BannedCR500Riders.com

I just bought a 1985 engine for the steelie I am building. I know I have to modify the rear bushing - no problem. I have some other questions about the engine:

1.) Does the later model inner clutch cover fit - I think it does but want to be sure.
2.) What other CDIs can be used - I think the 1999 CR250 works fine but again not sure - the CDI is with the motor but just for reference.
3.) What is the power delivery like? I heard these were really fast.
4.) Giving that I think the sleeve is thinner, how many times can the 85 cylinder be bored?

Thanks guys.

1) yes
2) i dunno what will work with the 85 stator i have a 92 stator/cdi on mine
3)It will deliver the goods
4)Mine was 2 over- I got two years of racing/practice out of it.
I just took the head apart and there was a crack on one half of the sleeve from the intake port. I think 2 over will work but you should keep an eye on it. Mine probably had 300-400 hrs on it.

1) you can press the inner gear from the 85 basket and use it in anything newer, the inner hub fits the shaft aswell, a bit of mixing, but you can get there and the newest covers made fit it too.
2) not sure, the 85 is even different than the 86, how many wires on the stator?
3) power delivers is rippy, the motor comes on fast and really lays down after 7000-7500 but can be made to go more. It might feel faster than it is.
4) the sleeve can go to 91mm, the sleeve is thinner, but its not going to be a problem.

Have a look thru my tech link at the bottom of my posts, theres diagrams of parts that can be swapped. The most convinient thing is changing the outputshaft to an 87+ so the sprocket availability isnt a problem.

Roostius_Maximus wrote:1) you can press the inner gear from the 85 basket and use it in anything newer, the inner hub fits the shaft aswell, a bit of mixing, but you can get there and the newest covers made fit it too.
2) not sure, the 85 is even different than the 86, how many wires on the stator?
3) power delivers is rippy, the motor comes on fast and really lays down after 7000-7500 but can be made to go more. It might feel faster than it is.
4) the sleeve can go to 91mm, the sleeve is thinner, but its not going to be a problem.

Have a look thru my tech link at the bottom of my posts, theres diagrams of parts that can be swapped. The most convinient thing is changing the outputshaft to an 87+ so the sprocket availability isnt a problem.

Thanks - the engine is still in transit to me so I cannot check the stator wires. Does the kicker from the newer model fit? As well are you saying the front sprocket on the 1985 is different than the 1989+ models? I heard about the back off of power so I figured a Gnarly may be a bad choice. I am thinking PWK 39.5, RAD valve and Pro Circuit pipe and 304 silencer.

Roostius_Maximus wrote:1) you can press the inner gear from the 85 basket and use it in anything newer, the inner hub fits the shaft aswell, a bit of mixing, but you can get there and the newest covers made fit it too.
2) not sure, the 85 is even different than the 86, how many wires on the stator?
3) power delivers is rippy, the motor comes on fast and really lays down after 7000-7500 but can be made to go more. It might feel faster than it is.
4) the sleeve can go to 91mm, the sleeve is thinner, but its not going to be a problem.

Have a look thru my tech link at the bottom of my posts, theres diagrams of parts that can be swapped. The most convinient thing is changing the outputshaft to an 87+ so the sprocket availability isnt a problem.

I can see what you mean by the sprocket difference. There seems to be no shortage of the 1985 sprockets available on eBay or Dennis Kirk though.

Kicker fits the splines yes, where it rests might be a different story. Some of those older engines have a coarse tooth kicker spindle so they enguage at a different spot. I'm sure you can swing the stopper over internally to set it where you need, but it should work as is.

sprockets on the 84-85 are 6 spline, 86-87 are 11 and 89-01 are 17
the shaft can be changed with the 11 spline no problem, it takes a bearing in the case a couple of washers and a 2nd gear to use the 88+ shaft in the old stuff. i might have it all if needed.

Go Gnarly

Pwk is good

Reeds, i'd get a VF2 for a 1989+ engine, its shorter, trust me on this, Or run a 89+ stock cage with the reeds like dubious has in his engine thread and use an 87-88 reed boot if you have a mint one or find one cheap. The 89-01 boot will fit, its longer and will work no problem in a steelie chassis, but in an AF stacks up the carb too close to the spring and forces the boot out against the chassis.

Roostius_Maximus wrote:Kicker fits the splines yes, where it rests might be a different story. Some of those older engines have a coarse tooth kicker spindle so they enguage at a different spot. I'm sure you can swing the stopper over internally to set it where you need, but it should work as is.

sprockets on the 84-85 are 6 spline, 86-87 are 11 and 89-01 are 17
the shaft can be changed with the 11 spline no problem, it takes a bearing in the case a couple of washers and a 2nd gear to use the 88+ shaft in the old stuff. i might have it all if needed.

Go Gnarly

Pwk is good

Reeds, i'd get a VF2 for a 1989+ engine, its shorter, trust me on this, Or run a 89+ stock cage with the reeds like dubious has in his engine thread and use an 87-88 reed boot if you have a mint one or find one cheap. The 89-01 boot will fit, its longer and will work no problem in a steelie chassis, but in an AF stacks up the carb too close to the spring and forces the boot out against the chassis.

Is there any reason you said VF2 over say VF3? Will the 1985 boot fit (reach) when I install the engine in a 1997 steelie frame?

the 85-86 boot is an angle that only matches the airbox of those years.
the VF2 is shorter and i prefer it over the 3, I'd chose a 89+ stock cage but ported over anything else

Roostius_Maximus wrote:the 85-86 boot is an angle that only matches the airbox of those years.
the VF2 is shorter and i prefer it over the 3, I'd chose a 89+ stock cage but ported over anything else

So the 89+ stock cage and intake should boot right on then - perfect I will pick one up. I kinda thought Ngarly would further kill the top end since it is a "bottom - mid" pipe or so I have heard. I think I will go a tooth or two lower on rear - perhaps 14 / 48 gearing.

the gnarly will have more torque down low than the pc, its probable that a stock motor geared to use the tq would be faster and smoother than a stock motor geared to rpm the pc pipe

later stocker pipe is a perfect match with the short rod motors

nmdesertrider wrote:later stocker pipe is a perfect match with the short rod motors

The problem with that is I want a pipe in excellent shape and I am not going to pay a fortune for OEM.

CR500PHIL wrote: The problem with that is I want a pipe in excellent shape and I am not going to pay a fortune for OEM.

Bob would probably sell you one of his for a "small" fortune.

Roostius_Maximus wrote:Kicker fits the splines yes, where it rests might be a different story. Some of those older engines have a coarse tooth kicker spindle so they enguage at a different spot. I'm sure you can swing the stopper over internally to set it where you need, but it should work as is.

sprockets on the 84-85 are 6 spline, 86-87 are 11 and 89-01 are 17
the shaft can be changed with the 11 spline no problem, it takes a bearing in the case a couple of washers and a 2nd gear to use the 88+ shaft in the old stuff. i might have it all if needed.

Go Gnarly

Pwk is good

Reeds, i'd get a VF2 for a 1989+ engine, its shorter, trust me on this, Or run a 89+ stock cage with the reeds like dubious has in his engine thread and use an 87-88 reed boot if you have a mint one or find one cheap. The 89-01 boot will fit, its longer and will work no problem in a steelie chassis, but in an AF stacks up the carb too close to the spring and forces the boot out against the chassis.

Why do you prefer the vForce over the Rad valve? I was thinking Rad valve because since I have to buy a new intake (cannot find any used ones in excellent shape) and a gasket kit and a vForce it would be easier and cheaper to get the Rad valve. I have used vForce on a few bikes but never Rad valve. As well my reasoning was that since apparently the RAD enhances the top end and the 85 500 is shorter on top end it may be a good match.

In the 89+ motors I'd run the 89+ reed cages i modify and a 3/8 spacer, if not those, the VF2
In the 88 or older id run the 89+ cage without a spacer, or the vf2.

Roostius_Maximus wrote:In the 89+ motors I'd run the 89+ reed cages i modify and a 3/8 spacer, if not those, the VF2
In the 88 or older id run the 89+ cage without a spacer, or the vf2.

Do you know of anyone selling an 89+ intake and or cage in great shape?

I dont have anything, actually i need another myself.
Artimous might have one in the shoppers section tho

Any good YZ250 will eat that motor up, everyone knows that.

http://cr500riders.com/cgi/yabb/YaBB.pl ... 318429/all

seanmx57 wrote:Any good YZ250 will eat that motor up, everyone knows that.

http://cr500riders.com/cgi/yabb/YaBB.pl ... 318429/all

If you are referring to a previous post then we have long since estabished that that particular CR500 bike was shit hauled - time to move on. I am sorry I had to learn about these bikes and was not born with some innate knowledge about CR500s. And you know what - a 2011 YZ250 with the right rider would give it a good run for the money I am sure. :

A good rider will beat a CR500 on a 125 if we are talking about MX or woods riding.

what was wrong with the other motor?