

[Griff1977]

108 is good, but the fluffing low down will piss you off the A/F line looks good as well

dont understand what the BMC is giving such a bad outcome, as I just dropped mine in and it got better..........are you sure its not the Race version

Cheers Al, twas the street BMC. It was horrible to ride - the dyno showed the A/F with the BMC in and it was so so lean - I was offered the graphs but I said no as I never wanted to see them - I might get one for comedy!! Griff

[Griff1977]

Harsh! But true Seb

I must admit its been a while since I,ve done any jetting on a Firestorm but I thought the bigger main jet was supposed to go in the rear ? As the rear pot runs slightly hotter you richer it up a tad to make it run cooler.

Pete.l

Pete, yep you are right, and we even spoke about it and the reason for this (cooling).

I need to ask him again about this. We balanced carbs afterwards and they were obviously a bit out.

Griff

[Griff1977]

Well you know his settings now so you could try your own now and always revert back to his until you get it sorted some place else

stick the BMC back in,

try 48 pilots on both,

Try the Needles adjusting one clip richer as the bmc will flow more air

go up one size on the mains

and try the A/F at 2 on the front and 2 and a quarter on the rear

See how that feels, and keep making little changes from there....

you have his base settings to go back to if nothing else.


I have some 48 pilots you can have for free mate (send pm with address)


play about for abit then take it to a dyno for a power run

Cheers Seb. PM sent, ta.

And at least I have seen the techniques of accessing the carbs easier (tilting to one side to get to bottom), and where the components are.

The bike is completely rideable, just, as Al said, the low end bogging will start to piss me off.

Laters, Griff

[Griff1977]

Sorry to hear you have a bit of a shitter of a day griff. Getting a tug on top of all that as well

The first thing that rings bells with me is why an initial run when you arrived. The change of filter was obviously going to effect things. And a standard filter chucked back in but still no needles or mains changed yet. Then all of a sudden it's we can't use the BMC lets stick with stock. those two runs IMO where pointless and just making money for them.

The guy is sort of right about the free flowing air filters but not totally, yes the VTR airbox is extremely sensitive to tuning and does not like being messed with, but that does not mean that it's not possible. Plenty of people run a K&N or other aftermarket filter's it just means that it's not a straight swap and it takes some dyno time to get it dialled in accordingly. Seb is correct in what he's saying. That is the whole point of a dyno. Otherwise you may as well stuck with the stock settings which is near enough what you are now running with the exception of the needles.

So once it's decided which filter to use he has then changed the mains and put the needles in, and then done another run. IMO what should have been done is to change the needles, mains and filter first of all and then done a run. There are example base settings with the FP instructions that could be used for a starting point. Then go from there. Pete is also right and the larger main should be in the rear to help keep it cool. Surley even logic should tell him that as the larger one was in the rear to begin with.

With regards to the drilling of the carbs, I don't know why he has not bothered with that. Maybe it's something he did not feel confident with. Yes once it's done you can't go back, but if the worst comes to the worst then 2nd hand carbs are on ebay all the time averaging £50. He could have given it a go and then used the dyno to get the carbs dialled in accordingly. I don't know of anyone that has taken this route but I'm sure FP know what they are doing and the reasoning behind it. Just seems a bit of a cop out to me.

Saying that though, with the dyno read outs you have it's giving out good bhp but that's not everything. Looking at the last chart (4th gear HP & Tq) the torque curve is reasonably straight. There's a couple of little dips, one at 60 and then goes back up at 70 to 80 then there another little stutter at 90. But overall pretty good.

The A/F reading is a little on the lean side at the start then tails off at 5.5. It's not totally sh1t and 14 is optimal performance but these bike like to run on the rich side a bit so would be better nearer the dashed line on the readout. This would also explain the hesitation. I think to mixture is to weak with only 2 turns with the 45 pilots. With 48's you would find about 2.5 turns out would be about right. And why is the mixture the same for front and rear carb when they have different mains. TBH I would expect a dyno technician to adjust the mixture by ear which is the more professional way of doing it. Also this would not take up time having to remove carbs to adjust again. On the top end mains the A/F run back onto the lean side which makes sense as he gone smaller than standard with one of the mains.

The other two charts are little more all over the place and I can't work out which one is of importance so I just following the last one. I'm wondering whether he has just done it in a way to give you good max BHP and not specifically to the A/F throughout the whole range.

In all honesty and by going by the last readout it's not all bad and a very reasonable readout but could be improved a bit. I'm a bit myth'd to why he just did not dial it in with the BMC, K&N, standard or whatever filter you give him to use, that is the whole point of using a dyno. And why he put the larger in the front just makes no sense especially as with the standard Honda setting the larger goes in the rear. Did he check the emulsion tubes to make sure they have not been changed or been put back the wrong way around in the past at all.

If I had my own dyno I would start with getting the mains that gave best performance with a slightly larger one in the rear, then move onto the needles and then the pilot jet/mixture screws.

OK I have rambled on a bit there and I don't want to make you feel worse, but that''s my opinion. I would see how you get on with it and maybe go back to them in a few days next week or whatever and tell them your not entirely happy with the way it's running and get them to richen it up a tad, specifically the lower end if your getting that lean hesitancy. What you want to achieve is as straight a line as possible along the dashed line on the A/f scale. If it's going to tail off at all it's better to go on the slightly rich side than lean so towards the 12.

(:-})

Carl, wow, thanks for your interest!! Before I forget, in your 2nd response you ask how many runs we did - I lost count, prob about 6 in the end; he only 'charged' for 1 and then 3.5 hrs labour, so fair enough I guess, but I didnt realise it would take that much time!! Maybe I should've got the carbs basically set and then gone to him for tweaking!?

Or at least, I was hoping to set the carbs with the kit settings and then adjust from there. This didn't happen. The kit was just dipped into after the first few runs, even then, with the standard air filter.

Interesting what you say about generally the VTR liking rich tendensees, so if its going to sit just above or below, best below - because yes a few of my traces show slightly above (lean).

Ahhhh, if I had a couple of free days soon, then I'd attack it myself, spend time and effort, continuity etc. But thats me now after my week off, back to my Yorkshire-Wales commuting routine.

Ill treat it as an on going project, and an experience.

Though, the chap did offer to do the MOT for trade (£20) and he will tweak the mixture again then if I think it needs? MOT expires next month, so I have a while to think.

Regards, Griff

[Pete.L]

Sounds like a plan. Get a cheep MOT and keep on his good side and tell him it's bogging at low revs. He might have just wanted a brake from it and was having an off day.
My only other thoughts would be how many Storms has he done before? If he hasn't done that many he might not be fully conversant with their foibles.
Sorry you're disappointed with the outcome Griff but now you've entered the tuning phase you'll be forever tweaking now you've seen it done

Pete.l

[AMCQ46]

I think pete has a good point about how familiar your dyno man is about storms, or carbed bikes in general as I think too many of these places are all focused on remapping injected bikes.

Having a 2nd look at the A/F line now I am less jet lagged I agree with Carl, it's too lean at the bottom, and even after that it would benifit from a bit of a richening to give you better drivability in the 5 to 6K range.

[VTRDark]

but now you've entered the tuning phase you'll be forever tweaking

Your know it's true , I find myself tweaking things just because of a change in the weather. I really must get a flow commander.

(:-})

[leevtr]

but now you've entered the tuning phase you'll be forever tweaking

Your know it's true , I find myself tweaking things just because of a change in the weather. I really must get a flow commander.
(:-})

Don't see why. Mine hasn't been touched since. Running fine as the dyno showed.

[seb421]

but now you've entered the tuning phase you'll be forever tweaking

Your know it's true , I find myself tweaking things just because of a change in the weather. I really must get a flow commander.
(:-})

Don't see why. Mine hasn't been touched since. Running fine as the dyno showed.

If it's jetted in summer it can make a difference in winter with the colder denser air flow causing it to run leaner than it did when optimally jetted for the summer

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[VTRDark]

Nor do I mate. If I didn't know you I would say. Well, you obviously haven't a clue or and understanding to how carbs operate and don't have a feel for it. But I know that's not true cause I know you have a lot of experience riding and have good feel for things and push bikes to their limits, so it don't make sense to me.

At the end of the day it's fact that carbs are affected by all sorts including the weather conditions altitude etc hence the reason you have companies making things like flo commanders to help with little tweaks to compensate for this. As air temperature increases (summer) it's less dense, the air particles are not as compact, so there would be less air being fed into the mix which makes things run richer and then when the temp goes down (Winter) the opposite has an affect as the air particles are more dense, which adds more air into the mix which will then make things run more lean.

Maybe the dyo tech that done Griff'ss bike has taken this into consideration and set it up slightly on the lean side, realising that Summer is around the corner and it will richen up a tad.

You could be riding around on a hot Summers day and the bike runs perfect and then in the evening as it gets colder the bike could lean off a bit and not run as well as it did earlier on in the day. Depending on what you A/F reading is set at. This is why it's best have the A/F along the dashed line as this is an intermediate and will give you the best off both worlds as it fluctuates either side of the line as the weather changes.

The same with altitude as you go higher above sea level, something like 5000ft for drastic changes the air gets less dense and richen's the mix up hence carburetted bikes will bog down as you ride through the mountains.

(:-})

[leevtr]

Well I don't think the seasons make enough of a difference, otherwise manufacturers wouldn't be able to find an across the board setting to sell their bikes. My old storm I had for 4 years, had it dynojetted, never touched it again. I do know that the heat did affect the top end, my I could only tell by my top speed at the end of a lap of the ring, couldn't feel it day to day.

I looked at the dynojet settings this morning on the fitting guide. Admittedly this is with their needles, and might not work with FPJ, but I have used 180 jets, and AF screw 2 turns out. The result below. The red line is my old storm, which, at the time of the dyno run, had 30-odd thousand miles.The blue is my current bike, about 12000 at the time. Both were standard DJ settings, no dyno time ( other than these power runs where no adjustments were made. ) These runs were on the same dyno, by the same operator, about 7 years apart. Looking at Griffs output of 110bhp, and bearing in mind he isnt quite happy with the way the bike runs, mine doesn't look that optimistic after all.

[leevtr]

Nor do I mate. If I didn't know you I would say. Well, you obviously haven't a clue or and understanding to how carbs operate and don't have a feel for it. But I know that's not true cause I know you have a lot of experience riding and have good feel for things and push bikes to their limits, so it don't make sense to me.

At the end of the day it's fact that carbs are affected by all sorts including the weather conditions altitude etc hence the reason you have companies making things like flo commanders to help with little tweaks to compensate for this. As air temperature increases (summer) it's less dense, the air particles are not as compact, so there would be less air being fed into the mix which makes things run richer and then when the temp goes down (Winter) the opposite has an affect as the air particles are more dense, which adds more air into the mix which will then make things run more lean.

Maybe the dyo tech that done Griff'ss bike has taken this into consideration and set it up slightly on the lean side, realising that Summer is around the corner and it will richen up a tad.

You could be riding around on a hot Summers day and the bike runs perfect and then in the evening as it gets colder the bike could lean off a bit and not run as well as it did earlier on in the day. Depending on what you A/F reading is set at. This is why it's best have the A/F along the dashed line as this is an intermediate and will give you the best off both worlds as it fluctuates either side of the line as the weather changes.

The same with altitude as you go higher above sea level, something like 5000ft for drastic changes the air gets less dense and richen's the mix up hence carburetted bikes will bog down as you ride through the mountains.

(:-})

I think you flatter my riding mate. I deffo don't push the bloody thing to its limits, I wish I were that good/brave/stupid...delete as applicable

[seb421]

Well I don't think the seasons make enough of a difference, otherwise manufacturers wouldn't be able to find an across the board setting to sell their bikes. My old storm I had for 4 years, had it dynojetted, never touched it again. I do know that the heat did affect the top end, my I could only tell by my top speed at the end of a lap of the ring, couldn't feel it day to day.

I looked at the dynojet settings this morning on the fitting guide. Admittedly this is with their needles, and might not work with FPJ, but I have used 180 jets, and AF screw 2 turns out. The result below. The red line is my old storm, which, at the time of the dyno run, had 30-odd thousand miles.The blue is my current bike, about 12000 at the time. Both were standard DJ settings, no dyno time ( other than these power runs where no adjustments were made. ) These runs were on the same dyno, by the same operator, about 7 years apart. Looking at Griffs output of 110bhp, and bearing in mind he isnt quite happy with the way the bike runs, mine doesn't look that optimistic after all.

Ones running lean, and ones running rich? You must have felt that surley?

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