09-25-2017, 09:44 PM
mel,
external parts interchange pretty freely throughout the standard series motors.
internally there are some differences but you aren't planning on being an engine builder so for your purposes i'll skip that part if you don't mind.
as ted said you might have a mc6 crank and piston. you can also have just a thin ring piston.
neither hurts your motor except in duriability of rings but since we rarely run them that shouldn't be an issue.
the history is this,
mc5 was an ok motor. then the modifiers started in on them and added thin piston rings =faster motor. then stroker cranks were created. mcculloch was fast off the line and made thier own "stroker" kit.
then they released the mc6.
this all happened so fast that a ton of mc5's were in production when they redid specs. mccullochs solution was to cross out the mc5 and re-stamp them mc6.
then a new issue cropped up as the cheap mc6's were as fast as the super motor mc10. so mcculloch then stroked the ten eventually changing to mc20.
history over.
you have a fine motor.
easiest way to determine if you have a mc6 crank is look at counter wt' if there a line cut along the curve of the counter wt you have a mcculloch mc6 crank. if not it may be an old reweld so check the stroke as ter said also to see.
external parts interchange pretty freely throughout the standard series motors.
internally there are some differences but you aren't planning on being an engine builder so for your purposes i'll skip that part if you don't mind.
as ted said you might have a mc6 crank and piston. you can also have just a thin ring piston.
neither hurts your motor except in duriability of rings but since we rarely run them that shouldn't be an issue.
the history is this,
mc5 was an ok motor. then the modifiers started in on them and added thin piston rings =faster motor. then stroker cranks were created. mcculloch was fast off the line and made thier own "stroker" kit.
then they released the mc6.
this all happened so fast that a ton of mc5's were in production when they redid specs. mccullochs solution was to cross out the mc5 and re-stamp them mc6.
then a new issue cropped up as the cheap mc6's were as fast as the super motor mc10. so mcculloch then stroked the ten eventually changing to mc20.
history over.
you have a fine motor.
easiest way to determine if you have a mc6 crank is look at counter wt' if there a line cut along the curve of the counter wt you have a mcculloch mc6 crank. if not it may be an old reweld so check the stroke as ter said also to see.
Dave L.