Modern Buddy

I was looking to get my scooter running at its peak so I checked the valves and they were perfectly adjusted.
I also haven't upjetted with the Prima pipe since I live in Denver and we already run rich natively due to the thinner air.

What do you think of this spark plug? It's the Iridium so the center pin is supposed to be that small.
It looks pretty good to me so I don't think upjetting is needed.
Also, my header is a beautiful golden; no bluing.

Looks about right to me. Could be a touch more chocolate to make me perfectly happy, but looks good. How is it running? no flat spots? no bogging? If so..Keep going. To be EXTRA sure put in a fresh plug and do a plug chop on a new plug and have a look. Look further up onto the porcelain to see how it "reads" up there ,too.

It just doesn't have the oomph or top end it used to. Rarely gets up to 60 bmph on the flats in cold weather. I have fairly new sliders and air filter.
I thought the valves might be off a bit but they felt really good to the feeler gauge. They were done at 13K miles and I'm at 25K now so they sure are holding nicely.

I also thought maybe upjetting for colder weather would be a good idea but I haven't done it since the plug and header look OK. I have 100, 105 and 110 jets in my garage.
I *THINK* the stock jet on the 150's is a 92 and some Blackjacks came with a 98 so I would probably only go to the 100. I found one post where a member found the sweet spot on his BJ at 105 in So Cal which would be sea level.

I agree with viney 266. It looks a little light, but not enough to cause damage. The Prima pipe came dealer installed on my BJ and the jet was increased one size. I'm in Philadelphia, so your point about altitude is also valid. I remember some earlier posts about modificatuin of baffles in the airbox to get more flow. A search should find it. That mod coupled with an upjet and the rollers might get what you're after without alot of effort/expense

Here's the link on the airbox mod. viewtopic.php?t=11141&highlight=airbox

Thanks MGM. I toyed with the idea of the air box mod a year ago or so but decided to leave it stock.
Since I ride in temps that range from the teens to the 100's there is just too much variation in the air density and I don't want to make my scooter too temperamental. I think by maximizing air and gas flow, it just might push the reliability envelope further than I am comfortable with for my daily commuter.