Hi all, Appreciate your comments, bike is a 1999 Gilera SP50 with 70cc stage 6 streetrace and Leo Vince ZX pipe. Its done about 600 miles since the top end was fitted, so I'm guessing this plug has covered about that distance (previous owner had put 500 miles on the kit before I bought it).
Bit rich. A lot of carbon deposit for the miles it's done so far after the new top end. What size is the main jet?
Thanks Steve, yes was thinking there was a fair bit of carbon build up going on. Couldn't tell you on the main jet as it was all done by the last owner, but sounds like I should check, I did get a spare with the bike which is a 74.. The bike came with a full tank of fuel (not sure what it was) and had been run on Millers fully synth on autolube with the last owner also adding to the fuel in the tank but didn't advise the amount. I'm now running super unleaded and Castrol Power 1 Racing fully synth, adding 50ml to 5 litres in the tank. does it make sense to stick a new plug in once the bike is flushed through with the fuel/mix and oil I'll be using going forward and go from there before making any other changes?
May have been running too much oil in the fuel when combined with the oil pump as well. I would check that the oil pump belt is indeed intact first, it's hiding behind the variator, runs off the crank. Change it just so you know it's been done. It's a miniscule amount of money (£3/£4) for what it does. I personnally wouldn't have used fully synthetic oil as a premix, Castrol actevo 2T is good oil, about £10 a litre but good oil. There is a premix guide on here somewhere to give you an idea of ratios, somewhere at the top of the home page I think.
