Airhead

I think 15w would be fine Kev, 10w is a bit thin on our newly potholed roads.

Bit thin i would think Kev.

Niiice, reminds me of my mobylette beginnings.

It's all in the FAQ's forum Here ...Paul

Great looking bike jonah, welcome along

Welcome to the forum ste

Must admit i've enjoying the challenge and tinkering with the 125, anyway I cant work in my garage and its usually too cold to work outside on the 175 I have learned a lot of things from this French webforum, they really do know their stuff, its a little difficult with the language at times but has been well worth the effort http://yam2stroke.0rg.fr/index.php?sid=c8bedfc4a4c1646326a2bcba6c88e5b9 Anyway, like I said earlier I need to fit a larger jet when I fit the silencer but because the carb is tricky to remove I wanted to sort out the spare reed cage and inlet manifold I bought. Referring again to things learned on the 'yam2stroke' here http://y2s.free.fr/bac%20et%20pipe/bacetpipe.pdf I have done the work to the reed stops and the inlet manifold. I have seen on other forum and even a mention of it on this one, something about cutting all the robber moulding out of the inlet manifold where it goes inside the reed cage, after consideration though I decided not to do that and to just do as suggested at yan2stroke Befores Afters One before and one after All ready do be fitted now with the jet, the boyesen reeds and the DEP silencer.

Not sure but water in the float bowl can do that. drain it and try again.

'Mechanics' magazine August 82 sent. DT125LC v Honda XL125R.

Andy I have a 'Ride' magazine article titles Last rites, Yamaha DT125 1983 - 2006. It is one page of the writers memories of the brand. Also a 'Performance bikes' magazine, Oct 91. Nine 125's tested. so info on all its road going competition as well as it's trail / road coing competition of the time. I wouldnt go into too much depth of earlier aircooled ones...suffice to say that Yamaha invented the trail bike and set the standard for others to follow, you may want to put a bit of factual meat on that statement. I also have another 'Mechanics' magazine article but its at work so cant give you the detail. If you want me to scan and email them, seeing as it's for your degree work I will do so they might have some interesting quote's and research in them. PM your email if you do ...Paul

Well that was yesterday, today my 3MB head, inlet manifold and reed cage arrived. will get to work on the reed cage and manifold, I now doubt very much that i will wait that long to change the heads, it will be done this year at least...

Like I said though its going to be a long time off, i'm not pulling the head off just to do that so will do it when theres another reason to do so.

Check you have a good flow rate of petrol to the carb. If you do then i'm afraid it sounds like a carb strip and clean, may be a blocked pilot jet. Thats all I know as I havent done it yet on mine.

what model is it? its anybodys guess, could be anything from you leaving the kill switch on or a faulty switch...to coils or condenser down or points shorting or not opening.

More info needed, are you still in dirtbike mode, no keyswitch, no kill switch? no battery? Did you try several spark plugs?

No dont short the switch, unplug the switch and short the plug / socket whatever where the switch was plugged into. Apologies if that's what you meant. Dont know how it affects it so you should get the neutral light working too.

No not missing something, i dont suppose its often talked about but in the case of our 4BL bike's they are fitted with a cyl head of number 3BN. Now 3BN has a strange squish band the likes of which I have never seen before and so I will possibly switch to a 3MB version at the first opportunity. This may make it clearer.

Bloody leccy starts Things are just too easy these days

another class advice from BWJ lol.

As far as 'Bolt on' mod's go the next things for me are Boyesen 2 stage reeds, a DEP silencer and a slight upjet to suit... but the carb looks a bit of a faff to get out and I have other plans to do with modifying the reed cage and the inlet manifold, so I might wait until my bits are delivered rather than have to work in this area twice. Also maybe replacing the cylinder head in time, although I will wait until the first barrel off inspection and rings change for this one Last time (2 weeks ago)I inspected my barrel was through the exhaust port and I could see the herring bone pattern of the honing marks still there

Wahey...nice one mate. Tis a lot better, i'm amazed how you put up with it for so long, i couldnt stand it for more than a day or two. i bet is sounds a lot better when it comes onto the pipe now eh

Maybe so...but the DT is a better bike The neutral light and the sidestand switch appear to be the problem. Shorting the stand switch will no doubt get you going even if you dont fix the neutral light but it's hardly convenient for your son, get them both fixed properly though asap then the youg un doesnt come unstuck by riding with the stand down!

The sidestand switch should depress the plunger when the stand is up (usually). Yes you are wrong in thinking to disconnect it will get you going. When things go wrong here the usual short term get you going fix is to unplug the switch and make a shorting piece of wire with a couple of crimps on to put back in place of the stand switch....However if there is a stand switch problem this should only occur when the bike is put into gear, therefore....have you also got a neutral light problem? Still check the coil back to batt neg, this will verify a good ground path.

Disconnecting the sidestand switch is never going to give a spark, when the stand is down the switch is open and if put in gear with engine running will cut the spark then, usually only a problem when in gear these things. How did you check the coil resistance? what points did you take the measurement from? if the answer is from the LT wire to the coil laminations just repeat this from the LT wire to the batter NEG terminal, this should be the same or you have a bad ground on the coil. Also has the flywheel rotor come loose and sheared the woodruf key?

The reed switch may well be 60mph...but on mine its 80km/h, so if i then use a converter as i have done it would mean reed switch at 80mph for as long as I am using that arrangement. Yeah 4/4 hours is time to do all that ...and...set the PV if it needs setting so thats you and blackhat both illegals now , I will call a meeting to see if we can bar you both