I just installed the Takegawa cam on Sunday. I was in no rush and took my time. I spent at least 1/2 hour looking for tools and another 1/2 sweeping and vacuuming the garage. I spent at least 1/2 hour getting my pv3 set for a 10,000 rpm limit and flashing the ecu. I spent time disassembling right side fairing and duct taping the screw attachments to keep the side cover from buzzing. I started around 10:00 a.m. and watched how to videos along the way and drank a couple Foster's. I was done around 2:00 p.m. Time flies when you're having fun.
Good tip from video I watched was to zip tie the cam chain to the cam sprocket so that you have 1 less thing to try to get right. Also cam chain tensioner does not need to come out, only loosened via the bolt. In my case, after the new cam went in and the tappets reinserted the valves did not need any adjustment. My bike has no airbox and that made the intake valve check much easier since I could get my eyes in there and see where the feeler guage was going. Once the crank is easily lined up with top dead center, (TDC) both intake and exhaust valves can be checked without turning the crank. There's even play in there where you can tell that there is movement of maybe 5 deg or 10 deg or a bit more where the crank shaft can turn clockwise and counter-clockwise with no cam lobe interaction. It was surprisingly easy.
Net result, I did a speed run with the new cam and increase of the rpm's from 9,700 to 10,000 and did not reach any higher speed top speed from my 73 gps, 77 indicated. I felt like I was going faster when I hit 77 mph indicated but my front end started a low frequency but manageable weave (not exactly a wobble) that I'd never felt before on my Grom. With a possible tank slapper and my engine screaming so much I instinctively ended the abuse. I think I can reach top speed more often now but not sure until further abuse. I'm glad I got the cam in there just in case it makes that little extra.
I'd budget 2 hours the first time. It's a 30 minute job, but you can mess some things up in annoying (non-damaging) ways:
1. Cam chain tensioner loosened too much and pop out? Gotta re-oil it.
2. Ever adjust your valve clearance before? Gotta learn that.
3. Still have the stock throttle + airbox? Oh... you didn't want to have easy access to the intake valve, did you?
All in all, simple job, just tedious in a few ways.