Cynic

Can't see what you mean. Caption sucks.

Great , got that crisp cracking note you hear on the track, getting a bit bloody chilly now though in the mornings. Had ice on my visor today.

Are'nt they unfilterd though with only a mesh screen to keep out rubber, (turns into grinding paste if it gets in the motor)

you will go from 13 to 16bhp, seriously that doesent tell the whole story, you will get probably 25%more torque so you dont need to rev her arse off nearly so much. Makes the bike much nicer to ride. Still left with a realistic top whack of around 55-60 though.

I know when i had TTS tune my old 600 they only remove the airbox on full drag bikes. I have read that having a pipe say 2-3 inches between the carb and the filter can help allowing some static air to help things along. How long exactly? dunno. Worth a try though, 125 motors havent a lot to loose.

I think mine is the neatest. Remove the whole sorry shebang and bin it. In my case, the frame brackets too. I was either smashing em up in the dirt or kicking them to death when i got on the bike.

Surely if you have bought all that kit an extra 15-20quid for a workshop manual wont hurt?

Found it, the floats i had used are actually heavier buy a couple of grammes. They feel like there is fuel in them which would screw up the float height just a little. Must be a pinhole in them or something as its been a very slight issue but getting worse:mellow: Anyhow, swapped the floats then she ran proper shite, lifted the needle a couple of clicks the higher it went the better it got, 170main and lower the needle and ta daaaa. 9000rpm anybody! and smooth as you like from 1500rpm to flat out in a full throttle roll on she's now as fast in 5 as she was in top the torque's back. I think i'd allowed for the extra fuel somehow messing with the needle at lower RPM where she was running on the other jets. Then when she's wide open there isn't enough gas cos the main was too small for WOT. Thank F for that. Happy now Oh the carb IS the one you gave me back og. Its now much nicer than my original

This is based on the fact that the engines are VERY similar, I can see no reason if you swapped the long studs on the twinshock for the short mx ones that a MX top end wont fit. I havent done it but i see no reason for it not to work. My question would be why, the performance is very similar between the TS and the MX.

You have a weak cylinder for whatever reason. Probably a bad spark or blocked jet. Whatever it is the cyl is firing when the valves are open on the 'wasted' spark, so you get flames. When the engine is first started you will most likely have one exhaust pipe that is nowhere near as warm as the others. Pull the plugs out and you should get an idea of whats needed to sort it. Very black/wet will obviously be rich, white will be lean. You are after a nice tan brown colour. Could be something as daft as a bit of damp. Sticky choke would be high on my list too.

Cheeky,

Sorry on that i'm pulling a blank. It may well be but be carefull. There are variations like the AT1-m that had only one compression ring. That may be the cause of the different number. Ordering parts of this age can be tricky. These guy's can help track down some rare old parts. Fowlers Although there is no real reason for the later DT Mx piston not to fit.

Thats the kind of thing i was thinking of, whats in there, a 555 timer and a little 40w relay. Just as a curiosity OG, is it worth a current check on a stock relay to see what it draws.

Yep, surely something like the led indicator relays with an electronic timer inside will take a tiny amount of power over the stock thermal unit.

Nope different 56x50 on the 125 and 66x50 on the 175. The STROKE is the same on both. Thats why the top ends will swap over to effectively bigbore the smaller motor. Seeing as they share the same internals more or less it means you have an incredibly strong 125 motor or a perfectly reliable big bore. Win win situation.

Personally, it think your chasing gosts. The tail/brake light will always dim when the indicators are on as the indicators take such a lot of power relative to the rest of the electrics. I have had 3 different bikes with 6 volt electrics and indicators and in all cases at low rpm or high load like brake lights/lights on etc they were shite. The best reccomendation i could make is track down a 6v electronic signal relay as the heating element in the std signal unit is a massive drain on the system, far more than the actuall lamps.

With a 170 in she is so rich the plug looks like its been dipped in fuel, with the 150 unless the needle is maxed on the bottom notch she will run really badly as well. This is why i posted. I'm missing something but i'm not sure what.

If i lean the mixture off by dropping the needle a notch or 2 the mid range is great but there is nothing above 6/7 grand. Go up from a 160 to a 170 and she wont run at all, but the inverse is true too, go to a 150 and you kicking till your leg practicall falls of just to get her to start. I have a feeling it could be something to do with float height but i have checked that till i'm boss eye'd and its definitely on spec. I might lower it a mm and see what gives. Like i say it goes well enough its just not 'nice' to ride, the throttle response especially is dull and you have to roll off the throttle in the higher gears to find the right spot to go faster then roll the throttle on very slowly or she fades out, this causes the idle to go high if you stop fast from this condition, which is what makes me think its lean. I do have some piston noise, maybe the bore is too worn to be serviceable. Its within spec but has got some slap.

Ok, i'm hoping a fresh approach might help. The 175 is being a bit of an arse, from cold she's fine and starts and idles perfectly with choke when cold and when she wont idle with choke its cos she don't need it and she will idle for 10-15 minutes happily. Thing is when your riding, she's a bit rich in the middle but leans off at the top end. Moving the needle up ruins the low speed (sub 5000rpm) manners and putting in a bigger jet and dropping the needle she just floods out and fouls the plug. Lower the needle without the big jet and she bloody near wont run at all. Add into this if i run her a touch rich but tweak the fuel tap it helps with the mid range but she still leans out up top. At least i think she's going lean, i cant say for certain as with the motor going rich in the mid range the plug is always shitty. I would expect het to be lean. I was thinking float height, but how when she's rich and lean at the same time. Its complex as the pipe is a gianelli after market pipe which messes with the jetting a bit. Stock carb settings just have her sulking and difficult to start so i have got to fine tune things to get it right. There could be a little ig error in there too but i don't want to mess with that as i don't think it will affect the carberation. She starts readily enough so i figure its near enough. Don't panic, she runs fine for trips to work and such its just she's just not running as well as i'd like but feel like i'm going in circles at the moment. Oh and its the stock 24mm carb not the 26.

If you came on the melton road you missed an epic bit of b road scratching and i know the Melton roads good, might have been a bit much for the Widowmaker, you'd work up a sweat on the bends, gets the red mist for me on the TDR. Runs from Melton through to Corby but you could have hooked the A6 down through Beds and Luton for the last pip to the city.

This has got to be a gag, surely no one has the brass to ask for something like this in a first post

Is it me or does the forum seem like its running in treacle at the moment. I use a couple of others and they are fine so i don't think its the PC.

No brainer, Vehicle wiring products. should be a good place to look. Their stuff is pretty good. Good service too, and cheap.

Oh no you bought one of THOSE......... Bloke next door had one for 2 years. His only complaint was it drank fuel like mad. 30mpg and less. That may of been him of course. What are you going to do?, no running repairs, no suspect parts, wont corrode through the winter and comfortable for a sports bike. Where's the attraction,

Best of luck with that, distributors don't run at engine speed, a car distributor runs at half engine speed IIRC and opperates the points 4 times per rotation. Your bike ig runs at engine speed and opperates the points once per rotation. Its probably possible to figure it out but..... Isn't it a bit much for a YB100