Derbi gpr 50 topping out....

[spakcliffe]

Hi guys,
got a bit of trouble with my 50cc. It accelerates like normal to a comfortable 40 ish but when you open it up and go 45+ it develops a deep engine tone and slowly dies. You have to slow down to about 2nd or 3rd gear for the engine to go back to normal. It also does it on hills when you open the throttle to keep your speed. Where as before it would easily do 50+ up hills.
Any ideas?

[N cee thirty]

could be crap in your main jet

replace the plug aswell
____________________
'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[swiftb]

Possibly the ht lead/cap breaking down under heavy load. You can replace the cap, lead and plug for about a tenner so cheap enough to change them before looking elsewhere.