I have a B&S xr950 on a splitter. It has always pinked when cold , right from new. It will now only run with a little choke. I have always had a dislike for briggs carbs, but have always found a China replacement to go straight on and do the job by far the simplest solution. I do not seem to be able to find one in this case however, so it has to come apart. It seems the briggs carb could be 209-90542, . The parts system seems to me to be unusable. The motor itself has engraved/ punched into it 130g32 0101f1. If someone is familiar with these perhaps they would give me a few pointers as to where the problem might lie. I have no problem with chainsaw carbs, old SU types, Stomburg etc but these I just can't fathom. Any assistance will be most greatfully received. Thanks.