PDA

View Full Version : Anyone experienced with engines....CR480 questions



TheRealFatShady
05-10-2010, 07:57 PM
I have a 1982 CR480, first owner said low compression. (Won't start with carb spray directly into cylinder)

I found a complete 82 engine, that the guy will sell me with a good usable top end. It has a compression release. Did any stock ones come with this, or is this a machinists' custom work? I had some trouble kicking my old racing YZ250, this will be a lot more I'd expect.

Also, what do I need to make my 82 4 speed into an 83 5 speed?

I found this:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=120568065259&viewitem=&_trkparms=clkid%3D8626032813849347344

But won't I need more? Hopefully someone here can tell me....without just buying that, lol!

Thanks

RIDE-RED 250r
05-11-2010, 09:00 AM
my brother had ann 83 cr480 some years back, i dont recall it having a decompression system of any kind on it. and as to converting your 4 speed into a five speed, i wouldnt try messing with the inards of your tranny. along with that shift tower, you would have to swap out the entire inner workings of the transmission, ie: gears, gear shafts, and probably shift forks. (obviously you will have to get another pair of gears in there for the 5th gear). i am not sure if even that would be possible due to possible differences in the crankcases. just be careful of what some parts jockey on ebay advertises. they dont always know exactly what they are talking about. freshen up your topend with a new piston and fresh bore job (so long as the bore is not already maxxed out) and enjoy it for what it is...having riden my brothers 83 cr480, and owning an 89 cr500 myself, trust me, you arent going to miss that 5th gear too much. in fact, i would wager that the final ratio is probably very similar between your 4 speed and the newer 5 speed units. you will just have more room to wind up in between shifts...

TheRealFatShady
05-11-2010, 10:14 AM
Thanks for the info, that cylinder I found looks good. $100 for that w/ custom compression release + wiseco piston and rings. A bore on my old cylinder alone is around $60, so I'm going to get that. Ideally I'd like to have to top ends that I can swap dependent on what I will be riding.

And the guy with the transmission parts has been VERY helpful. We've chatted already a few times via ebay messages. I guess he builds and restores the old 480 and 500 CR's. Said it's a hell of a job to swap, need those parts + tranny (gears) itself, but it can be done. I may just hold out and hope to find an 83 bottom end eventually, so that I can have a racing engine and a slightly more user friendly one.

Going to pick up that top end + a gasket set. Going to tear into my engine this week.

fabiodriven
05-11-2010, 11:28 AM
Shady, I would love to build one of these. I hope it all comes out well. I'd love to go riding with you once it's done. Good luck man!

TheRealFatShady
05-11-2010, 11:39 AM
Sure, we're not far away. I'm also in Falmouth/Cape Cod in the summers, if you ever go near there.

I must warn you, it may be awhile before it *looks* pretty, but it will run good.

RIDE-RED 250r
05-11-2010, 12:43 PM
ah well good then. sounds like you got it figured out. good plan, having 2 topends, or any other spare parts you can get your hands on for the ol 480 is a good idea in my book. they didnt have a real long prod run, plus they are getting quite dated.....