|
Post by sime66 on Dec 21, 2015 23:11:55 GMT
Cheers jim, It will be interesting to pin this down, and compare notes with others who've tackled similar, and maybe get some conclusions that make a bit of sense. Before going over-rich on the main until this is sorted, I've had really good performance through the range; good idling, good pick up, and surprisingly good performance - BUT too lean. I'm going to open my carb bowl through to the MJ well tomorrow, and we'll see where my jeting ends up then; I also expect rich, and to be redoing Pilot and downjetting MJ. Do you mean you got the DRT top with the 5.2 valve? did you do the float bowl drilling too? What size if you did? I've had a really good read through loads of tap-flow stuff this evening, and checking that is what I'll do afterwards, but given that the oversized jetting test got me black fairly easily, I'm inclined to think it isn't fuel-flow from tank; I'm pretty confident these moderate (as opposed to 3mm, which seemed to cause problems - being bigger than the valve seat opening) carb mods will sort it out. My thinking with mine now is that my orifices get bigger from the jet in sequence, so the float bowl level should remain OK - Main Jet: ø1.5mm(ish), MJ Well-Float Bowl: ø2mm, from Float Valve: ø2mm(x2), Valve seat: ø2.3mm(ish), banjo: huge! That makes sense to me. I don't think it's fuel starvation (to the carb), so much as float bowl level/variation messing up the level in the MJ well (too low), messing with my mixer tubes; this should prevent that now I should have plenty of fuel, but no prospect of float level dropping; that's the theory I think, but time will tell...
|
|
|
Post by jimscoot on Dec 22, 2015 2:25:21 GMT
So the DRTsi 24e comes already machined for the 166-177. Same size upper float chamber channel down to top of brass needle seat. Needle seat has been drilled out slightly but can't tell how much. But comparing size by size you can see that they have drilled this out slightly. Standard needle size but spring loaded Float chamber hole to base of main jet from 1.5mm to 1.8mm
For the px208/210 etc, it's a different part number which does come with that 5.2mm needle. I would dare say the channels will be enlarged even more
|
|
|
Post by jimscoot on Dec 22, 2015 2:30:03 GMT
To be honest it's very conservative and I can understand why after having to lean out the low range quite a bit. I wouldn't drill the jet stack hole out to 2mm especially on anything under 177. Play it safe and drill to max 1.8mm The spring loaded needle helps keep float level consistent under vibrations which in turn will help keep your jetting and fuel delivery/atomizing more accurate according to the dellorto guide www.sip-scootershop.com/en/products/carburettor+dellorto+by+drt+_400000t5
|
|
|
Post by pxguru on Dec 22, 2015 4:16:52 GMT
Sime's one is no ordinary DR177! Will probably turn out to be better than a 210 but we will see once the results are in.
I think you are going to need as near to 2mm as is possible in the main jet way. Once the tank is tested ok there will be no issue with fuel delivery and it can be jetted from there.
Jimscoot, If yours is running with a 190 air corrector it will be leaned out right across the range. I am always against changing the air corrector bigger than a 160. If it feels like you need to it normally means something else is wrong. Usually its just the float level is too high for some reason. A 160 and BE3 is not too rich on a standard set up. Start another thread and get it re jetted better.
|
|
|
Post by jimscoot on Dec 22, 2015 4:30:46 GMT
Will do thanks
|
|
|
Post by sime66 on Dec 22, 2015 5:02:49 GMT
jim; thanks for link; I thought you'd just bought the top and wondered what size you drilled the Float Chamber. pxguru; ø2mm - nothings changed there, did one yesterday, I'll do mine this morning. I wondered what jim had done for a 5.2 valve given the less successful experience vespasco had with bigger holes - just curious, but mine's as agreed regardless, and jim's clarified his. It's not light for four hours yet though , and available time before holidays is such that I'm not going to do the tank until the weekend anyway, by which time, if the outcome is as hoped, this might prove that the flow is OK before then. I'll still do it to be sure and to compare numbers, but it strikes me that it might be unnecessary if these mods sort it. vespasco; "no ordinary DR177! Will probably turn out to be better than a 210" - I'm still comin' for ya! (not literally, not to India; just a figure of speech - I mean, we don't even quite know where you are do we?). More later chaps..................
|
|
|
Post by jimscoot on Dec 22, 2015 7:16:31 GMT
One thing to note with the carb mods is although I've down jetted across the whole range (down to a 140main now), it has much more fuel and power right up the top end. I feel especially confident going full throttle into a strong headwind, or long up hills for extended periods with no sign of drop off in power. It revs much higher in every gear so I'm able to keep it in the powerband between gear changes if needed.
Its a must upgrade
|
|
|
Post by sime66 on Dec 22, 2015 11:16:52 GMT
All carb mods done; D) opened to ø2mm and thoroughly flushed- shown below - those scratches ain't mine BTW; I have a steady hand, E) checked and confirmed open and clear. Carb back on scoot with the A), B), C) modified Dell Float/Filter top with new Needle Valve, Dell 160 AC, and a 148 MJ, Kept the 52/120 for now - No test ride today; it is pouring. Flow tests will have to wait a few days (if necessary), I have a new fuel line too, and just don't want tank out and rushing about in the pouring rain so close to the holidays. I'm going to dry-out and tidy my tools and jets to take with me on a short ride tomorrow; nothing major – only to set up Mix and Idle and see how she feels and what sort of temps and plug we're getting now. If up-the-lane testing/setting up goes OK, and weather isn't too horrible I may go further to do some mixed-riding temp tests like before and hopefully get a better plug, or I might just find a safe set-up and call it job-done for a couple of days; no point guessing now what'll hapen tomorrow, we'll see in the morning. Anyway, here's a pic; it's all back together and I'll see what I can get done tomorrow to test progress/solution:
|
|
|
Post by pxguru on Dec 22, 2015 12:20:01 GMT
Some good progress there. Back on and ready for testing already. If there is any difference you will notice right away. Let's hope it floods a bit and goes down to the 145. If it does that there is no need to test the tank.
|
|
|
Post by sime66 on Dec 22, 2015 19:14:44 GMT
Yep; looking forward to posting some good news in the morning................
|
|
|
Post by henri on Dec 22, 2015 21:21:25 GMT
|
|
|
Post by sime66 on Dec 22, 2015 21:57:39 GMT
There's definitely a gap in the market for consistent, accurate jets (in UK anyway); I've just bought a BGM set though because Beedspeed's ones were so shabby, so I won't be getting any more at the moment, but would be great to have a supply you can trust, especially at £2.50ea. Another good spot though. Talking of observation; you did notice that your order won't be processed now until Jan 4th? Also there's none listed between 140 & 150 on Ebay, but 145 & 148 on KMT website, but it's early days; hope it's as good as it sounds.
|
|
|
Post by sime66 on Dec 23, 2015 9:18:41 GMT
Top Line: Yes, that worked; back in business!!
The Middle Bit:
Weather conditions: Precip: Clear Sky (0%), No rain Pressure: 1018mb Temp: 6ºC (Brrrrrr!) Wind: WSW – 17 knots, gusting 35 knots. (No noticeable headwind on my ride)
I set off up the lane, slugish but not excessively sputtery, and idled where I'd guessed at 1½, so decided to go straight out onto the road without and jetting or tweaks:
Once on road I did notice a bit spluttery at lower revs/gears, and definate drop in performance and temps, so already pretty convinced we were in business, but did very quick temp tests anyway:
Temps - After carb mods, with 148 MJ: Progression chop speed (I'm using 30kph in 3rd) – ± 85-95ºC Cruising at 70kph in 4th – ± 110-115ºC Long WOT in 3rd to longer WOT in 4th and hold – 121ºC Highest recorded temp – 124ºC (after I throttled off from WOT).
Low temps, very spluttery at progression test speeds (needs setting up again, and very unimpressive WOT performance. Definately felt like I wanted to downjet.
Came back to look at the plug – not a chop, or a very long or hot run - just when I got back after 25km, but worth a proper look; there's some colour on cone and some oil:
Natural Colur – no flash:
(If you're thinking it isn't very black, don't forget I've changed MJ from 155 to 148 after carb mods)
So, I'm not rushing about to do more tests and tweaks now, but I have put the 145 in, and I think I'll leave it there, cary a few jets, and just keep an eye on the temp and plug over Christmas. The BGM jets will be here today or tomorrow, so I'll go over to them anyway, for cosistency while I'm tweaking jetting; this 145 will do for now. When I get back to it, I think I can go on to Idle and Mix, idle-rev-idle, smooth, slow-running, getting Pilot right, and Progression Plug Chops....................
Bottom Line: Carb mods did the trick; Lokks like MJ will be nearer to expected now, Indoor tools packed away, feet up – ('til I'm in the mood to fiddle in a couple of days).
|
|
|
Post by pxguru on Dec 23, 2015 9:52:57 GMT
Well thats just perfect! So pleased for you. a very nice point to leave it at until after Christmas. Sounds like its all on track. 148 MJ too rich at WOT and 52/120 too rich at progression as well. Temperatures way too cool and in control. Probably 52/140 and 145 will bring it nearer the performance it was before. Give it a proper run through the sequence next time. What other pilot jets do you have? anything starting with 50? A DR177 running a 145 main jet is still a beast. It is funny how we get used to the new perfomance so quickly. Just think back on old faithful from time to time
|
|
|
Post by sime66 on Dec 23, 2015 10:23:16 GMT
|
|
|
Post by henri on Dec 23, 2015 11:01:12 GMT
an now take a bow , well happy for ya , have a gud 1 , an BAH HUMBUG , had to be done . H
|
|
|
Post by vespasco on Dec 23, 2015 18:14:22 GMT
Forgive me if any of this is now old (or wrong)!! I have to look at one post, reply, then go to the next post. Reply.... *edit Yes ive now read through to the end but will copy n paste my replies anyway..... Yes. Holes to 2mm will be fine Hole D) is a little tricky to get the same angle as the hole. A long series drill really helps. Drilling off-angle is a drill breaker so be carefull. As i think youve sussed already... Do it by hand. Youre right about the pocket.. May contain swarf after drilling. Its a case of thoroughly flushing through from both ways. And do it again. The only tip is to hold the carb upside down when drilling. Drill almost through. Flush it out. Then leave the last little bit to drill so theres not so much swarf that can get trapped in the pocket. Then flush again.and again Jim: The DRT top is twice the price of a cosa top, (once you buy the 5.2mm sprung loaded needle that isnt supplied) Im not so convinced youve tackled your jetting in the correct way.. You seemed to have put in a leaner mj stack to clean up your low speed around town cruising. Im not convinced thats the way to go. See what others say. So now Sime, i think the smallest orifice on your carb will be the float needle seat, which is not recommended to make any larger as the needle may not seal it enough, depending on how big its drilled out *Ah! Just read the DRT with drilled out sealing pad is capable of sealing with a standard size needle!? So i read that as the DRT needle is not a standard part!? Or am i high on the first piece of meat ive had for nearly 2 months? (Chicken MoMo if youre wondering) #Pinasco also do a drilled out "Racing" carb...£75 from italy via ebay. Not a bad deal compated to a new carb and new cosa top etc. One thing about the sprung loaded needle... Could it possibly lead to shutting fuel off if there is not enough pressure feeding it!!!?? I mean, compared to a stock, non sprung loaded needle. In the same way, sprung loaded will also help avoid flooding aswell as the vibrations. Sime, ill be well happy for you if you... nay... when!? you get some crazy figures and feel the force! (but i may just have to cheat and fit a proper pipe and carb on)!! Hahaha. Glad to hear yours has improved Jim. Do be careful tho'. Make sure you're on the right side (rich) of max power rather than being v slightly lean and having max power all the way through rev range. Its a fine line. Yes! Carb mods worked well! 2mm is def the way to go. My experiments went way OTT and got progressively worse (too rich) as i drilled the supply holes bigger and bigger... It may have been possible to compensate by using smaller jets but that, i feel, kinda defeats the object? I ruined a carb and float bowl top in those experiments but all for a good cause! Excellent work Sime. Considering whete you staryed off a year or so ago, its pretty amazing And there is an Indian santa too. Santa Baba. Hahaha! (i think that maybe a personal joke) but anyway, check ya inbox (in a minute)!
|
|
|
Post by sime66 on Dec 23, 2015 19:46:10 GMT
I think your carb was sacrificed, so that others may be spared, vespasco. Once I read your's, and with a bit of encouragement and guidance, it wasn't such a bad job. H, I'm not into Christmas either these days, and it's playing havoc with the delivery of my 2nd hand parts stockpile, but it's good to have a wind-down for a few days, surely? Anyway chaps, it is a good stage to ease-up on the engine-tweaking and just ride it for a few days. Thanks all, for a loooooooong year of lots of sharing your knowledge - you've all done very well! - Take the weekend off...... what shall we build next year..............................................................?
|
|
|
Post by sime66 on Dec 28, 2015 10:14:32 GMT
Weather conditions:Precip: Cloudy (0%), No rain Pressure: 1009mb Temp: 10ºC Wind: SSW – 21 knots, gusting 39 knots. (Felt strong wind – BUT not against me in WOT test this time; mainly strong cross-wind) Temps - After carb mods, with 145 & 52/140:Progression chop speed (I'm using 30kph in 3rd) – ± 100ºCCruising at 70kph in 4th – ± 120ºCLong WOT in 3rd to longer WOT in 4th and hold – 129ºCHighest recorded temp – 131ºC (after I throttled off from WOT). This is the plug I've been riding around with over Christmas; mainly low cruising, lanes and hills – no WOT – less than 100km – not much; it's been wet and windy, so just what was needed; no cruising around. The weather and engine temp figures above are from this morning, Monday 28th. It's generally felt spluttery at low speeds/revs, flat spot if I open it up quickly in 2nd/3rd, reduced acceleration and top speed. Good to have some colour back, but both jets are too rich, and mix screw needs redoing, but it's safe to the point of being a bit sad: (not done loads of angles; it's pretty obvious from just the one – rich and cool.)
I'm going to put the 142 MJ in, and a leaner Pilot; I have 55/160 here now, and some leaner ones coming (maybe tomorrow). When they arrive I'll have plenty of leaner Pilot jets to choose from, so I'll take any advice on where to start. I probably won't try to set up a Pilot until Wed/Thurs, so can probably try with a different one if recommended to do so; these are what I have (going smaller fuel in the 140/160 next):
I'll check the 142** is OK for temps and plug, set-up the Pilot with Mix and Idle, do Idle-Rev-Idle and get rid of any low rev/speed flat spots/spluttering, then do Progression plug chops with a new plug when I'm close again.....
**I could leave the 142 for now, but I'm keen to get some decent higher rev performance back, just to be sure the carb mods are going to be something to stick with; if 142 is better and still not too hot/ lean I'll be happy to leave it alone until after Pilot is sorted – does that sound OK? Won't be anything happening for a couple of days now; just getting this down and recorded in preparation for the next job, which is sorting the Pilot after the carb mods.
|
|
|
Post by henri on Dec 28, 2015 18:09:08 GMT
now thats a better/safer plug colour to start from ,a few tweeks downwards on the jetting an it should be dialled in . an just for info ,a side-wind will still slow you down , just from the rolling resistance from leaning/crabbing down the road to stay straight .H
|
|
|
Post by jimscoot on Dec 29, 2015 0:09:31 GMT
Sime
Your information is invaluable and I'm very keen to hear your results in the coming days.
|
|
|
Post by pxguru on Dec 29, 2015 7:37:53 GMT
Back on the job already! It really is going the right way if it ends up at 142. Keep the 145 MJ and try the 52/140 pilot first and see how that goes. The top end will be a little weaker with the extra air from the pilot. If the bottom end is then looking better and all running smooth and WOT still slightly rich, only then reduce the MJ. If the bottom end is still too rich then you need a smaller pilot. Maybe either 50/140 or 48/140 would be ok. The MJ has to stay slightly (but not too much) rich until the bottom end is all good. Gets really confusing otherwise. Confusing can mean seized up!
|
|
|
Post by sime66 on Dec 29, 2015 7:44:44 GMT
Thinking overnight; I'm going to wait for my other Pilot jets and start with 50/140 and work down the 140s if needed – I know 55 was too big, so it isn't going to be better now. I'm in two minds whether to go to 142 now or later; I'd really like to see some performance back since the carb mods to be sure that it's staying, rather than spend loads of time getting the Pilot right if it isn't. Just as a quick update on the disc forks while I'm at it; they have finally reached the north coast of Europe – with DPD, in Best in The Netherlands, so maybe they'll still be here this year; now where am I going to hide those............
edit** we crossed posts, pxguru; I'll read yours and edit mine if required........
....I'll leave the 145, and start down the 140s as planned; I'm already on the 52/140, so I'll do the 50/140 as soon as it arrives.
|
|
|
Post by pxguru on Dec 29, 2015 10:18:53 GMT
Already ahead of me. How many turns out is the mixture screw on the 52/140? On your fine thread, 2.5 turns is what you are aiming for. More than 1.5 is ok but 2.5 is ideal.
If you check the turns on fast idle and slow idle they will be about the same. The slow idle is the real set up on a carb that has a mixture screw.
What pilot jets have you got and what is on order?
I see you are noticing that "safe" jetting is not so interesting. The actual "knife edge" between decent power and too lean is bigger than it seems. But must be correct right across the throttle range, or it gets confusing!
|
|
|
Post by henri on Dec 29, 2015 11:09:16 GMT
patience sime , youve barely run-in/loosened up that engine , the performance will come back an be 1000's of miles worth ,rather than a short very-fast blast with a unhappy ending .restraint shown now adds years of life to a new-build . your going the right way ,keep it up. H
|
|
|
Post by sime66 on Dec 29, 2015 14:39:40 GMT
I'm reassured the performance will return with correct jetting, no worries; I just had a bit of a doubt that maybe the ø2mm had been too much, but consider me over that doubt now. I've been out this morning, not on scooter, but Dave, the very nice man at Wasp, turned up trumps again with the jets I ordered arriving today, and all the jets marked with a box in the table above are available to play with. I'll leave the rich 145MJ alone, concentrate on Pilot and Progression from scratch as before, starting with 50/140, working down the 140s (got all of them), and maybe skipping over to the 50/160 if/when advised if I get to that point; I note that the /160 would help my MJ with a bit more air through this circuit too (you see; the info does sink in slowly). I remember you saying about setting up fast and slow Idle, but I'll have to go back over that to remind myself why; it made sense at the time, but that was many mince pies ago! The mix screw on the 52/140 was just where I'd left it; at about 1.5 turns – all I did with that was swapped it from the 52/120 and swapped the 148MJ to 145 as last job on 23rd without tweaks, after we'd got some good colour back in the plug, and rode it 'safe' over Christmas. It's funny that after all the messing about with the carb it's the same Pilot that gives me the same flat spot. I'm happy to skip that one and do some proper setting up with the 50/140, which arrived today. Regarding the Safe jetting point; this engine was never intended to be a speedster, but I have to admit I did like how it was when it was what we now realise was very lean. The carb mods and rich jetting have made a noticeable dent in that performance, and I know we'll get a lot of it back with patient and careful jetting, but I will still err on the side of safety, even though I reckon I could have got used to it being a bit of a beast. I'll see what I get done in the next few days, then there's a weekend, but also New Years, so progress is a bit unplanned and unpredictable at the moment, but timescale isn't really an issue, especially if the mild weather continues to be kind. (Hope no one got too soggy in the floods?) All's good, chaps, I've got a plan and the bits I need to get on with it; more soon – you'll be bored of it before me!
|
|
|
Post by pxguru on Dec 30, 2015 8:38:21 GMT
See how many turns out the 50/140 is. Once the mixture screw is over 2 turns out, then move on to progression. By the sounds of it I think a 50 will be right for the pilot. And probably 120 for the progression. Did you get a 50/120? there's no box around that one on you chart.
|
|
|
Post by sime66 on Dec 30, 2015 9:03:56 GMT
I didn't get a 50/120 because it is richer than the 52/140, which we knew to be too rich, and as well as the 50 or lower being likely, I thought the 140 or 160 would be leaner too, which I also took to be reinforced by what you said yesterday about the bigger air helping to lean the top end. I have no problem ordering a 50/120; if I do so this morning It'll probably be here on 4th, but it seems illogical to me to think it would be better than working down the 140s as intended; it's all very rich after the carb mods, so a bigger air Pilot seems more likely to work in my mind – perhaps I still don't understand it properly. I'd like to understand why you think it might be better to try a richer 50/120 than work down through the 140s, but I will order it and try it if you think so – shall I do that?. Last night I put the 50/140 in, ready to set up mix and idle (I do understand that is for the 50, not the /***); it is blowing a gale here today anyway, so there will be nothing doing; probably not tomorrow either, possibly not until W/E commencing 9th Jan if I need this other jet.
Edit** If I'm ordering the 50/120, it would be more cost and time-effective to get any other likely Pilots at the same time; is it likely that we will be working down the 120s, and shall I get any other leaner 120s at the same time? 45? 40? I'm happy to have them for future, but I'd like to cover the possibilities in the next order if more are likely to be needed. I think you've mentioned 50/100 before too; yours? Any /100s for me?
|
|
|
Post by pxguru on Dec 30, 2015 19:35:31 GMT
I think you have it the wrong way round. Once the pilot number (50) is set it remains. Then the air (140) number is changed to set the progression (keeping the pilot number the same). The dividing thing gets a bit messed up at this point.
You are unlikely to need any 100s but might need the 50/120. You have a healthy set of jets already. I would try it first and get the jet if needed.
|
|
|
Post by sime66 on Dec 30, 2015 19:53:04 GMT
You're right, of course! I don't know how I got it in my head to keep /140 and work down; brainstorm has now cleared. - Set the mix (Pilot **/), move on to Progression (Pilot /***); it's in the previous pages - perfectly clear - I lost track: 1. Get it running acceptably on some jetting that you guessed or copied. 2. Adjust the mixture screw for ideal running. 3. Fit a pilot jet with the small number so the mixture screw ends up 1.5 (or so) turns out. 4. Adjust the progression with the big number on the pilot jet (while keeping the now set small number the same(ish)) 5. Adjust the MJ by feel 6. Adjust MJ by plug chops 7. Ride as fast as you like Oh, and: keep going round in circles till its done but Pilot/progression/MJ/Atomiser is the sequence to tinker...My mistake; back to the plot.............
|
|