Hi, Please could somebody confirm for me where the restrictors are and also if anybody has had any difficulty removing the spark arrestor as I have taken the two allen bolts out but it doesn't seem to want to come out, and also if it made any difference. The bike is an 06 4rt.

Thanks in advance

The retrictors are at the start of the front pipe, betwen the front pipe and the silencer, and at the tailpipe of the silencer. Don't take them out, we are losing enough land as it is without excessively noisy bikes. Please note that the stars don't have noisy bikes as they would fail statutory noise tests. At my local practice ground, we are only allowed to ride 4RTs if we have all restrictors in and use a WES silencer- as per Mick Andrews' decree.

I took mine out and it was too loud so put it back in.

Made no difference in power.

Try a bit of love juice (wd40) round the bolts and let it soak in for a while