Check the needle and seat for foreign trash>>if clear tweak the float a bit leanerI only just tried this mod last week, the bike kept dying at WOT. I have a spare stock carb in parts, so I took the petcock and did the five pence mod, and I drilled the inside out too so its really opened up.
It made a huge differeance, the bike is perfect now, it can run at WOT for long periods with no problems at all. I can't believe I left this mod on my to-do list for so long, it is essential and I will do it to all my stock carbs from now on! Only problem its caused it the float struggles to push the needle closed and stop the sudden surge of fuel, so it gushes out of the overflow if the bike is off or if the idle is too low. I'll work on that some other time, got carbon fiber single petal reed up next
Took apart my carb to clean and find out what was the issue to strave my engine @ WOT. I also found black rubber seal in pieces in the cavity and through out the ports of the carb. I clean it out as well as open up and clean the rubber seal. Put together the black seal and white knob on peatcock. Reassemble the carb and added an inline fuel shut-off vavle. Tried starting it and it won't stay running. Adjusted the A/F screw and no changes. Noticed my Throttle grip has lees room to to go to WOT. Feels like it is sticking.marceloPulled apart my carby about 60 times trying to find the reason for fuel flow issues and then found this mod and opened up the petcock and found the torn black rubber seal to sheet and blocking off the flow. I've done the 5 pence mod and got a good seal no leaking fuel. Engine is running a treat.
Thanks all for the info!
I just pulled the carb out and unscrewed the throttle cable. Added some lube to the one end of the cable and put it back together properly. Two pull and it started up It is revving really high so I screwed in the A/F screw all the way and turn it one full turn out. Still idling high I have both wheels and the chain off, could this be the reason?