|
Post by tocoo on Oct 24, 2017 6:25:25 GMT -5
my motor is the usual 139qmb
Today I will try to put back the original main jet, use the scooter, then let it get cold and try to kick start it.
|
|
|
Post by tocoo on Oct 24, 2017 7:58:09 GMT -5
So with the new carburetor back to its original main jet of 76 and original idle jet of 30, I manage to kick start very easily with ONE light kick. The scooter idles well too.
I do not recall if the two idle jet of 30 [the original of the carburetor and the one from my chinese set of jets] are identical. i will look tomorrow.
|
|
|
Post by benji on Oct 24, 2017 10:40:52 GMT -5
Just cuz a jet says 30 doesn't mean it's right... I've noticed jets can be off, especially cheap ones (the ones I buy). I was gifted a jet drill kit a while back, and it turned out to be a godsend. It has a little dentist drill and some bits that are sized specifically so you can redrill a jet to a specific size. You can also slide the drill through a jet to check current size, i.e. take a 30 drill and pass it thru your 30 jet. It should just barely fit thru. If not, it's the wrong size.
|
|
|
Post by tocoo on Nov 23, 2017 8:27:16 GMT -5
Good news, I replaced the non-original idle jet of 30, by the original idle jet of 30. I kept the non-original main jet of 80 and I waited 14 days. THe scooter managed to start on the battery after 14 days of non-use. I need to kick a lot, perhaps 15 times, before starting on the battery, because there is no fuel in the fuel filter and there does not seem to be enough fuel in the tank of the carburetor. Now I have some trouble with the idle. THe original idle jet is the left, the non-original idle jet is the right I recall that I tested my enricher: -it takes 2 minutes to fully extend to gain 3mm -after I disconnect the enricher electrically, it takes 7m25s to retract totally currently the carburetor has: -needle position 3, from the top, out of 4 positions [the same situation below happens with the pin for the needle at the top...] -original idle jet of 30 -non-original main jet of 80 -I did set the mixture of the carburetor on a fresh day and the weather did not change so far. The mixture screw is always between 1,5 turn and 2 turns from the position of being screwed in and locked. After 2 days of non-use, what happens when I start the scooter via the battery is : -the engine turns over -the scooter idles to 2000--2200 RPMs constantly -2 minutes after the start, the RPM starts to climb at 2300 up to 2600 -after 20 seconds at 2600 RPMs, the engine drops to 1500 RPMs and stay there for 1 minute -then the RPMs slowly oscillates from 1700 to 1900 [it takes several minutes to go to 1900] -the RPMs varies a lot if I shake the scooter on the left and the right, or if I get up and sit brutally on the scooter, sometimes the engine halts if I sit suddenly or if I push the the scooter forward to retract the central stand [ I always put the scoote ron the central stand] -If I use the throttle at this point, the RPMs go up quickly and fall quickly as well. The RPM goes back to below 2000. =>I do not understand why the RPMs drop to 1700 after being at 2600 when the enricher is extended. Normally, the enricher after 2 minutes is extended, it blocks a little pipe for the fuel and the mixture becomes leaner, but the RPM must change only once [which happens to mean ''going from 2200 to 2600''] and it should stay here since the enricher is closed once and for all....
At this point, I go for a ride. In order to test the idle while hot : - I use the scooter, -I sit on the scooter with the engine running -the RPMs drops to 2200 for 20s -then the RPMs drop to 1900--2000 and stay there -if the scooter has been used for 20 minutes, the RPMs do NOT vary even if I sit brutally on the scooter or shake the scooter on the left and right At any time: -There is never fume at the exhaust -the RPMs are responsive when I turn the throttle -There is no gap in acceleration just after the start or even very hot from long use. I do not recall that the idle behaved like this. After I noticed this, I decided to let the scooter rest for 2 days and disconnect the enricher. Here are the results : -the temperature of the air is 16 degrees, isntead of only 10 degrees so far the humidity is near 60% instead of 75% so far -it starts on the battery, the RPMs are around 1900 and after I turn the throttle [or not], the RPMs drop very low until the engine stops -the kick start, cold or hot, does not function at all. I can hear the engine doing a revolution, but nothing happens after this After 1 hour of non-use, Since I modified the mixture from the today failure to idle, I decided to go back to the default settings for the mixture -mixture screw at 2 turns from being locked -enricher is plugged in and this time the scooter holds the idle just like I exposed above. I used the scooter a bit and in 1 hour I will try to kick start the thing, without changing anything. TOmorrow I will try to kick start first as well.
|
|
|
Post by cagiva4ever on Nov 23, 2017 9:49:36 GMT -5
not good enough photos, but almoust.. Always take into consideration the "Static fuel pressure effect" for jet becoming leaner/richer...
about month ago i wrote about idle jet's that i have in my pd18j and pd19j etc cvk collection from 139qmb qma's.
idle Jet structure's varie, regarding where the actual real jet bore starts from. Deeper in the float bowl means Richer static fuel pressure, in layman terms... China made issue problem...
Hence only correct way is to use proper structure Jet(s) Vs the oem type. and also correctly calibrated made jet's from proper brand.
i have here idle jet's that are about 2mm apart, from where the real jet bore starts. that is huge difference, as keep in mind that for example "Float height" tuning is done in 0,5mm steps or less.
Also known brands take advantage of the "Static Fuel pressure" effect regarding Jetting, for example Dellorto uses Different idle Jet Depths among PHBH-series.
the fully extented/drawn-in E-richer needle movement should be little under 3mm. not 0,3mm
on some E-chokes the Needle/piston is Adjustable for its lenght, for its max travel. it has threads in the Structure, glued plastic casing is dismantle able on some models.
the heat expanding little "thingy" inside gets surface corroded by time. it can be serviced cleaned.......and it works then again better....
if you try another E-choke, take into notice that not all E-chokes have same 2-wire pinout.
As you have had the carb on/of from the bike, double check any intake path airleaks (intake manifold Bakelite seal/o-ring. intake manifold itself. "rubber" union tube clamp fittment into Carb air intake side.)
Would also be more than resonable to measure the "Float Height" . when its properly set, the "fuel mixture" screw becomes more responsive to made adjustments VS if it happens that your "Fuel level" is too high.
China CVK's varie alot exactly for idle jet structure and float tang calibration................
if you have 0,01gr accurate scale, Weight the Float and i can tell you if its out of Spec or in tolerance. i have specs from international CoC manufac Approval papers......for china made pd18j pd19j with "white floats" and float bowl/carb surface tilted (NOT level like in Deni carb's.)
also i have 2 measuring specs for ^^ floats. and the mm height data...
|
|
|
Post by tocoo on Nov 23, 2017 10:49:16 GMT -5
Yes the extension of the enricher is 3 mm, not what I wrote previously like 0,3mm. I have more photos of the idle jets: the first 2 pictures are the original idle jet I think There is a blue trace of something on the bottom of the carburetor. I think it is new, I did not notice it so far. I just tried to kick start the scooter and it failed: I can hear the engine doing a revolution and nothing happens. I checked that I have spark at the spark plug and a spark in the coil [once I remove the spark plug] and compression. The scooter started easily on the battery. I also tried with a clean spark plug and I also tried with fuel put on the head of the spark plug. It failed each time. I sum up the situation so far : - original idle jet of 30 + original main jet of 76 = kick start is easy [hot or cold up to 1 week of non-use], easy start on the battery, cold or hot. NO start on the battery [or kick] after 14 days of non-use. THe spark plug is always white or grey - original idle jet of 30 + non-original main jet of 80 = kick start fails now [hot or cold], easy start on battery [hot or cold], the spark plug is chocolate
-non-original idle jet of 30 + non-original main jet of 80 = kick start fails [hot or cold], difficulty to idle on battery [hot or cold]
|
|
|
Post by cagiva4ever on Nov 23, 2017 11:42:17 GMT -5
jet photos still not good enough....
anyway, at this point, actually already at from start, you would need to Rule Out certain things, By doing some Basic proper an accurate tests/measuring.
"blue" trace substance(?) , liquid ? at Float Bowl may be simply a Chemical reaction between ethanol/brass copper....
if you have Ability to do Compression Test do it. its not Defenetive indication but helps. your looking to Achieve at least 130~150+ Psi.
if you would have DIY modded SpargPlug, made to be a "Leak Tester", you could hear any audible leaks from Valve's/piston , 3 places to Hear out any leaking... This DiY tool is a SpargPlug that has Tire valve fitted into it, so that you can pump Air into Cylinder at TDC valves closed (1Kg air is enough and if it holds it all or -10pros after 10~15mins is good). During this pressurised Test, Cranks is good/needed to Lock into position.
Just audible hearing or/and pressure meter (data) connected into valve stem. (if Meter in use,in that case, inner needle valve removed from the Stem)
if you have a BoreScope snakecam, take a look how much/or not much there is Carbon deposit build up on top of your Piston. 139QM engines blowby oil relatively much and even low milage engines can be carboned mucho's...
also some 139QM(B A) engines have notoriously poor quality Valve's and Valve seats at c-head. Seats can be pitted scored corroded Due running hot and lean. also some Valve's loose their Surface/coating (for example many ZNEN scooters). if you have no Taiwanise VTC branded/marked Valve's its 50-50 lottery.
By these tools/tests you can RuleOut certains things, or be more informed.
Generally speaking many China scoots have low service intervals due Mentioned details and need de-carbon work and Valve lapping relatively Often.
in top of all that, if you have any carb issues it wont help at all to Cold start the engine.....
While doing all this scooter fixing and USING alot of the KickStart, be carefull not to Crack it, slam it back or overly over.....Notorius to brake.....
would not hurt either to test see/measure how the Vacuum petcock deliveres Fuel flow. they are Notoriously bad, can actup.... Best idea would be to Replace it with Manual version....For mine (1 of my project scoots) im going to make use of the Stock petcock NUT and lathe make a outlet into it. by so i have correct Chinese "non standard" Thread pitch-shape still, oem perfect fit.
You should also check the Float Pin, to be bullet straight....
so many Basic things.......
|
|
|
Post by tocoo on Nov 23, 2017 13:01:32 GMT -5
not good enough photos, but almoust.. Always take into consideration the "Static fuel pressure effect" for jet becoming leaner/richer... also i have 2 measuring specs for ^^ floats. and the mm height data... A few pictures of the carb. the brand is a ''kungfu'' ek16jm1
|
|
|
Post by tocoo on Nov 23, 2017 13:03:41 GMT -5
I took the carburetor apart. I removed the idle jet and used a bit of carburetor cleaner. As usual, when I use this product, the scooter starts easily on the first kick. I went for a ride and I will test tomorrow the kick start again.
THe carburetor was very clean.
|
|
|
Post by cagiva4ever on Nov 23, 2017 16:01:40 GMT -5
thanks for photos, always usefull as a Comparison data etc.
can you look up for a 1~week old post of mine where i linked a 19mm Float Height setting photo/general purpose CVK video (look it up from my user database)
as your carb has "Tilted" bowl surface and them 2 tiny "Flat Spots", it 19mm Data suits you perfectly. also your Float is exactly same.
Float height looks to be OK but that is only Visual via internet photo observation. do the 19mm measuring check, WHEN carb is USD as in photo. do also a measuring when carb is tilted, 20~45degress, so that Tang doesnt press much the FuelValve's spring'd pin...
look the mentioned linked youtube video and you will understand...
How accurate is your Scale ? naked bare Float should weight 7,3gr. tolerance is +0,40gr.
as mentioned check the Float PIN to be totally straight.
anyway, so far based on so far seen at the Carb, nothing is out of tolerance, radically or minor.
have you Tested that the Acceleration pump works ? see a youtube video regarding how it should Squirt fuel out into Venturi. Have you yet tested how the scooter COLD start after you have "pumped" the throttle (acceleration pump squirts) 2~4 times Prior using E-starter/kick starter ?
its yet Premature to "fortune tell/speculate" but you might be suffering from insufficient fuel flow Due "poor bad" fuel petcock or/and insufficient Vacuum....(reason of cause: valve's leaking, intake path airleaks etc)
you can always connect Via T-connector and extra hoses, a "Automotive Vacuum/pressure meter" into your Vacuum line at intake manifold. There is a visual video reference for it from 139QMB and data, that will be some use. Look for any obvious irregularity on meter Flickering and any obvious irregularity on Vacuum measurement. iirc some of my 139QMB W.S.M 's also have vacuum data....
check also that your FuelTank breaths properly (no AirLock issues..) . Do tests without Fuel CAP on...
your "Start pilot spray" as is is very Atomized when sprayd, it will naturally help as is Due Atomizing well. if you have Poor engine Vacuum, its Opposite for your Carb function.....
if you havent (either) yet checked intake manifolds "bakelite and o-ring" do it immediatelly. look also carefully under the manifold Clamp that it aint cracked under it...
if you are not able to perform pressure and leak tests, you need to do these mentioned other tasks perfectly, into last Detail.
not yet but later you should get/buy and test size #34 idle jet, that is same structure as your Original, as per the Carb you are using. if you prefer any near seal level cold/winter weather riding... When do, look up from genuine Keihin and Naraku aftermarket, if they are same as yours by structure (where the real jet bore starts from..)
|
|
|
Post by greginisn on Nov 24, 2017 1:17:16 GMT -5
Q starts OK but not after a few days or so? Could it be your carb’s float bowl - drain system has a slow leak and your carb has run out of gas? If you don’t have a manual fuel valve installed maybe that could help you?
Good luck, Greg
|
|
|
Post by tocoo on Nov 26, 2017 4:39:36 GMT -5
I think the leak is unlikely since I can start the scooter even after 14 days. Also, the carburetor is new.
Friday, I tried to kick start it and it was fine after a few kicks. I do not recall the RPM at idle.
After two days in the garage, the scooter started with 1 kick. Temperature is 5 degrees and humidity is 60%. The idle was at 2400 RPM before and after I used the scooter, instead of 2200 max. I do not understand why the RPMs change so much.
|
|
|
Post by tocoo on Nov 26, 2017 5:08:43 GMT -5
thanks for photos, always usefull as a Comparison data etc. can you look up for a 1~week old post of mine where i linked a 19mm Float Height setting photo/general purpose CVK video (look it up from my user database) as your carb has "Tilted" bowl surface and them 2 tiny "Flat Spots", it 19mm Data suits you perfectly. also your Float is exactly same. Float height looks to be OK but that is only Visual via internet photo observation. do the 19mm measuring check, WHEN carb is USD as in photo. do also a measuring when carb is tilted, 20~45degress, so that Tang doesnt press much the FuelValve's spring'd pin... look the mentioned linked youtube video and you will understand... How accurate is your Scale ? naked bare Float should weight 7,3gr. tolerance is +0,40gr. as mentioned check the Float PIN to be totally straight. anyway, so far based on so far seen at the Carb, nothing is out of tolerance, radically or minor. have you Tested that the Acceleration pump works ? see a youtube video regarding how it should Squirt fuel out into Venturi. Have you yet tested how the scooter COLD start after you have "pumped" the throttle (acceleration pump squirts) 2~4 times Prior using E-starter/kick starter ? its yet Premature to "fortune tell/speculate" but you might be suffering from insufficient fuel flow Due "poor bad" fuel petcock or/and insufficient Vacuum....(reason of cause: valve's leaking, intake path airleaks etc) you can always connect Via T-connector and extra hoses, a "Automotive Vacuum/pressure meter" into your Vacuum line at intake manifold. There is a visual video reference for it from 139QMB and data, that will be some use. Look for any obvious irregularity on meter Flickering and any obvious irregularity on Vacuum measurement. iirc some of my 139QMB W.S.M 's also have vacuum data.... check also that your FuelTank breaths properly (no AirLock issues..) . Do tests without Fuel CAP on... your "Start pilot spray" as is is very Atomized when sprayd, it will naturally help as is Due Atomizing well. if you have Poor engine Vacuum, its Opposite for your Carb function..... if you havent (either) yet checked intake manifolds "bakelite and o-ring" do it immediatelly. look also carefully under the manifold Clamp that it aint cracked under it... if you are not able to perform pressure and leak tests, you need to do these mentioned other tasks perfectly, into last Detail. not yet but later you should get/buy and test size #34 idle jet, that is same structure as your Original, as per the Carb you are using. if you prefer any near seal level cold/winter weather riding... When do, look up from genuine Keihin and Naraku aftermarket, if they are same as yours by structure (where the real jet bore starts from..) THese are the idle jets I bought www.aliexpress.com/item/Keihin-carburetor-motorcycle-CB400-CG125-250-vice-pilot-jet-spray-PE-CVK-FCR-available-12-injectors/32251289390.htmlTHe petcock, the fuel pipe, the manifold and the vaccum pipe are totally new. I will check the float soon
|
|
|
Post by cagiva4ever on Nov 26, 2017 16:37:06 GMT -5
i dont know how to explain this in laymanterms noob terms.....
everything China made can be Faulty already as New unused. many things can work intermittent faulty.....
if the Intake Manifold is factory NEW, then is super good, higly unlikely it has then any perish-cracks in it....but how about mentioned Bakelite and o-ring ?
Anything bought from Aliexpress higly unlikely is Genuine, so to speak. if item title says "Keihin" it doesnt mean Genuine Keihin made.
that aliexpress jet photo is not worth much. but is only good for outer measures, to see "roughly" how deep the jet is in the Bowl....China people dont usually measure accurately......
Quote: -the scooter idles to 2000--2200 RPMs constantly -2 minutes after the start, the RPM starts to climb at 2300 up to 2600 -after 20 seconds at 2600 RPMs, the engine drops to 1500 RPMs and stay there for 1 minute -then the RPMs slowly oscillates from 1700 to 1900 [it takes several minutes to go to 1900]
for a china scoot like 139QMB this sound about normal, and its all Due the CVK diaphram design issues....
There are variables like Heat expansion, having an effect into Vacuum etc, having an effect into Atomizing and diaphram/slide movement.... some details-functions can actup like E-choke alone, and diaphram with AirLeak.
about only right way is to go Details through and use elimination prosess.
for example you should even measure idle jet's Air emulsion holes to be in Spec. #30 to match genuine comparison #30.
sample of Variables:
lets name summink nasty problem like intermittent "AirLock" in fuel delivery system, like in CVK diaphram with Vacuum petcock system. many engines tend to rise Rev's for a short Peak when fuel start to go too low on float Bowl. When Rev's suddenly rise, it of Course Enforces makes Vacuum stronger, on some occasions this little rise in Vacuum might pop up open Fuel delivery (such like vacuum petcock) for a short while, until it all starts to actup again.
there is no 1:1 accurate method to test petcock, but still as i have mentioned you can Check its feed and diaphram function.....to eliminate any obvious weakness/intermittent issues...
keep fate, you are making progress.
ohh hey tell me HOW accurate is your digital scale ? is it 0,01gr or 0,1gr accuracy or worse than 0,1gr ?
|
|
fhol
Scoot Member
Peugeot Kisbee 4T 2016
Posts: 81
|
Post by fhol on Aug 29, 2018 20:00:01 GMT -5
tocoo: I must say OMG that is _alot_ of work! Did you ever manage to solve it or did i not read careful enough that i didn't see it? I own a 2016 Peugeot Kisbee btw, having some full throttle problems with it (http://49ccscoot.proboards.com/thread/23465/hesitation-on-initial-throttle?page=1) Mine is very tricky to start after 2-3 weeks of non-use but it starts eventually though, after alot of cranking via battery. "There is a blue trace of something on the bottom of the carburetor." I noticed that my air/fuel mixture screw had some blue rubbery-gasket-like stuff on top of it and maybe around the threads (haven't removed it completely yet). Had to scrape it clean to be able to turn screw. Maybe some of that stuff dissolved and created blue stuff inside your carb? Regarding "broken screw on carb": Glad you finally manged to remove it... but judging from the pictures, it seems to me that you might have been able to just grab the screw head using combination pliers, and twist. That is often the easiest way provided you can get a grip on the head.
|
|