[beatr911]

With the 185 you'll be looking for pretty small gains. Yeah a dyno will be the best way to find them.

With my Concours there is a guy that spent significant time playing with cam timing and the size of the opening of the airbox to fresh air. It resulted in advancing the exhaust cam 7 degrees and closing, not opening up, the airbox inlet to about half the original dimension. This also required rejetting because it made it rich. All told, a noticeable low and midrange boost was found with no loss of top end as found on his dyno. I think the restricting of the airbox inlet allowed the airbox to resonate with more strength as only a well sealed airbox will work. Kind of like a leaky musical instrument will sound really bad.

"Simply" advancing cams is a common way to get more lower end but dyno time and/or trial and error is the only way to optimize it. I advanced the cam in my truck 9 degrees for much better pull in 1st going up my steep driveway when fully loaded. You may be able to find an offset camshaft woodruff key for your 185 which would be a really cheap way to advance the cam. It's the origination of the Yamaha TW200, xt200/225 series so parts are common, still available new and may share camshaft dimensions, though there are a few different grinds over the years. Don't advance the cam one tooth, it's way, way too much.