Can anyone help.Ive bought pipe part number 18330-NN4-L70 to de-cat my 4ride but it doesn't fit the silencer.Have i been told the wrong part number or do i need to modify it.Any help would be appreciated. Pete

The 18330-NN4-L70 headpipe is for a 300RR. If the only issue is diameter of headpipe is too large where it fits the silencer, and length looks right, then you might be able to use the 300RR Muffler Packing 18391-MB0-891. That would be if the 18391-MB0-891 packing has the same OD as the 4RIDE 18391-HB7-000 packing, so it fits in your 4RIDE silencer.

You may be able to measure at a Honda shop. The 300RR 18391-MB0-891 packing originally came on VF700S in 1984, and has been used on dozens of different models since then, so it's a very common part.

I tried 2 different front pipes from 4RT's and neither were the correct length/angle to fit my 4 ride, in the end i just chopped and welded to suit. Overall i think i had the better solution as my pipe is now extremely close to the motor making for a narrower bike. (closer to the motor than the other 4 rides i've seen on the net with a decat front pipe)  Sorry, not really much help!