Cosmo

Sorry about the delays, you folks are so patient! Needless to say, reformatting the hard drive lost me the automatic login and i've been searching for a week to find my login details... You are right about the float retaining pin, Paul - it can't fall out because of the shape of the fuel bowl. However, i'm pretty sure that it can move either way by about half and inch and while it won't fall out, it can put the float tang out of alignment. Saying that, i've ridden the machine for 20 miles and it seems OK now. I will re-bleed the 2-stroke, as i'm not happy about it but it runs far better, even at high RPM's. The only fault i can find is that it sometimes takes some time to return to idle and likes to sit at 4,000 rpm and gradually make it's way down to tick over. This has become less with riding a short distance, altering the mixture and idle speed to obtain a smoother tick over, riding off again and repeating the process every few hundred yards or so. On tick over, the revs die quickly when you release the throttle but if you are riding, they gradually climb down, even if you pull the clutch in. And because of the inherent nature of the 2 stroke engine going b'dang-dang-dang-dang, this propels it forward when you should be decelerating, resulting in kangaroo jumps! (with the clutch out, of course) Again, this has lessened through twiddling of the mixture and idle screws but they aren't as easy to sort as a 4 stroke. And i'm not a knowledgeable 2 stroke person. Nigels comments regarding the zener are good. As an electronics technician, i thought of this approach myself if Neo's advice failed. Not that i thought it would. But i speed read what he written with the inevitable results and once he gave me a prod to wake me up, what he said was clear and worked well. But going back to the problems, as a few suspected, it was fuel based, not ignition. In hindsight, i should have stuck with 6 volt electrics and sorted the carburation out first and then converted afterwards. As it was, i was unsure whether it was fuel or electric related but Neo and the other folks assured me that their conversions worked and once i checked the ignition side through, this confirmed what they said all along. And the bike ran perfectly prior to being stored. Needless to say, i have a new fuel filter installed and i let it run dry now so there is no fuel in the carb to gum anything up once i park up. Saying that, i have a Z1100R1 Eddie Lawson replica with the same fault and that machine has four carbs to strip...groan! And my Ultrasonic cleaner is too small to put the four carbs in as a whole, although this would be a foolhardy approach - each carb needs to be stripped prior to immersion for best results. The seat for the bike is being recovered as i write and i have installed American reflectors on to the machine after locating the hardware stateside. I have also modified the sidelights to run American lighting as well as UK lighting at the flick of a switch, and that took some fabrication of the bulb holders within the indicator stalks for the factory look. But you folks have been a great help and i can't thank you all enough!

Many thanks for the update, especially when none of you have heard from me for a while. I apologise profusely - but my father got rushed into hospital with a blood clot that moved to his lung. Needless to say, everything else just got put to one side while i rallied around to support my mother and help her cope at home. My father is OK now and will pull through but he looks as if he has done six rounds with Mike Tyson with the treatment. I won't go into details, as it will put you off your lunch but sometimes the remedies seem far worse than the symptoms... The information about the coil makes interesting reading. I used to do similar things with TV's to fault find, except we would freeze them instead. But these are niggly faults and can take an age to track down. I'm not saying that i haven't any ignition faults but it seems to be pointing towards carbonation. The bike runs a little rough (see below) but at least seems more willing to rev now. But i won't know until the carb is reassembled correctly. (again, please see below) I have done a little with the bike. After exhausting the ignition side of things, i turned my attention to the carb. In hindsight, the fact that the bike was perfect before storage and then had a gummed up carb should have spoke volumes. A thorough clean didn't help much and in the end, i bought a commercial ultrasonic cleaner. I was lucky enough to find somebody who deals in second hand units, as they cost the earth when they are of a large capacity with a heater, too. And you just can'y clean a carb thoroughly enough by hand. At least i can't... This seems to have helped no end. I say seems to - i have just rebuilt the carb using a carb repair kit and i just need to bleed the 2-stroke and then take the bike out on a spin. The only thing that concerns me is the float bowl retaining pin. Apart from it sliding in, there seems no way or retaining this rod and it could easily vibrate out. While there is no way that it could come out completely, with the inherent vibrations of a 2-stroke, it could slide along enough to take the float bowl out of perfect alignment and thus cause flooding. Maybe it wasn't an issue before because it was gummed up. Has anyone else experienced this or had paranoia about it? On Monday, the seat will come off and will be sent away for recovering. At this rate, i may well join it! Recovering, that is! Thanks again and best regards, Phil.

That's an excellent suggestion! At the moment, the bike is in bits regarding the ignition side of things but once i have the weekend out of the way, i'll follow your advice. Regarding it's symptoms, the bike returns immediately once you back off the revs. It will rev higher off load and it seems better in 1st and second and tends to rev a little higher than 5000 rpm but will still die, where upon it immediately runs again without hesitation once you back off the gas. No stumbling or hesitation as you would expect with a fuel related problem but again, it's all a process of elimination, so i'll get it all put together and give it ago and post the results. Thinking about the ignition side of things, the reading to the ignition coil seems out, so i've found a second hand one as well as an aftermarket one. I'm dubious about both if i'm honest but i can't find NOS. There is a guy in America advertising NOS for MX175's but whether that is a typo on his part or it's another machine, i have no idea. The fact that it's also for other bikes, such as an IT175 doesn't help - it makes me think there may be an MX175, as he has the wording correct for the other models. Needless to say, i've held off on that score. Any suggestions as to the mixture screw? Which direction is to make the mixture lean and which direction is to richen it? And if i screw that screw all the way in, how many turns would you back it out as a starting point? In the meantime, i've ordered a carb rebuild kit and i may well take the plunge (no pun intended) with an ultrasonic cleaning bath. And Paul, some of my readings are out on the ignition side? Suggestions on a postcard, please...!!!... >>>Orange, Meter to 200 Ohms, expect 1 Ohm (HT coil primary) The initial reading was 1.8 ohms but since cleaning, i cannot get it below 3 ohms. This is why i've ordered another coil. >>>White/Red, Meter to 200 Ohms, expect 10 Ohms for mk2 (Magneto pulser coil) I'm getting 12 ohms. Thanks once again for everyone's suggestions! I am going away on Saturday and won't be back until Wednesday, so i'll tackle these things next weekend. I'm so tempted to say ohm, sweet ohm...!!!...hahaha! (it's good when you laugh at your own jokes!) Anyway, back to the plot...by the time that i return, the spares that i ordered should have arrived. And Paul, me old mate, me old mucker, do you recon i need another magneto pulser coil? Everything else out of spec has been ordered apart from the owner...

I'm trying to insert pictures but i'm at a loss as how to do it...

Hello there folks! Thanks for all of the help and advice. This is a case of lack of familiarity and with the advice that you are all giving plus me getting to grips with the bike, i have now found the CDI unit. It whelps when you know what you are looking for! I have been cleaning earthing points on the bike and I've made a new one from the battery negative. I wasn't happy with where it mounted to, as it appeared to have snapped in the past and somebody mounted it in a poor earthing location. Anyway, after much cleaning and testing, here are the results: HT cap replaced - 5.3 ohms. Ignition coil primary - 1.8 ohms Ignition coil secondary - 5.8k Onto the CDI: >>>Orange, Meter to 200 Ohms, expect 1 Ohm (HT coil primary) The initial reading was 1.8 ohms but since cleaning, i cannot get it below 3 ohms. >>>Brown, Meter to 2k Ohms, expect 300 Ohms for mk2 (Magneto charge coil) I'm getting 301 ohms. >>>White/Red, Meter to 200 Ohms, expect 10 Ohms for mk2 (Magneto pulser coil) I'm getting 12 ohms. >>>Black female connector, Meter to 200 Ohms, expect dead short I'm getting a dead short. >>>repeat for black male connector There is little difference when i repeat the tests. I am also getting the short on the last part of the test and an open circuit with the ignition on, so all is well here. All in all, two meter readings are not as per the spec - orange wire and the white/red. I'm starting to think the pulser coil but if it has been changed, it ran fine for 20 years like this. But i'm learning about the machine, which can't be bad. Saying that, at times i think i'd rather remain ignorant and have a running bike instead! Hahaha! Regarding the mixture, when you adjust the mixture screw on the carb, which way richens it and which way weakens it? And is there a ball park figure for setting it, such as all the way in and then screw it out X amount of turns? I've adjusted it for smoothness while the engine is running and i've even tried adjusting it half a turn at a time before attempting to accelerate down the road like a scolded cat, only to have the engine die under load at around 5000 rpm each time. Apart from the tick over, it masks no difference to the running of the machine that i can notice, at least. If this was a car, i'd suspect the accelerator pump but even then it would stumble and hesitate before picking up. Sigh...

Hello there Paul, Cynic, Neo and the rest of our avid followers! I have taken three steps forward and one step back...and i am still struggling. I have removed the flywheel - it is a MItsubishi F3T251 and there are two coils. There are only five wires leading from this, with the exception of what appears to be the neutral switch wire, which is turquoise. The colours are Black, Brown, White with red, yellow and green. I did originally request the location of the CDI but a search of e-bay has shown me pictures of what i should be looking for. I had no idea of what it looked like or it's location but now that i know that it's a plastic black box with many wires, i should be able to test things a little further. This is good, because it means that i don't have to remove the backplate that the two coils are connected to in the magneto. As i'm new to forums, i do not know how to upload photo's, otherwise i'd have done so... In the meantime, a spark plug cap has been ordered...

>>>By all means you can call me Paul...and you are? My name is Phil! >>>Get yourself a new NGK 5k ohms cap I will order one! >>>I take it you subtracted the figure you get from your meter leads only? if so it's out of 10% spec No, i didn't, that was the reading, as is. >>>its the HT coil primary and the tutorial says you should be checking at the disconnected plugs and sockets to the CDI...It's orange there, you already said that yours was high at 1.8 ohms...was this directly at the HT coil and not the loom connector to the CDI? I think this is a case of me not digesting it properly. Maybe i can't see the wood for the trees... I haven't removed any covers for access to the CDI, so this will be my next stage of testing. I checked at the connectors that come out from the loom...assumptions - and yes, i got it wrong, Mr. Mainwaring... >>>Its seems that someone somewhere along the line has replaced the pulser coil for a mk1 jobbie...dohh! I expect this will inadvertantly advance the ignition somewhat! I'll get you to advise on that and no doubt it will depend on what my findings are when i return to the testing of things. Considering i bought the bike when it was less than six months old, i'd be somewhat surprised but the pulser coil has never been knowingly replaced while in my ownership. (and i'm the second owner) >>>Speed reading again lol...at the disconnected (loom side) CDI terminals All noted, Captain! Some things are so obvious. However, re-reading this, it would still have been ambiguous to me...disconnect all wires from there CDI...well, i should have done so directly at the CDI but i wrongly assumed at the loom without gaining access to said CDI - doh! So not only am i learning about the bike but you're training my mind as well! No wonder you're stressed! Ill keep you updated and i'll have a look tomorrow. Thanks once again to one and all!

Would you be kind enough to clarify some points for me please, my friend? I hate calling you by your forum name of Airhead - it seems like an insult - except i know it refers to the love of air cooled machines - however, i can't help feeling a pang of guilt referring to you by your forum name... The HT cap is a little high at 6.3 ohms. It may need replacing. Does anybody know where i can locate original parts rather than pattern items? I like to keep the bike original where possible... Ignition coil primary is 1.8 ohms. Is this within spec?It's almost double the specified 1 ohm reading. (i could have answered my own question here but i want to be sure...) Ignition coil secondary within specs at 5.8 kilo ohms. (5,800 ohms) Now this is where i'm struggling: >>>Black probe on a clean part of HT coil ground point Red probe on...... >>>Orange, Meter to 200 Ohms, expect 1 Ohm (HT coil primary) What orange wire? There isn't one from the magneto. There is an orange wire from the loom to the LT side of the coil. But not in the cluster coming out from the magneto. Back to the test results... >>>Brown, Meter to 2k Ohms, expect 300 Ohms for mk2 (Magneto charge coil) I'm getting 301 ohms. >>>White/Red, Meter to 200 Ohms, expect 10 Ohms for mk2 (Magneto pulser coil) I'm getting 12.4 ohms. >>>Black female connector, Meter to 200 Ohms, expect dead short I'm getting a dead short. >>>repeat for black male connector There is little difference when i repeat the tests. I need more help on this one, though... >>>Black/White, Meter to 20K Ohms, with ignition off expect dead short, with key on expect open circuit, with kill operated expect dead short (Engine kill operation) Where is this black.white wire? It isn't coming from the magneto. Please assume i know nothing! You won't go far wrong and i won't be insulted! I await your response with baited breath!

There was sediment in the tank, so i did a tank clean and also stripped the carb. I could have inadvertently adjusted the float levels without realising, although i was careful not to. As for the markings on jets, no, i didn't notice but it is the same ones that it has always had and it ran fine prior to storage. However, i've just bought myself another air gun and i will strip the carb and use this to blast the airways with some carb cleaner and i'll make a note of the sizes. I'll also make a point in digesting the info that was sent regarding checking the readings in the info that was sent to me. As i've only just walked through the door, i haven't had the time to read them as of yet but i will! Regarding the readings that i said were in spec - the Haynes manual is rather vague here. It refers you to the beginning chapter where there is no mention of it and if you go further back, it's for the earlier variants. The fact that the listed readings referred to this 4th red wire that i don't have, i can only assume that there are a different set of readings for the later model without this wire. All very misleading. Thank goodness for you guys and your pool of knowledge!

The choke makes no difference. I tried this while precariously riding along. If it was running lean, i'd expect it to pick up or splutter. Of course, if it is off load and the engine is running, the choke does make a difference- the engine bogs down, as you would expect. While i am no novice, i am no expert either and i realise its a process of elimination. I will print out your ignition section and digest it later and then re-read it. Regarding the coils, you say the earlier model had two coils and the red wire and the later model didn't have the red wire. Does this mean that it only has one coil? If so, would that mean the stator either works or it doesn't? I'm not taking into account it could be breaking down, etc. But with two coils, the second coil could be breaking down under higher revs under load whereas with only one coil, is it a go/no go situation?

Hello there once again! Yes Neo, your advice was spot on regarding the conversion and i didn't see the wood for the trees regarding the regulation. Had i bothered to read it properly first time, it would have been a lot clearer but you know how it is - you get excited, can't wait to start, etc. I guess i should really read the instructions and i'm old enough to know better... And getting back to my running problem, i have been researching this subject and i see that Airhead was writing to Vambo about the same issue back in 2009. I don't think Vambo evert did let us know if he cured the problem but i realise the information was quite in depth. Regarding the tolerance, you are correct, my machine doesn't have the red wire but the readings didn't seem far off what Haynes published. I say not far off - when checking resistance values on TV or radio, short of actually removing the part that you are checking, a value close to or below is acceptable because other things affect the reading. I realise magnetos are a different ballgame and if it should be specific, please advise. (tolerances accepted, of course) This is another thing i've found with Haynes manuals - i have found through experience that they often take their information from another source. They have you believe they tear the vehicle in question part but this isn't true. I had a Peugeot which had letters to identify the wires but no table to say what letters were for which colour. I though i must be misreading it but i found the Peugeot factory manuals and they didn't tell you, either. And Haynes just copied what was in the factory manuals and hence duplicated the error. (and for those who are wondering did i ever sort it, the answer was yes - but through my own knowledge and also having a second identical vehicle to refer to - and this is the rule with Haynes manuals rather than the exception...) So yes please, do post that head to toe tutorial... And going back to the plot...if i switch the kill switch off, the sounds are identical. I can open the throttle and you get that open carb sound that has no ignition (as the switch is off) but with the switch in run position, the sounds are identical. Yet others say its the main jet on the carb. I admit, the carb has been apart and cleaned using carb cleaner and an airline but i thought i was pretty methodical and past experience with fuelling usually allows the engine to run, albeit roughly. But i only know what i know and haven't experienced this kind of fault before, so i'm over my head with this one - i'll keep an open mind...

Hello one and all and thanks for making me feel so welcome! I apologise for not replying sooner - work sometimes keeps me away for days at a time and i feel kinda guilty when i see how many people have made the effort but it's days before they see my reply. It always amazes me how many folk have these machines when they make their presence know on the forum because you rarely see these bikes now unless it's at a show. MIne isn't immaculate, as it is what i call a working bike rather than a trailered machine. But it's in one piece and i'm proud to have owned her and kept her. I laughed my socks off at Ventura's reference to Triggers broom - how apt! Hahaha! And thanks for Airheads instructions on telling me to open a photobucket account. I will do this and post some pictures once the bike is in one piece. I'm experiencing some problems at the moment regarding the running of the machine but i guess that's for the technical help forum. Oh, the joys of motoring, eh? So, once again, many thanks for making me feel so welcome and best regards to Ventura, Airhead, Blackhat250, Sacha, DirtyDT and Cynic!

Hello there Neo and Rex, Many thanks for your input on this. I have read Neo's page thoroughly and all of the information is there, as he says. I have followed it methodically and made a loom and all seems OK. I do have a problem where the machine dies under load but i'll start another help topic for that, as it may not be related. As far as i'm aware, the coils are for the lighting and the running of the machine. I have tried to follow the Haynes manual and they seem to copy the data from other manuals, so there is quite a lot of info missing and i admire Neo's skills for decoding this! I will briefly mention the fault, just in case it is related but my instincts tell me the fault lies elsewhere... In general riding, the machine will rev to 5000 rpm approx. If you gently use the throttle, it will rev beyond this. This makes me think that it isn't the coils. If i've got the information right, there is one coil for the lower revs and another for the higher revs. Checking the resistance, they are within tolerance. (the additional could being for the lighting) However, the Haynes manuals states a 4th red wire from the magneto which my bike doesn't have. (Red/white, brown and black wires only - the other wires going to a modular connector and don't apparently seem related to the actual running of the machine) I initially suspected ignition - if i ride along and use the kill switch, the sounds and symptoms are identical. However, the bike will run off the magneto alone, so that makes me think it could be fuelling. Then again, with fuelling, it would surely splutter and hesitate if running lean? The bike starts first kick. Tick over is smooth. Running with the choke makes no difference to the symptoms, although it does change the running characterises of the running, as it's rich. I suspected the float levels and i have no idea how to set these - if it's in the manual, i've missed it. But they are unchanged from when the machine was running on 6 volts. However, the bike will freely rev to towards the redline offload, so i'm not convinced it's the coils unless they are breaking down. Any ideas? Is it something to do with the conversion? The only parts changed were what Neo instructed. I am electrically minded but magnetos are a hocus-pocus type of thing and far removed from repairing radio and televisions, which is what i was trained in! And as the bike had stood for 8 years, i cannot say whether it ran fine on 6 volts prior to the conversion. (it used to prior to storage) And i'm loathe to backwards engineer the bike to 6 volts just to see...(i have this sinking feeling that i may have to in a process of elimination but i'll check the local knowledge pool first...) I'll hold off a new posting just to get your thoughts and i thank everyone everyone who has supported me in this quest.

Hello Sacha, Airhead and Dirty DT! Thanks for the greetings - it's nice to feel wanted! Hahaha! I'm new to forums, so i need a bit of hand holding as regards to using the forum, especially the uploading of pictures, as i cannot find out how to upload a picture of the bike. I'm in the process of converting the bike to 12 volts and i struggled a little. However, i only speed read Neo's article and if i had taken the time to digest what he wrote and i read it properly, i'd be a little further ahead than i am now...sigh! Other little touches are that i've managed to get a new number plate made that is identical to the original one that came with the bike, which is a nice touch, as the original perspex plate got damaged years ago. And it's difficult recreating a number plate with logo's and making it legal. However, small touches like this make a difference, i think.