Li150 running issues

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nige1972
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Joined: Sat Oct 25, 2014 8:05 pm
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Hi all, having a mare with an engine I rebuilt and just about run out of ideas so asking for opinions on what I could try next
Li150 with new 26phbh and sterling pipe, no filter, stock original top end with new rings, original crank, new indian electronic with lightened flywheel, new bearings/seals. It wont tickover happily, sort of 4 strokes/ misses and if the slide screw is not fully in it just dies.Runs okish but feels very slow and having the tickover so high its not nice to ride. Tried 55, 50 and 45 pilot and then a 28 delly that ran fine on my 150 and exactly the same issue. Fitted new fast flow tap as fuel was trickling and found major air leak on exhaust manifold which is now sorted. Mixture screw I've had between fully closed and 4 turns out, does run quicker as screw turned in but just dies soon after even with slide screw fully wound in. Timing is bang on 19° strobed, and swapped stator to spare ducati with same symptoms. Pressure tested for leaks and compression is about 105 psi. Im undecided if its an ignition or over rich idle setting but the only thing I havent changed is exhaust but not convinced its that unless its seriously blocked but its too loud to be that...need help on this please :(
mick1
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Main scooter: Li Avanti 225
Location: York
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Cdi, HT lead.........and spark plug, all worth changing. 102 psi is too high for a pressure test, max 5 psi will show any leaks.
nige1972
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Hi Mick, sorry forgot to add changed plug 3 times and cdi. The 105 psi was compression not leak test :)
Muppet
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Main scooter: SX 150 running in

timing
C’est la vie
mick1
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Main scooter: Li Avanti 225
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with the carb' being changed it's looking more electrical. I had an issue with a cracked flywheel/loose magnets which caused a similar problem.

Thinking outside the box, are you 100% the piston's in the right way round ?
Chris in Margate
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Main scooter: Lambretta 1964 225 Special
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Carb (s) too big ?
nige1972
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Had a brainwave today that maybe the flywheel was too light so just got in from work and dug out a standard weight flywheel but made no difference :
nige1972
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Joined: Sat Oct 25, 2014 8:05 pm
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Still no nearer to solving this. Changed stator, flywheel, exhaust, had top end off twice out of paranoia. Piston in right way piston/bore clearance is about 0.0045 thou, ring clearance spot on, just wont idle. Is 26 too big for li150? Checked another 150 barrel and ports seem lot smaller in the problem one. Was gonna get it rebored with new piston but dont wanna do that incase it dosnt solve it. Tried timing at 19 and probably about 25 just to see if any difference.
bristolmod
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Main scooter: Lambretta TV175 S3- what else!
Location: Bali-Hai bar, Locarno Ballroom Bristol, 1967!- mines a Brown Split!!
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remove the carb and inlet and put a standard carb and inlet on and see what happens.

If it then idles and runs OK then its a problem with the bigger carb.

Chris
Scootering since 1968.
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