Hi I have the bike and did a install about 2 weeks ago with a 49cc 2 stroke China girl
I don't know what a "front mount kit" is so I don't know if you need to order one or not.
But yes I had a problem with the front mount because the frame tube on the Landmark is to big around and will not fit between the two studs that come out of the front of engine, I made a set up that works for me using a car muffler clamp and a piece of 1/2" square tubing I just had to drill 4 holes in the square tubing, no welding.
I will check to see if I made pics of the set up or not I will show you what it "might look like"
The rear engine mount works perfect that comes with the engine, the other problem I had was mounting the chain tensioner, the bar it mounts on is too small so you can't tighten it down enough and it wants to turn in toward the wheel when under tension, after one badly bent wheel, so I did away with the tensioner by shorting the chain so when I need to take the chain off I just remove the master link on the chain. Check other threads for fixes if you want to keep the tensioner on, just don't put it on out of the box it will cost you a wheel.
I will get back to you here.
inch and a half sounds about right. my scwhinn del mar has the same size frame.
the tab on my front fender broke(drilled out ribbet and added metal L plate and bolt)
replaced stock kickstand with a adjustable heavy duty kickstand from walmart(goes in stock location).
got a flat tire on the rear(changed intertube,keep patches and glue and airpump with you and you can slide tube out while wheel is on bike and patch and put air in,good to go)if not it will be hard to walk to home since these tires when flat come right off the rim. when i got the flat i didnt have anything and walked it 1/2mile home and tire can off rim and i had to plastic tie the tire on the rim just to get it home.
tensioner does not stay tight and wants to go into the wheel,i put the tensioner on tight and layed a bolt like this ( I----- ) behind the bottom of tensioner and added a hose clamp on each end of the bolt to hold bolt to frame and this keeps the tensioner from moving.
besides that the engine went on great.
Perkoff
That front frame post on mine measures 1.515" so just a little over 1 1/2".
To add to the other replys, I had some knoby off road type tires from my mountain bike that I changed out with the stock tires that come with the Landmark that made a major improvment in handleing, also while it was apart I went to Walmart and they have solid rubber inner tubes for less that $20 those went in and now I don't have flats at all. Well worth $20 each.