Gy6 150cc runs great for 2 miles then I feel power loss?

thesampson22 · 09-28-2013, 07:13 PM

I could really use some help with this problem, I just had the motor rebuilt and the carbs cleaned and jetted. I put a race plug wire and coil and a performance CDI box on it. I just put 500 miles on it since the rebuild. a couple days ago when I was out riding it the motor started to decline in power and took a long time to get up to speed. when I'm going about 45 miles per hour and I let off the throttle and then I roll on the throttle again it feels like the motor cuts out for a second and then comes back on. it idles just fine when I'm sitting at lights but then take off becomes a little laggy and sometimes it feels like the cylinder misses or misfires. I ordered another performance plug and coil and put it on the scooter but it still does this power loss thing. Help Please!!!

skuttadawg · 09-28-2013, 11:26 PM

Do a plug chop to see if it is lean . Same size engine as before or a BBK . Did you check the valves as they may be tight and not opening up all the way to allow air and fuel into the cylinder . Here is a plug chart to see how your jetting is http://www.4secondsflat.com/plug_chart.html A guide to help you check and reset the valves if needed http://www.scooterforumonline.com/in...ic,1720.0.html

thesampson22 · 09-29-2013, 01:28 AM

they did the valves when I had it rebuilt, could it possibly be maybe the voltage regulator cause an electrical issue? or maybe the petcock fuel pump having issues? thank you for the other information by the way. how could I tell if its running lean or not? I'm really new to the scooter scene but I have been trying to work on my scooter since I got it, shops are too expensive if you know what I mean lol

Bob Shaw · 10-02-2013, 07:13 PM

When my 150cc TaoTao's valves were out of adjustment, it would overheat when running WOT and would bog down and die. It is very possible that if they redid your valves, they are seating and need re-adjustment. It's not that hard to check them, and it's free, unless you have to have someone do it. If so, take it back to where you had it done and have them check it. Was there any kind of warranty on the rebuild? I don't think it unreasonable for an engine to need some re-adjustment during or after a break-in. JMHO

09-28-2013, 11:26 PM	#2
skuttadawg Join Date: Jul 2011 Posts: 127	Do a plug chop to see if it is lean . Same size engine as before or a BBK . Did you check the valves as they may be tight and not opening up all the way to allow air and fuel into the cylinder . Here is a plug chart to see how your jetting is http://www.4secondsflat.com/plug_chart.html A guide to help you check and reset the valves if needed http://www.scooterforumonline.com/in...ic,1720.0.html
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10-02-2013, 07:13 PM	#4
Bob Shaw Join Date: Sep 2013 Location: Georgia Posts: 32	When my 150cc TaoTao's valves were out of adjustment, it would overheat when running WOT and would bog down and die. It is very possible that if they redid your valves, they are seating and need re-adjustment. It's not that hard to check them, and it's free, unless you have to have someone do it. If so, take it back to where you had it done and have them check it. Was there any kind of warranty on the rebuild? I don't think it unreasonable for an engine to need some re-adjustment during or after a break-in. JMHO
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