My Lui 125 conversion

That looks and sounds the bizz, well done. It's been a long process for you, but you must be chuffed with the result?     

Sounds and looks great Snails  

Thanks. Got the centre beam on eventually, not without the odd scrape. What a pain in the backside that is. Used the rubber trim that Wack advised on but could not get the bottom end rubber on, so that's staying off for now.

Just been out to give her some test runs and I have a problem with it dying.

With the choke out and no air filter its ok in 1st and 2nd but dies a death in 3rd. If I try 1st without choke it just dies. Any suggestions. Originally I thought jetting but I would not expect it to die in first without even getting into motion????

Would an air leak on the carb be a possible cause?

What jetting are you running? I'll dig out my current set up this evening. Standard carbs don't like running with no air filter but not quite this dramatic. Forget the standard filter. I'm using a k&N cone shape but will try a foam UNI type as I think they look better. The large Delorto 'mushroom' filter I posted on here was too restrictive despite it's size. The foam inside was too thick and probably designed for an engine with more 'suck'.

I will fit a filter and see what happens. Just got a universal one to fit. Jetting is std Vega but larger main jet. 80 I think. I wanted to fit an 85 whilst running but could not find one.

Whilst running in

Snails, yours is a 125 correct? This may be your problem. On my 125 (standard silencer, 20mm carb) I'm running a 5914/2 slide, 50 choke, 45 pilot, 5899/2 atomiser and a 103 main jet. Plug colour is a nice mid brown. This set up is not 100% perfect but pretty near and it pulls really well through all gears. I'm thinking, from my experience, you are too lean on the main. Please don't take my jetting as gospel but I've posted it because it works for me.

Paul

Thanks. I took my jetting of an old post off Adam Winston on LCGB running similar set up but willing to try richer set up as don't want to risk blowing it up so interesting that yours will run such a large main. Did you ever try yours with No 6 atomiser?

Talking of buying jets this is an 85 main that I bought thinking it would fit but it was the wrong size thread. Can you tell me what I should be checking/looking for?

http://m.ebay.co.uk/itm/260846711597?index=9&nav=WATCHING&nid=85702958591

If it's the wrong size how did you get it to fit and run the bike up? I'm confused. Jets for SH/1 and SH/2 carbs are smaller I'm sure. Without checking I'd say 5mm. I'm not an E Bay'er but from others experience posted on forums you've got to know what you are buying and the seller is truthful. My advice, if in doubt, is to buy from a reputable dealer and explain what it is you are trying to achieve. When you've taken their free advice then continue to support them with future purchases. Sermon over! I've not tried a -6 atomiser. The way I started my jetting trail was to look at the jetting for a 125 Special/ DL125 (same 20mm carb) and work from there. Again from memory these 125's have a 98 main.

Thanks Paul - I never did fit it, I'm still running an 80 I think.

You are spot on with the thread size

http://www.ebay.co.uk/itm/DELLORTO-JET-1486-SIZE-103-x-5mm-THREAD-LAMBRETTA-MAIN-JET-or-VESPA-PILOT-JET-/321267093555?pt=UK_Motorcycle_Parts&hash=item4acd02d033

The reason I bought from ebay was that I could not find easily find someone who stocked an 85.
Also they tend to have either minimum order amounts like Scooter Resto's or charge about 3.50 postage min for everything which I didnt want to pay for something so small.

   

I've been on holiday for a few weeks but have fitted the 103 and it's improved things a lot. It still does not have a lot of power when first put into 3rd gear but I am only running her to the end of my road and trying to be mindful that I'm supposed to be running in. Not easy when trying to get up to speed on my road so will try a naughty longer trip to make up my mind whether can run like this. Also need to check plug colour.

Of course I guess a lack of power in 3 rd could be a little bit to do with the gearing ratios maybe????

Well I thought I was ready for the MOT but it seems to have an issue with blowing bulbs. It will do this at high revs so I guess the feed to the lights is not being regulated. As its a brand new regulator from MB my moneys on way I have wired it up. Its strange though as I did check the lights feeds amp reading when I set it up and it was fine at the time. Oh well looks like I need to get at my oh so easily accessible regulator.           

Ed, before you changing the regulator if it's hard to get to, are you using L.E.D bulbs in the tail/brake , speedo bulb? You are on 12v so could you up the front headlight wattage and use a standard rear set up so more electricity is absorbed by the bulbs. Also check the rear lights for a good earth.

Thanks Dave.

I don't have a separate earth wire on my rear light. I will fit one. How (where) are these normally earthed to?

I'm not using LED's anywhere and I think I have larger than std wattage front bulb fitted, but its a good idea I wonder if any larger sizes are available.

..probably vibration killing the bulb..especially on a 125.......rubber mount the bracket and the light unit..fit LED bulb...

My first guess was vibration sio I took off rear light lens, started scoot and left it on stand. Revved engine and watched the bulb blow.

I had exactly the same problem. I'd made a schoolboy error. I'd transposed the brake and rearlight wires in the rear lamp.

Paul

Very good shout Paul thanks

Snails wrote:Very good shout Paul thanks

Tried it, it blew even quicker. Oh well

If the earth is good it might be time to fit a regulator. Try Rex's Speed Shop. They seem to be the go to place for custom electric bits. I spoke with them at a show and they certainly seem to know their stuff.

Ed, I had a similar problem to yours, now I'm not too sure on this and my description might need another to decipher. It's to do with positive earth and negative earth, I'm not sure how it works as I just swapped wires round and I have a ign switch in my system. I think it involved moving the + & - over. Sorry I can't be clearer on this, but if you're electronically gifted you might solve my meaning     

I have a regulator fitted already. Might not be wired up properly. I'm still not sure where the rear light is earthed to on std Vega?

David. You are right I have no idea what you mean. I'll come back to your comment if earthing and regulator set up check does not work.

If I remember correctly the standard rear light is earthed through it's own body and mounting screws onto the frame. If your paint is nice and thick and not cleaned off it won't earth. I often run a seperate earth wire from the rear light unit on all my scoots and bikes to a known good earthing point.

Paul

So Paul, just to make sure I have it right, I should be able to perform a continuity test from the bulb holder to the engine, and if that's possible I have a good earth