Differences between years of cr500 motors?

[Tri-Z Pilot]

I should probably have posted this in the bike section, but seeing as how this is goin in a trike I figured I would check with the guys runnin them in their trikes.

First off, what years were the liquids? was it something like 85-92. I believe that I was reading that the 85-86 ones had more power, but lacked parts availability. I'm leaning more towards something with better parts supply as I'm sure that a couple ponies wont make that big a difference. Later years had scalloped ports or something to aid in easier starting, but I believe I will just go the route that Lou and Tim did with decomp releases and blaster kickers.

The big thing I want to know is were the motor mounts different for different years? I won a 250r chassis with a cr500 cradle grafted on through e-bay which is where I am starting my build. The motor that was in it was an 85, but I would rather use a later year due to better availability. Will a later year motor fit in an older frame?

Next is since the 250r uses the 500 cradle, pipe fitment will be a cinch, just need to re work the end where the stinger attaches. What would the best pipe be for bottom to mid power, or a good broad power pipe. The guy has an fmf gnarly that was already modded for the frame, are these decent torque pipes?

lastly since this is gonna be a woods bike (hence the q's about makin the motor more torquey). What is the smallest swinger that I should run? I received a +4 on the 250r I got today ( traded my car for it) and I seem to like it. not too long, not too short. Whats everyone runnin on theirs? I believe Kasey's is a +4?

[Louis Mielke]

Have you ever ridden a 500? Torque is not going to be a problem. You'll probably build it and then want to sell it because you wont want to ride it. Thats what usually happens. The number of people who have built a 500 is climbing but the number of people who ride one regularly is still very low.

All 500 engines have the same mounting pattern. They have not changed. 84-01 will all bolt into any year frame.

The 85 is the only year with a real parts availability issue but even this isn't as bad as most say. 87-01 all have the most parts interchangeability. The differences are very small.

Just go with that fmf you like it fine enough. The fmf has a little more low end torque but looses some top end.

Most run a minimum of a +4. I was running a +2 but I'm going to a stock 450r length very soon.

[Tri-Z Pilot]

Yeah Ive ridden one that was worked a little, but I'm not one for 2 wheels. I realy did like how torquey it was with the simplicity of a 2 stroke. For some reason I think they stopped production in the early 90's, guess I was thinkin of somethin else.
How does that blaster kicker set up work? still have to trim the fenders?

[Louis Mielke]

I've actually switched to a banshee kicker on my bike but I'm using the cr frame.
I have not had to trim the fenders, billy is using a blaster kicker on his atc conversion. maybe he can chime in.

[Billy Golightly]

Yeah, your gonna have to trim the fenders with pretty much any kicker using the ATC chassis unless you make a flip up seat or something. The 85-88 CR500 motors are considered first generation (Even though there are still specific differences between the years) and the 88-01 is considered second generation and differ greatly from the first ones. In an ATC chassis, using a first gen topend and sidecase makes routing the water hoses around the pipe a bit easier because of how they are configured.

I'm not so sure that fitting the pipe will be real easy for you, because you still have to fit around the gas tank, radiators, shrouds, and the back part of the engine crade where the silencer snakes in. I am personally not a fan of the FMF pipe at all. When I had my 500 setup in the drag chassis (All CR based instead of ATC) I ran the FMF, DG, and pro circuit. I actually liked the DG a lot better, but I was'nt looking at low end grunt either, it just felt to me like the fmf pipe really killed the revs. The DG was a good all around pipe and the pro circuit was exactly what I was looking for, for drags and it even worked better then the FTZ out frame.


And call me crazy, but my arm is stock length still, and I don't find it really necessary to extend it any.

[jeffatc250r]

If your planning on running it in the woods, i would keep the swinger stock length. I tried a plus 6 on my 500 and it sucked. Im much happier with a stock unit, the bike behaves better on corners than with a long-dong hangin out the back.

[Tri-Z Pilot]

The +4 swinger I got on the new R yesterday seems to turn pretty well in my opinion, I have yet to really test it in a woods enviroment though.

Since the R chassis utilizes a cr cradle, i was figuring pipe fitment wouldnt be too hard. The gnarly that dude used before was only tweaked where the the stinger attaches, but the chamber seemed slung pretty low across the right side of the motor. I guess different pipes will have different bends and routing. I suppose I could see about pickin up the gnarly fairly cheap, then goin from there if I dont like it.
So I suppose I should go with a first gen motor to make things fairly more simplified in the radiator plumbing department? Thats what everyone is running right now right?

[Bad Karma]

For simplicity with mounting and to retain the use of a 250R swingarm, you will probably want to go with the earlier engine (85-88) because the swingarm pivot bolt is the same diameter as the 250R. Later CR500 engines used a pivot bolt that is 2mm larger in diameter. Of course, anything can be made to fit with enough work...

[Tri-Z Pilot]

Thanks, this is the stuff I am lookin for. I guess first gen cr it is. Is it just me or are the 500 motors gettin to be fairly pricey?

[Bad Karma]

Sometimes it's cheaper to buy a whole bike instead of just the engine. I picked up my '85 CR500 for 500 bucks. The engine ran and was in pretty decent condition internally, but the rest of the bike needed a total resto.

Check out this site, http://cr500riders.com/cgi/yabb/YaBB.pl

You need to own a CR500 to register, but you can search the archives, and the tech forum has all the info you could ever want...