Ill fitting crank / pedal threads

Dear Forumengers,
Some advice please:

My MSK Sylvan pedals don't screw easily into the used 170mm Shimano 600 cranks that I've just bought. I've managed to get them in a couple of turns is all.

I haven't measured the threads, I'd presumed that they would be the same, but I'm worried now in case I've forced and stripped the beginning of the thread.

Any thoughts? I'd be very grateful.

grease the bitch up. Screw her the right way, start gentle, don't force it.

i've had this problem recently with look keo classic pedals :(
they fit onto my alloy cranks with a bit of effort. but not onto
the new chorus carbon cranks.. i'm a little bit annoyed about that..

the speedplay pedals go on easily by hand on both set of cranks..
probably a different issue to benny's

plenty of grease is essential,
check to ensure you have the correct pedal on the right side..
and a decent pedal spanner.

Lol @Tenderloin, the irony
I've tried, even with grease can't get it in... like trying to get a marshmallow into a piggy bank.

Cheers Alma, ill try with some other pedals and see what happens.

Nope. No good. Right side in but hard work.
I've taken a de-burring tool to the edge of the left crank thread, still won't fit in.
Next, re-tap the crank and see if that works. Otherwise I'm going to smash the fcuker to pieces with a lump hammer.

It worked. BOTR.

same issue as almac68 with look speed play's. My old pedals remove and go back on easily but these new look keo's wont go on!

what is re-tapping? expensive?

http://www.chainreactioncycles.com/Models.aspx?ModelID=55945
two of these, one for each side. Makes fitting pedals a breeze, screw them all the way in with your fingers, then tighten the last 1/2 turn with a spanner