Yamaha Tri moto 200E with rev

[troy]

Hey, I need or going to need some help. Let me try to bring you up to speed here. the bike i own is well the title says it all, 1985 Yamaha tri moto 200E ,shaft and rev. The story goes like this, about 6 months ago the exhaust pipe up by the engine started to leak, which cause major backfiring. so i by some luck found a used but in good shape replacement. but heres where the trouble started, the bolts holding the old exhaust on snaped off, no matter how much heat was placed to it, it just wouldn't come out. so i put that subject on hole to work on problem number two, trying to get the old flange out of the head ( remember the pipe broke off up by the engine). I have no idea how or what was use to put it in but this was some thing else to get out. So out comes the cold cuts. after about 2 hours of gental beating i got it. Back to the first problem trying to get the bolts out. Of course the bolts where broke off where no tool could get at it. So i tryed bolt extracters, Half way there and the extracer broke off in the head, So out comes the drill bit to drill new holes, And of course they broke off to:( ..So worst came to worst i use self tapping bolts.

Today i notice that my work (which was expected) started to come up done. I have no way of putting new bolts in, no room to drill new holes, no nothing. I DO by luck have a used spare head here that i can use. What i need help with is setting the timing and all the good stuff that i need to know..lol....please keep in mind i'v only worked with 2 stoke engines never a 4.

So any input on this would be great before i screw this up anymore...

P.S the other reason i want to go a head and do this changing of the head now if because the top and bottom gaskets are leaking oil badly