Although I've already checked it, it's niggling me that the lower seat might be restricting the air a bit too. I'm going to have to do a run with the old seat, just to confirm the new one isn't giving me a falsely rich MJ. The thing is, apart from that low splutter, it feels great; well fast enough, so I'm not stressed about this. And although we're calling both Sunday's results 12PS, last Sunday was 11.16, and this Sunday was 12.13, so there is a 1PS improvement by downjetting (or giving it more air?). As you say; MJ, temps, plug. A few days away from it and a decent bash at it next time, concentrating on that, not the numbers.
No MD or 0-60 temps till the weekend, and only if weather permits, but some respectable dual carriageway speeds, plugs and temps to record this morning. These are with the old seat back on; I do think the race seat is, ironically, a restriction, so I'm going to leave old seat on until weekend to do MD and 0-60 then decide whether to jet with or without it. Anyway that's not important; here's some numbers:
48/160 & 135MJ – old seat: Max speed (3km dual carriageway only) = 110kph = 68mph = 7250rpm = 144ºC
That seat really might be an issue. The air doesnt need to be very restricted to be a problem. Could it be closing the air hole as you sit on it?
72mph on GPS (probably over 80mph on a Vespa speedo) is plenty and if you feel it will go a bit faster then that's about it for speed. The 132 MJ does look like it will do for now. With it fully hot over 140C, I don't think it will splutter at low rpm. If it is we can fix that. Ride it exactly like this for a few weeks and let it settle down. Ride it hard and ride it slow and cruising and report back any issues as you find them. I think the next MD will be a bit better
The 132 plug is looking much better. Once it's been running for a while it will look better.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
The height above the hole with the new seat is about 1" instead of 2"ish - by eye. The old seat has a square front giving a gap though (where the helmet hook is), and the new seat follows the shape of the frame much more closely all around its edge; I think it is here that the restriction is - actual air flowing into the area under the seat. The actual hole in the hinge in the new seat is smaller than the old seat too, but still about the same size as the hole in the frame. My theory, for what it's worth, is that with the air restriction of the new seat it would need downjetting more to get the 1:13ish (haven't checked the big word*) ratio, so that would mean less fuel for less air, which is losing the nice free-flowing carb, inlet, casings, barrel and exhaust of the new engine; so a lower performance than is achievable by unrestricting air under seat again - same ratio, but bigger volumes! Before the carb mods we couldn't get enough fuel for the air (155MJ); now those are done, the seat seems to have gone to the opposite, where we can't get enough air for the fuel (135MJ). Yes, I'll happily just ride it for a few weeks and make just observations. The other point there is that will include a couple of runs up and over the Moors, which will give me a better idea of how it is coping with what I wanted it for, which is pulling me and my weekend bag up the big, windy hills and lanes without changing down so much or plodding. it is that performance, rather than the top speed where I'll appreciate seeing the improvement - my everyday or usual excursion riding, not top performance, which I'll rarely need. I know good jetting here is needed to set it up right though. Going to check my Pilot again too.
72MPH GPS is well off my speedo, which goes up to 120KPH (75MPH), but we know the GPS is right and the Vespa Speedos are low. I wasn't strangling the last out of it to get 72MPH; my nads gave up before the engine did - I wasn't even tucked in. I do have in mind the "lean in Winter, thrash it in Summer" approach, so there's maybe another downjet tweak if needed later, but that can wait till I've had some good long rides.
The next MD will be better, I'm sure too; but it's only a number to prove a known; I'm already well happy - it's doing more than I need. I'd like to see a curve without that first dip though.
When you use that seat, I think the best idea will be to take off the rubber tube and put a filter on the carb box.
Get some miles on it and see how easy the touring is now
Just for the record, can you do a sound recording of how it is on an MD like run in 3rd?
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I've found these Ramair filters; I imagine that's the sort of thing you mean, and probably the longer of the two – there's a 70mm and a 117mm long option, Ø58mm (I measured a spare box, but I'll check mine too), £19. I reckon I'll concentrate on getting the jetting right with the old seat for now, and maybe play with new seat, filter and rejetting later if I get the urge; it isn't important, I just liked the look of it, not particularly comfortable or practical really - though I liked being a bit lower. Hilly MILES, and some fast runs, is what's needed now; and some MD-type WAVs (and graphs) soon, without the stutter this time. Was it clear that in my previous weekend's posts, I combined the WAV (sound recording) with the graph to make a movie? So you're looking at the dyno and hearing the WAV at the same time? If not I'll do it differently, or make it clearer next time.
Hi guys... I see youre still not quite there as yet..... ive not had much chance to catch up so forgive me if i repeat something thays already been said..and ive not been able to listen to any wavs either....and ive not read everything..... Naughty i.know..but.....
You finally thought about the sports seat..!!!.my first impression is the seat is something not to be over looked...check the air flow...if its blocked/smaller, then it will cause a problem....similar symptoms....feels richer!? A friend of mine had similar problems...running crap on the way home from a rally..turned out he had a jumper packed under his seat, Blocking the air supply. removed jumper, no more prob
I dont know if youre swapping different makes of jets around....i told you before rigjt!? In my experience, different brands are slightly different sizes.....changing from a INC 140 to a BGM 138 for eg is not necessarily the step down youd expect.... Keep to one brand of sets, disregard the actual number/size of the jet..jet by feel, MD runs etc, not by the number stamped on the side of the jet. I forgot what else was said now....i cant see the thread as im typing.
The 3500rpm range....thats around where the atomizer changes things. Of course you need your jetting close.
Did u try with your side panel off and with no rubber hose/air box top off? Or put your old seat back on for a test.
Seems your close
Ill be keeping an eye on this thread when i can....hope you can get it sorted before i get back from here, (i'm virtually in Bhutan)
Hi mate; good to hear from you! I'll reply at length because it serves as a bit of a summary of progress too: A lot of what you say is similar to conclusions we have drawn as I've progressed, but if you're reading further back, you might have missed the most recent discoveries/improvements. I'll go through yours in order it's written: Yes I'm pretty sure the sports seat was restricting the air, making the mix richer, so when I was finding optimum MJ with that seat I was actually jetting for reduced air volume flow, not leaner mix. For now I'm back to jetting with old seat, and getting much better speeds and temperatures, and these are the settings I'll do my next MD (with a WAV sound recording) and 0-60 on (or perhaps one MJ smaller if I do them on a mild day). I currently have 48/160 & 132, and on a 3km WOT run I got GPS 116kmh/72mph and 146ºC and a good plug. - That's pretty close now. The two main things that made finding that point tricky were changing the seat mid-way through, and the temperature variations we've been having over the period of jetting since Christmas, where it's been from -2ºC to 12ºC on test days over that period (wind, pressure etc., too, but temp is the one I noticed particularly). If you include the MJ brands as another unwanted variable; these are the things I've leant to avoid next time – to keep as much as possible the same and just change one thing. I did try the seat without the hose with the side panel on, but not at WOT really, and probably still too rich anyway to affect it; I didn't notice much difference, but the jetting since has pretty much confirmed the seat, and if/when I go back to using it, I'll rejet with a filter on the carb box. It has occurred to me that if I want to swap between Touring seat & big rack, and Summer stripped-down & seat without rejetting then the filter on the carb box simplifies the job, and possibly is a performance increase too, if it gives me an increased air volume flow; I need a bit more knowledge here - I was looking at these Ramair filters yesterday, which I think are the sort of thing I need. I'm not sure what difference using that air (under cowl) has; whether it is dirtier or hotter - I imagine not, because it's blown around fairly efficiently by the fly/fan, or if it's pretty hot and stagnant outside of the head-cowl under the side-panel; I don't yet know what's fact and what's forum myth on the subject. Now I'm under 140MJ I'm back to all INC MJs; I agree that swapping brands might give some unexpected results. Keeping to one brand over the range from mid-150s (before carb drilling) to low-130s was not possible, but I agree would be ideal. It has opened my eyes to what you chaps have been saying about different makes though; I've got INC, Spaco, BGM, unbranded, and home-drilled in my set for the full range, so it all needs a bit of a sort-out; my Pilots aren't all INC either. Ahh, the 3500 stutter! - Now I've got my WOT speed/temp sorted (or one MJ tweak short of sorted, maybe); this stutter is my main irritation. It may be gone now – it certainly was less noticeable after my last downjetting. I'm going to do a full-range acceleration in 3rd to get a WAV just for that to see if it's gone, probably later today; and on the weekend I'll do MDs and 0-60s, which will hopefully show that first hump gone, a cleaner engine sound, and better low-end acceleration - as well as a better PS. I've been thinking ahead to the atomiser, and thinking that It's say 2500 to 8500 for me, and 6 rows of holes, so probably, if a bit of a simplification, dividable to identify a rev-range problem, and that this 3500 splutter could probably be used to focus on the top row, but I've sort of been expecting that to come up after I've got my MJ right, and if there's any sign of it remaining, or the other -'double-hump' nearer the top-end, lower down the atomiser, which I think I recall you sorting with your MD dynos. These dynos I'm getting now are not bothering me too much at present; I'm still downjetting to optimum, and you made dramatic improvements on your first ones, and I'm sure I can make good improvements in my numbers, but it's the wonky shape I was getting together with this 3500 stutter that's been bugging me. We've improved it already (numbers and shape), and hopefully close to losing it and getting better numbers – stay tuned! When I have the MDs that I'm settling on for now; maybe this weekend, I'll email you some WAVs to listen to or play with for when you return; I'm sure you're not too bothered whilst adventurising on the India/Bhutan border! Hope you're having fun, not much is happening here, except Henri has broken the Internet and has started a coup; just normal day-to-day business........
As it's still holidays there: I took the shell off my racing snail to make it go faster, but it's made it more sluggish!!!!
I've got two clean runs without the 3500 stutter, so probably worth sharing; I'll type as they upload:
48/160 & 132, max recorded temp 119ºC, no GPS speedo because I was recording WAVs, but I can extrapolate from isolated 3rd gear part of WAV when I've finished playing – I was off my Veglia speedo, which goes up to 120kph, but only for a short run in 4th between dual carriageway junctions.
Slow 1st and 2nd, then full rev-range 3rd – similar to an MD run, but cut short to avoid joining dual carriageway – it's too short for the MD, but I'm concentrating on the 3500 in 3rd here:
Fast through all gears, including joining dual carriageway in 4th(ignore the hesitation in 4th here, at about 40 seconds; I was easing off to join road, then held it at WOT afterwards), and short run at WOT before slowing for off-ramp:
MD from isolated 3rd gear of above WAV – not really a proper MD because started too high in revs:
^^^press PLAY► on this MP4 to hear the isolated 3rd gear WAV for this dyno.
Now, I'll be the first to admit this isn't the prettiest dyno I've ever done, but I'm sure we'll all agree that the numbers are more like those expected:
15.85PS @7270rpm, 15.51Nm @7090rpm, max rpm = 8457 = 95kph = 60mph in 3rd, max temp 119ºC (only short WOT in 4th) (I have another dyno that says 19.9PS @7171rpm, but is dubious)
…..So, after the recent jetting mods, after the seat factor is solved, and when I'm not stopping in 3rd because of running out of road, and going on into 4th, I'm now getting better numbers – AND I've got rid of the splutter!! - Happy days.
(I know we need some proper MD runs to prove these numbers, starting low in 3rd and revving-out; I'm still much happier with sound, acceleration, curve and numbers anyway )
Edit: - Quick additional point regarding revs:
This might be interesting for some; it's the same sound recording – the fast through gears WAV, played back with an RPM app showing revs. I know this isn't a good method, and it is only any good above about 5,500rpm anyway, but above that it does show the max rpm in each gear, and it does tie in well with the MD max revs on the Dyno result above, so is worth showing. The ones worth noting are:
3rd gear: max = 8478rpm = 95kph = 60mph 4th gear: max = 7590rpm = 114kph = 71.5mph (this clearly could have been wound up more on a longer run, and also ties in well with the max – 72mph – that I got a few days ago when I got 144ºC on a longer run).
I've done a MD dyno graph from the first recording above – the slow 1st, 2nd and full rev-range 3rd, and it also gives a good result; in fact a little better than the one I did this afternoon - I thought it would be too short, but had a look anyway, and it gives a good shape and numbers:
This is now much more like it You must be pretty pleased with it now?
This is more like what we were thinking from the start. Would probably make 20 with an expansion exhaust. Might be a bit better in the Summer, once settled in. A few lessons here though, about how important carb set up is and how much difference a bit of careful barrel porting makes.
If you overlay the old engine on this MD, it will show quite an increase in the mid range torque curve, just where a tourer needs it.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
This shows it all very clear. What a good job that was. There will be some small loss right at the bottom. If the lines are extended to zero you can see a small loss around 2500 rpm but nothing much that matters. Edit; even with this loss the Beast still has more bottom end than the 225!
My polossi is fast road tuned with a big expansion so no comparison really but does show you need double the power for that extra 10mph. Vespasco's is 4cc more than mine. In 4 strokes cc is everything but you can see here in 2 strokes it doesn't mean so much and porting is everything. You would give Vespasco a good race and yours being the superior PX frame (*with disc brake) we know who would win!
Once fitted I would get rid of the Vespa filter on the carb. if you have to have something on the carb one Vortex thing similar to this would be great modernvespa.com/forum/topic108115
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Yes, very pleased indeed with shapes, colours, noises, numbers etc.; I'm sure there's no end of tweaking can (and will) be done, but not for a while – gonna have a good few Spring blasts first. That won't be this weekend though by the looks of it; I've just got home after riding through a bleedin' downpour along the windy rivers for lanes in the pitch black:
Must be monsoon season.....?
I've ordered the filter, so I'll have a play with that, the seat and jetting when it arrives, but other than that, this seems like a good point to have a breather.
Thanks for all your contributions during the build; hope you think it was worth it – I certainly do:
I noticed your edit this morning, pxguru; I did identify the bits you were referring to on mine yesterday, and I can see what you mean about the 225 too, except mine against mine is a more like-for-like comparison (Same scooter/rider/road etc.) than mine against vespasco's. I've done one, and I'll quickly knock up the other chart, just to complete the picture; it's not as if I'm rushing back out this morning!
Old Faithful Vs The Beast – Below about 3,200 for power and torque:
Because it was raining yesterday.............................
I'm not sure how much a direct comparison between our results can be taken as reliable, but it occurred to me it might be interesting to compare at what speeds we each reached our maximum power, and at the point in the rev range on our dynos where our powers are about the same. Also unfortunately we've only got 3rd gear data, so how well this transposes into 4th gear I don't know. Here's some numbers anyway.
Vespasco's gear/speed chart highlighting his max power at 6618rpm and parity at 7200rpm: 3rd gear Max power = 6618rpm = 83kph = 51.9mph 3rd gear Parity = 7200rpm = 90.3kph = 56.5mph 3rd gear max revs?? - I'll see if I can find it elsewhere......
This has reminded me of one point that has been overlooked. Gearing. I don't think there is anything wrong with the gearing you have for touring. For this function it's about right. If however, you did want it to go faster in 4th, you can see that max revs in 3rd and 4th are too far apart. For fast Road the difference should be about 500 rpm. To get yours to have a faster top end it would need a lower primary but then the cruising rpm would be all wrong.
Overall with yours it's all way better than before. I imagine it's very comfortable to cruise on now.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Yes, the gearing difference dawned on me whilst I was comparing our revs and speeds on the dynos over the weekend; it isn't bothering me at the moment - I don't need faster in 4th. Riding this now is splendid; getting used to it too now and the 70mph+ isn't bothering me, although I keep finding myself being too quick when I join the dual carriageway and being right up the arse of the traffic I'm joining - don't need to wind it right up any more. I'll be getting some more typical riding done now in the next few weeks; climbing up and opening it up across the top of the Moors. Not much traffic, but have to be careful of sheep and horses doing unpredictable things. Really looking forward to some proper good riding now.........
Oh, another thing.....I went to fill up it this morning, after my 100km gestimate of fuel consumption between fills, and only got 4.5 litres in the tank; very good economy.
I know this is not what you want so just for the other readers, if you were to not want the scooter for touring and cruising around on but wanted it faster top end your 21/68 primary ratio would need to be changed to 20/68 which is then the same as a T5. Just a 20 tooth clutch gear. If you then could make 8100 rpm in 4th it would then be doing 75mph. If that wasn't quite low enough gearing in 4th then you would need the T5 36 tooth 4th gear and would then be a full T5 gearbox. Although, if you were to want it faster, then really it should be tuned very differently with some more porting and an expansion would be essential. And then you might not need the lower gearing at all!
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I'm suprised that lower gearing would get my top speed in 4th up, and I don't want to confuse your point for others, so I'll be brief. My gearing at the moment (21/68 & 35 4th) would give me 75mph at 8000rpm, and I reckon it would get there now. I'm at 7700rpm (72mph) without wringing it's neck, and will be a bit more confident on drier roads, know my temps are reliable, and when I've got the tubeless rims on. This is my table now, which shows 8000rpm will give 75mph:
Filter looks just what is needed. the vortex thing would be nice to have but not essential. Some jet adjustment may be needed, could go either way!
My calcs for your gearing were similar speeds. To go faster in 4th the gearing needs to be nearer the max rpm achievable in 3rd. I understood that the 7700rpm in top was just about it, if you think you can get over 8100 rpm in 4th already then you really should think about a bigger clutch gear (22) for the touring duty. For touring you should have closer to (but not more than) 1000 rpm between 3rd and 4th. See how it goes on real life runs across the moors and decide in a few months. The clutch will need to come out to be checked over at some time near Summer anyway.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I'll digest this better after giving it some thought in the morning when I'm not so distracted, but a 22 clutch gear was what I had expected you to say; I'll read and understand better before adding more.....
Right then, I got a bit bogged down with other work, but I'll see if I can get this right in my mind now. It is only about understanding your point; I don't feel the need to change anything at present, but if I'm going to have a clutch inspection and will have a better idea of my long/fast/hilly performance too in the next few months, understanding this might be useful if I do upgrade the clutch and keep this one for Old Faithful, if I don't break it before then – I have just got a cheap 2nd-hand standard mk1 for that engine, that I've stripped and rebuilt ready to fit, but this is another option.
Here's what I've recorded with this engine and gearing: 3rd gear Max rpm = 8639rpm = 97.1kph/60.7mph 4th gear Max speed = 72mph/116kph = 7650rpm.
So at present my Max rpm in 4th is just within 1000 of the Max rpm in 3rd, and will probably be closer once it's all settled down, when road is dry, when I know my temps are consistently OK, and I'm a bit more confident giving it full beans in 4th for a bit longer to get the rpm and speed up a bit; maybe 75mph:
So; if 4th gear Max speed – 75mph/121kph = 8000rpm is achieved, there are two statements that I'm trying to apply to those figures:
“For this function it's about right. If however, you did want it to go faster in 4th, you can see that max revs in 3rd and 4th are too far apart. For fast Road the difference should be about 500 rpm.”
“To go faster in 4th the gearing needs to be nearer the max rpm achievable in 3rd. I understood that the 7700rpm in top was just about it, if you think you can get over 8100 rpm in 4th already then you really should think about a bigger clutch gear (22) for the touring duty. For touring you should have closer to (but not more than) 1000 rpm between 3rd and 4th.”
If I can get my revs to 8000rpm, speed to 75mph, then I'm near to/within 500 rpm, which you've said would be right for fast road set-up, and which you say for mine would probably mean I should look at a 22t clutch gear, but we don't know what Max rpm I'd then get in 3rd or 4th, but I can do a table, for leaving the gears alone and changing the clutch to 22t:
I think you have it now If yours will go over 8100 rpm in 4th, then for a touring set up, it should have a 22 tooth clutch. If 7700 rpm it all it will do then the 21 tooth is ok for touring.
For the fastest speed in 4th, I think the 20 tooth would achieve this but it wouldn't be very nice to ride long distance.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Good; that's clear now then; I'll have some more reliable numbers to help a decision later, which I can tie in with a clutch inspection and decision on that too. More on my mind at the moment is this slight lull at low revs, say from a standing start, where it takes a moment before I really feel the pull; it shows up still on the dyno, and on my 0-60s. It's much better than it was when I had the real stutter, and I can probably live with it (will have a better idea when I tackle a few bigger, windy hills), but I'm wondering if a BE2, or a modified BE3 might help with a bit more lean lower down, and, as it will affect my jetting, I'm wondering if it might be a good idea to have a look at it before I rejet for this carb box filter change I'm going to make next time I'm outside. Do I want some holes at the top of my atomiser to help that lull? I know the position of my pocket in the slide (04) is relevant too, but it seems easier to think about and tackle this first.
I would change the filter first. If it runs slightly weaker overall. it will fix it. A be2 might be too much. Even though any rich problems now will be worse in the summer. Are you positive it is rich splutter and not weak hesitation?
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Righto I'll do the filter first to see if that improves it.
I think rich because it improved as I decreased my MJ, but is still just present now MJ is right for the rest, so I thought a bit more air just there might sort it. I wouldn't say it's a splutter or a hesitation; it's just like there isn't enough torque/power at the point to overcome the inertia until it's rolling a bit – especially from a standstill, especially on an incline; there is a real noticeable point after it where it really picks up and pulls. You can see the point on MD dyno – after the 'bottom end losses' there's a flattish spot in torque and a corresponding lower increase in power between 3000 and 4000 (18-35kph/11-22mph-ish), and it shows up in low low-speed acceleration in 0-60s too. Not a big deal; some of these bigger hills will tell me if it's going to be a drag at that rev-range or not. I seem to have accumulated several BE3s ans E3s, so maybe later I can add tiny holes to a spare one to see if it helps and swap back if it doesn't, but I'll do the filter and see anyway.
I think you're too busy for this next bit, but I'll get it down here because while it's been so cold and wet here lately my mind has gone back to how this ties in with the info I was gathering for the carb animation. I'm thinking that my rev range is roughly 8000; and that can be divided into Idle, Progression, and MJ circuit with the MJ divided up as atomiser holes 1-6, in such a way that, if not too much of an oversimplification, I could, maybe, say approximately hole 1=2500/3000.....hole 6=7500/8000 – with the corresponding drop in fuel level in the MJ. Being able to divide the slide position (%ge and mm), revs into the circuits and corresponding hole positions and fuel level, will help understanding how to pin-point localised tweaks like this, and also progress my animation, which I would like to complete when I have all the info together.
Neither of the above are important; I'm mainly still working through a few final tweaks and changes, and a Spring check-over and service – when other work and weather permits – with a view to getting some longer runs in over next few weeks; nothings stopping that except enough decent outdoor time to get it done.