Question 1 answer: Everytime I shop at Walmart, I look to see if they have a decent front suspension bike that I can install a shifter kit/engine combo onto. The answer is no, the bike in your link WILL NOT FIT. You really need a minimum front suspension because the shifter kit will greatly increase your cruising speeds.
Here is a bike that I've used about 7 times to build shifter kits onto. It is a good looking bike and although not classified as a "mountain bike", I have taken it mountain biking on real mountains, those you find in Colorado, and have gone as high as 12,100 feet with it, gone on 70+ mile rides on trails, with NO PROBLEMS.
The bike is called a Schwinn Searcher and has a steel frame. I would not use an aluminum frame with a shifter kit.
http://www.ebay.com/itm/comfort-cru...957?pt=LH_DefaultDomain_0&hash=item3cc544a4d5
Question 2 answer: Install is pretty straight forward but I've done a bunch so I'm a little biased.
My issues are:
a. Front mount install. I use an oversize muffler clamp mount and use a piece of steel square tubing as a spacer for the engine front mount.
b. Scratching of paint on frame-frequent removal/install of engine with assembled shift kit is often required and this can lead to some ugly scratches/gouges on the paint. Its a cost of doing business, if you are really really careful and patient, you can minimize this.
c. Drive chains tension. You may need shims for the 415 chain on the left side. My PK80 on last kit (never used a PK80 before), I had to grind down the spacer plate because it was too thick, never had this problem before, usually had to add shims.
d. Chain spacing, you may wish to shift rear wheel over a bit with washers so that chain to rear wheel doesn't rub against the drive chain from the shifter jack shaft. You may have to experiment a bit with chain ring spacing too if you can't get spacing right so chains don't rub.
e. Chain tension. SBP has a great design that they have upgraded but in my opinion, they have gotten lazy or resistant to customer feedback, and have FAILED TO PROVIDE A SPRING LOADED CHAIN TENSIONER FOR THE CHAIN RING drive chain. SBP, please develop and provide this option. There are users here who have offered you their designs and for some reason you are resistant to adopting a chain tensioner. Original Poster, you'll get sick and tired of having to regularly stopping to tighten your drive chain because it stretches. It stretches constantly and it doesn't matter who much you spend on a chain, they all stretch. I carry all tools to loosen all mountain bolts so I can adjust chain tension on long rides.
f. You may need special tools to remove the pedal crank asssembly (bottom crank??)...not big on bike terminology. Use the widest sealed bottom crank that SBP uses, the stock one in the kit isn't wide enough if you use the bike I recommended. You'll probably need to shave a little width off of bike pedal arm too for it to clear.
G. Manual clutch: Get ride of it, the shifter kit works awesome with a centrifugal clutch. My centrifugal clutches have all been incredible and the only thing I've had to do, most recently after 3+ years, is to lube the bushing on the centrifugal clutch assembly.
That's about it, if you decide to go with the Schwinn Searcher, let me know and PM me, I can help you out over the phone and take pics of my two current searchers for you to view to help you out.
Good luck and you'll love it when it is done. BTW, the old Schwinn Searchers had a 34 tooth 1st gear and the one on the link doesn't. I swapped out my last build with the Mega range sprocket assembly that had a 34 tooth 1st gear, it really helps reduce clutch wear when starting out from a stop and is awesome on hill climbing.
