Exhaust port colour GS1000 help

[NitroGS]

Hi Guys,
Winter is just around the corner here in the UK and I am now stripping, polishing and inspecting my pride and joy 1979 GS1000. I would greatly appreciate your help and advice. I noticed on removing the exhausts and looking into the exhaust ports a big difference in colours between cylinders. I have included pic of number 3 cylinder, (i have photos of the other 3 ports and would be more than happy to send them). For numbering purposes I have started with cylinder on the points side of machine calling it number 1 across to number 4 on the alternator side.The number 1 exhaust port is sooty reflected obviously in the spark plug as well. Number 2 port is nice and dark, number 3 port the valve looks particularly a very light whitey colour and number 4 looks fairly healthy and dark. Can anybody suggest the difference why Number 3 port should be so much leaner than the others please.:-|

[Nessism]

Sounds like a good carb cleaning is in order while you're waiting for spring. Also, make sure you don't have any vacuume leaks from where the rubber intake spickets attach to the head which can make a bike run lean.

[NitroGS]

Thank you for the reply, I have ordered 4 carb kits and O ring sets for a carb overhaul and I will give everything a good clean. I was thinking of actually changing the carb rubbers but struggling to find anyone who supplies them, any ideas!

[Nessism]

Those rubber carb spickets are quite expensive, I'd only replace them if yours are cracked and/or dried up and hard. Not sure where to get them from on your side of the Atlantic so can't help on that.

Good luck.

[duaneage]

White exhaust ports are also the sign of lead added to the fuel. It's been 20 years since I saw a white exhaust pipe, they took lead out of the gas here. In the UK and Europe lead may still be added to fuel. Are you running race gas that has TBE lead added to it?

If it is lead clean your hands well after touching it. That lead is easily transfered to your skin and absorbed readily.

[NitroGS]

Hi there,
Thank you for the reply. Just running the bike on normal premium unleaded gas my friend