thanks for all the info. Are you happy with the IRK? Are there any cons to it? I like the sound of option "A" also. Thanks alot Dennisthorwarrior915 said:did it with an early 80's. here we go...
The taper for the flywheel (where the keway is) is different between 6V motors and 12V motors. Your 79 model is a 6V points ignition motor. To my knowledge, IRK's for the 6V cranks are not readily available... however one of the hardcore tuning companies from overseas may make something. I went the ebay route. Here is what you will need to do
-Browse ebay for a crank adapter that will change the taper of the crank from the 6V style to the 12V style. They are out there.
-Pick up an inner rotor. I would suggest grabbing one from Mark at AHP minis... thats where I got mine and it hasn't skipped a beat, plus its simple to install. Dont forget a new 12V coil!
-Get a flywheel puller too (grab it from mark when you order the IRK)
-Pull your stock flywheel and stator plate off. Make sure to use an impact driver on the #3 phillips head screws on the stator or they will strip out. Also, dont lose the little O-rings that go behind the screws on the stator plate... dont remember if it came with new ones or not. Install the new IRK stator plate and rotor (little flywheel) with the crank adapter in place. Mount your IRK cdi box, and new 12V coil that you bought seperately. Wire it up and rev away.
-Buy an OEM XR/CRF50 crank from honda, or out of the classifieds here... or an aftermarket stock style crank from DRatv.com. Because of the year of your motor, you will need an XR/CRF50 piston kit, and head to get the right deck height/dome/compression ratio. Sounds scary, but you can pick up somebody's stock engine parts for dirt cheap after they do a race head big bore kit install.
-Get yourself a complete gasket kit while you are at it.
-Split the cases and swap cranks, then put it all back together with new gaskets and top end.
-Any inner rotor will simply bolt on to the crank now with no adapter, and your motor will be completely fresh and worthy of performance goodies. Not to mention you got rid of the junk points!
I opted for choice A because I was feeling cheap... but its up to you.
thorwarrior915 said:So firepower... the way I see it, If he ran an 82-87 piston with his 79 head and an XR/CRF crank... it would be super low on compression because the old heads had some super dome going on? Maybe I'm misinterpreting what you said...
firepower354 said:Likely, but an early piston will stick 3mm out of the top of the jug. Swapping a 6v rod on to the 12v crank is about $65
ryan's dad said:thanks for all the info. Are you happy with the IRK? Are there any cons to it? I like the sound of option "A" also. Thanks alot Dennis
firepower354 said:I thought the 82-87 chamber was the same as the 81-back, but I dunno... ThongWarrior says no
OLDSCHOOL said:my opinion and experiance.. (I run a IRK in my stocker)
Since its going to cost you way to much money to convert over and you will not see any Preformance gain (2-stroke rev effect) or quick throttle responce.
Have your Flywheel proffesionaly Lightend as much material as can possibly be removed...and keep it safe ( up to -10oz) of material removed ($45.00 and $60.00)
you will get close to the same effect that the IRK is going to give you without losing any momentum in the corners
thorwarrior915 said:Sounds like somebody has their panties in a bunch.:lol: I double checked my thoughts on DRATV and they say 81 and back had the "old 50 dome"/short rod combo. 82-up has "new 50 dome".
By the way firepower WTF IS IN YOUR AVATAR???? I stare at it from time to time and cant figure out if its a pile of naked women, or some kind of abstract art... Like a barbie assembly line blew up and they melted into a pile of arms and heads???