Starting problems LI 150 series 3

[Flashcat]

I'm new to the mechanics of engines so plain language please. I've recently bought a 1965 series 3 it's been stored in a dry garage for 16 years myself and a couple of friends cleaned the carburettor and got it going. Got the MOT etc ran for a couple of months just short trips then started stalling and would not start again. After a couple of hours or so it did start again. Checked the carburettor it was still clean, fitted new spark plug and air filter. Went ok but once again when you stopped it , it would not start for a time. Also it's quite smoky when you start up but then clears. Any advice of my next course of action. Hope you can help!

[HxPaul]

With the scooter being stored for so long it could be anything.I'd first check the fuel tank for rust.Change the fuel line,take out the fuel tap and clean the filter gauze.Check the fuel cap vent hole.If its none of the above,the problem may be electrical.If its still on a 6v ignition system,replace points,condenser,coil etc.check all the wiring,earths etc.You can see from this list that the problem could be almost anywhere with a scooter thats been stood for so long.Good luck and let us know how you get on.

[Flashcat]

That will keep me busy for a while thanks for the advice

[johnnyXS]

What is the colour of the spark plug ? it will tell you and us a lot about how the engine is running.

As paul says when scoots are left unused for long periods a fine surface rust forms in the empty petrol tank. When you fill up after a long period a very fine sediment quickly blocks up all the fine jets and filters.
I always advise fitting an inline fuel filter as the filters in the tank tap and the carburettor are inadequate to filter fine sediment and water.

I suspect that you need to tune your idle circuit in the carburettor. This consists of the slide , pilot jet and air screw.

You shouldn't need to give the scoot any throttle whatsoever when starting if it is tuned correctly. If you apply throttle you are likely to flood the engine

When you get the engine warmed up first set the idle speed so that it is not too fast but the engine still idles without faltering . Adjust the air screw in or out 1/4 turn at a time . You are aiming to achieve the highest smoothest tickover . You need to give each adjustment at least 20 seconds or so for the tickover to stabilize before the next adjustment.nIt might help to rev the engine a couple of times after each adjustment then let the engine settle down to a steady idle before making another adjustment.

Once you have set your idle mixture for the best idle you may need to readjust your idle speed down again as it will probably have increased with the air screw adjustments.

You should now find that the scoot will start first or second kick with zero or little throttle and tickover smoothly and strongly. Hot starting should be first kick once you have the idle air mixture correctly set providing there are no other electrical or ignition /timing issues obviously

[Flashcat]

Thanks for your input all good advice. The plug is a new one and is grey not wet the old one fitted after it came out of storage was black when I replaced it. Started first time when I fitted it but had more problems same day.

[johnnyXS]

well when I first ran my LiS150 after a long spell of non running I had exactly the same symptoms that you describe.
I had to replace my original carb with a 22mm Jetex one so I had no idea of the correct jetting for my engine.
It took me a little while to get it running and starting reliably but the critical changes I made to achieve reliable hot starting was to the air mixture screw and idle speed adjustment .
The main jet and atomiser plays no part in starting, idling and initial throttle response or transition off idle.

Let us know what carb you have fitted , the engine size, exhaust type, pilot jet and main jet numbers and the atomiser also.
The number on the slide would also be helpful.