i have a 1983 fxrs with a shovell head motor,i have noticed an amount of  smoke from rear cylinder exhaust when i rev engine back of and rev again is this caused by the valve guide seals or something more sinister.thanks for any imput.

hey kimbo,havent done a compression test lately i was told that this model shovell are low comp motors,when i did comp test it was around 82psi.

i think,     if you are going to pull the head you realy should re fit-up the hole top-end ,     pull the barrels off & do the lot as these are older motors  that a freshen up would not hurt  you would not just do the heads & not re ring it @ least  you never know what you might find

smoke is blue and only does it after throtle on and then shut off and throttle on then blue smoke which clears,think i will pull down and freshen up top end,can you just rering or do i need to bore out and fit pistons as well,will do up heads to,im new with harleys so still learning about them,thanks for info.