Got to be honest, I don't even use caliper brakes anymore. Front drum and rear coaster, but rely more on the front than anything. I always wore pads out too fast, even with a 2 smoker. I recommend a better brake. If you want to stick with what you have, thats your choice. I understand that you have building experience, and I also understand that people have told you the 79cc produces little more power than a 2 smoker, but if this is your first big 4 stroke, I highly suggest you rely not only on what you have heard and what your prior experience tells you. 4 strokes are completely different from 2 strokes in a lot of ways.
I understand that as well, I have a lot of engine knowledge and have torn apart many 2 strokes. I have some experience with 4 strokes but still understand most of what I need to know. As far as the brake, I will be keeping the calliper FOR now, until I can get something better, I may end up running a sturmey archer front drum like I have in the past. As far as my riding habits, I don't really even use the brakes unless I have to. I'm also an elite member on motorbicycling.com lol, not that it has anything to do with anything, but I've earned that label from skills presented, advice offered, etc. I'm not too active on this forum, seems like my posts don't get a lot of attention. I'm very mechanically inclined and manage to make something work even if it's not supposed to lol. No one told me the 79cc produces a little more power, I know that from experience as well. In my case this engine is only physically larger than a chinagirl and puts out only a little more power. Hardly vibrates at all, smooth running engine, firmly fixed onto the frame. I've built several walmart and other "department store" bikes and I know the type lol. I have to say, I don't have many bad experiences to report using lower end bikes. I mostly build on steel frames, steel wheels. Although, I have done aluminum frames/aluminum wheels...again never had any issues. Never burned up a clutch, I've seized 2 engines(not because of lack of oil or utter negligence on my end, but because I tightened the studs too far and a chip of aluminum jammed the crank shaft. I don't want people thinking I'm going into this project as a complete newbie, I've interacted for several months and researched, got information, etc. If a problem arises, it can get sorted out. Also for the wide crank, my crank clears but my pedals are too short(no foot room) so I think having the wider crank WILL fix the problem, I do have a propane torch(takes longer than MAP gas) and I can bend as/if necessary. I've stripped apart pretty much every happy time engine I've owned, even fabricated my own head gaskets. I've messed with the e clips in the carbs as well, always junk any CNS carb I run into. I usually run #41 roller chain, and run a different fabricated chain tensioner, or just back the wheel up and have the chain tight enough....so I don't have to rely on a "spoke eater". I like running straight plug heads on the 2 strokes too, usually run a 44t or 36t sprocket in the rear. For brakes I use either callipers(if I have to) V-brakes(my favorite) or run a front drum/rear coaster, front drum/rear sidepull, OR front drum/rear V-brake. I'm not trying to sound like "I'm better than you blahh blah" that's not it. I've seen some of your builds and it's interesting to see how everyone has their own intriguing ways of doing things. All of my HT builds have run smooth even when not on the gas, they pull along nicely, I treat my stuff very carefully, clean the bikes after every ride until they are SPOTLESS. I like adding mirrors, performance air filters, old-school speedos, etc. Always doing something to make it unique.