Scooterotica

Hi all,apologies if this has been asked a thousand times,
Got a cutdown with a P2 disc engine,just recently opened it up and it was all in good condition but fitted new quality bearings and seals,honed the barrel and gapped a new set of rings.Ive built a few p range engines so I know my way around them,although I'm no expert!
Running a Simonini,
Timing at the A mark on stator
Carb all thoroughly cleaned out and standard P2 jetting with a 122 main,carb and box lapped on wet n dry paper (carb box matched to carb)
B7 plug,new lead and NGK cap,Ducati coil
New gaskets thoughout
Good fuel flow from fast flow tap

She starts and runs fine,no excess smoke,but sometimes it will bog down slightly when you blip the throttle.Tried adjusting the mixture screw either way from 1.5 turns out but still has this horrible boggy blip.Revs out fine apart from that and comes down do a steady idle straight after.

Any ideas,knackered carb maybe?

new air filter maybe? or yours needs a good clean ??

Filters all clean mate,has two holes drilled in it as well

Happened on a mates t5 - I tried everything (stator, cdi, ultra sonic cleaned carb, rebuilt with new jets, plug, lead cap etc) - only thing left was the carb borrowed one off a working bike and bingo !

that was a dellorto but we changed it for a spaco which worked a treat for a number of years then it happened again recently - again carb change and sorted.

same happened on my p2 - that was a spaco.

24 and 26 can bought very cheap now - I bought two last time so have a spare - got a good deal from india

I have heard others having the same problem with space si

On my last p2 it rode fine for a day or two then wouldn't Rev at all unless choke was pulled out,switched it off and on again and it was fine! Changed plug,lead,Cdi,stator cleaned carb 20 times and it still played up.Ended up buying a new carb and bingo! Might be my next purchase...

Yep carb body had the same with my P2 couldn't figure it out couldn't see anything wrong with the carb but Al changed it and bingo off to Woolacombe it went without any problems.

Sounds like you have the wrong pilot jet to me. What one is in it?

Standard P2 jet 55/160 and I've tried another one as well.Takes 6-7 kicks from cold to start and smokes and smells very rich too.Clears when warmed up though

What size pilot did you try? And what happened with it?

If it clearly runs rich and starts badly with a 55/160, then its not the right jet for your engine.

This will help you m8:-

55/160 = 2.91 < Richer

Jet sizes
45/160 =3.56
36/120=3.33
42/140 =3.33
48/160 =3.33
50/160 =3.20
38/120 =3.16
45/140 =3.11
40/120 =3.00
55/160 =2.91
50/140 =2.80
52/140 =2.69
45/120 =2.67
50/120 =2.40
50/100 =2.00
55/100 =1.82