Anyone Recognize This Tailpipe?

I'll try to keep this short (something I'm not very good at!)

This bike, a 1982 XJ650 Seca, was given to me by a friend (given because of it's wonderful cosmetic condition!). I knew enough about the bike to know that it had an after-market pipe. I knew enough about bikes in general to ask my friend if when he switched pipes, had he re-jetted the carbs. He response was basically "Did I re-what the who?". So I am assuming that it still has the original jets in it. If it does I assume it would be running lean, and I think there is more evidence of that. It really gives me a hard time starting; I always have to give it a lot of choke, and it takes a fair amount of riding under load before the engine is warmed up enough to maintain an idle without choke (or stalling). At high speeds the power seems to "fade" at a certain point and it just won't go any faster. I replaced the clutch thinking it might have been the problem, but it wasn't. Also, the manifold was very rusty so I sanded it down and painted it with high temperature paint which burned through in about ten minutes of running. My brother (who knows more about these things than I do) says a lean engine will run hot which may explain the manifold.

So!

All this leads me to believe that I need to put larger jets in my carbs. Under some advice I've already recieved I was just going to go up 2 sizes, but I thought I would post pictures of the pipe here in case someone recognizes it and says "Oh! That's a so-and-so pipe! Put in this size jets." I've never changed jets in a bike before, so I'm not even sure if it's ever that easy!

Also, if I do end up going up 2 sizes, will I have to change the needle? And what about the other, secondary jets like the "Idle Jet"? Do I just leave them as is?

Thanks in advance! I'll include a photo of where the pipe's label was, the sticker long since gone!

Jimmytime

 

Looks like a MAC exhaust to me.

 

That flange holding the header pipe into the exhaust outlet looks to be like that of: "Jardine"

I had these pipes on a '79 XS650 Special. I bumped-up the Main Jet one size and it ran great.

 

Thanks for the responses! I'll investigate these 2 brands further.