Well.. i got the 83 engine in the beater! Now that it is running, I Love It! i have no idea how much RPM change it has because the 83 has no place for a tach cable and i'm not going to change the drive unit until i get a new gasket, i had enough oil on my right boot from the old seal leaking from all the blo-by of the old engine. The 83 had rust in both left cyl intake ports with rust on the valves so i ran a compression check the 2 left cyls dry were 60 and 75lbs, the 2 right cyls were 155 and 165 dry. I put 3 oz's trans fluid in each of the cyl's, put plugs in it and spun it over for about 30 seconds,pulled the plugs and spun it to clear the cyls of oil. Then ran another test. 2 left cyls were 140&155 and both right cyl's were 175 so i put it in the beater after a valve adj and belts prior to the compression test. Bolted everything up,hit the button and no start?? Turned over fine but no spark? BALLS!!!! that is all i could say after i changed everything except the pick up units(or what ever honda calls them) so back out comes the engine so i can change the pick up's from my old 80 engine(both engine's had good vacume adv units) did the swap,reinstalled the engine and it lit right up but ran like it needed a tune up? well it had new plugs so i figured it needed to have the crap ran out of it from the rust in the 2 left cyl's.. away i go.. Man, what a great gearing difference the 83 engine is for a naked beater.. 75mph and it didn't sound like it was trying to kick parts out but in netural at guessing 3to4000 rpm it was barbling like the timing is too far advanced? I wouldn't think the timing changed with the pick up's being changed as it has no adjustment? any way,i unplugged the vacume advance hose,plugged it and it runs ok, not perfect but ok. No way in hell i'm going to remove the engine again to set the timing. Tomorrow i'll check gas milage and ride her till she drop's... Mabey with a engine with cylinder pressure i can play with jetting in the carter/webber? My plugs looked good in the tired engine but it feels lean with this one :wave: