250R questions

[freak400]

1- Will a 88-89 motor bolt right into a 86-87 frame???

2- Anybody know if a CR500 engine bolts in??? I have seen them in there, just dont know if the frame is Modified to fit

[troybilt]

check out the hybrid section for the cr500 questions...

[bushwesl]

1- Yes, all years interchange (86-89 TRX, 85-86 ATC).
2- No way.

[Qracer]

The 88-89 engine will fit into the 86-87 chassis. As will the 85-86 trike motors.( Engine mounting holes are in the same place on all of the liquid cooled ATC & TRX 250 motors)
The CR500 is not a bolt in engine. You will need to fabricate motor mounts & modify a pipe to fit. I hope you are a good welder, the vibes from the motor will crack the frame.

[freak400]

So you have to fabricate motor mounts, but does it bolt into the rear of the frame thru the swingarm?? I have a 250r frame that I am looking at that used to have a 500 in it. Just wondering if that was widened or anything like that.

[troybilt]

...not too mention rattle your brain loose too... There is no counter-balancer in the CR motor. ....many have tried to come up with a solution, many have failed... you're best bet is to talk to someone on here with a 370PV or 400 motor, those will prolly smoke a cr500 anyway, and without the vibe issues. :eek2:

[Iliketogofast]

Using urethane or rubber motor mounts solve the problem I thought on the vibration issue...?

[troybilt]

I heard it helps. Also heard rubber handlebar clamps, etc... Sounds great, and I looked into it seriously for awhile. Being an engineer thought it sounded like a great challenge, I've researched, WR500, KX500, CR480, all had vibration issues. Most of the people I've talked to that done the conversion would never do it again. I'm still looking into the project, just haven't heard many positive things, so far. I'd love to hear from someone that actually enjoyed riding the bike with the conversion.

[Iliketogofast]

A more expensive option would be to go with the Sabertooth cylinder, and there wouldn't be any vibration. But it would be expensive. You have to use their crank and get your cases modded and everything, plus you have to buy the reeds and the carb and the pipe and everything else or it won't run right.

[troybilt]

Yeah, that's the one I was thinking of, couldn't remember the name. its something like 3500 bucks, don't they mod the cases to mount a CR500 jug to it? Anybody on here have one?

[Iliketogofast]

It's actually a completely custom cylinder with their portwork and everything. It isn't a CR500 one, but I bet that kind of a setup is available or out there.

I've heard that the CR500 jug of certain years almost bolts right on.

[xlr810]

Here's the motor I'd like to see in a quad. It is 700cc. I have no idea if it runs a counterbalance, but it is 70 horsepower and 50ft/lb torque stock. I can fit my fist into the cylinder. I ran across this at the Indy Expo this spring...

http://i192.photobucket.com/albums/z241/mjmisek/Dealer%20Expo%202008/DSCN1050.jpg


Here it is in the bike. I'm not a huge fan of the unfinished casting, but... I'd still like to ride it...



http://i192.photobucket.com/albums/z241/mjmisek/Dealer%20Expo%202008/DSCN1049.jpg

[my88r]

do a search on a cr 500 motor in a r frame. very beat to death topic. :scary:

[Iliketogofast]

That's the Maico/ATK Intimidator. Pretty badass IMO. It probably not counterbalanced though, and while I've never experienced firsthand the CR500 motor, I'm sure this is much worse.

It would be nice to see in a Cannondale frame or a 250R frame if it would fit, but the vibration would have to be worked out first.

[Buttermilk]

www.cpindinc.com is making some really neat cylinders for the 250R.

As already mentioned, they make the Sabertooth. They also have a Sphinx cylinder and the latest one is the Puma.

Sabertooth is the biggest cat, while the Puma is the middle cat and the Sphinx is the smallest cat.

All designed to be used with the 250R bottom end (with some modification of course for the bigger versions).

Sabertooths are in the 100 HP range when correct components are used. Pumas are reportedly right at the 90 HP mark on alky with correct components. I have a buddy who's got the Sphinx, but hasn't made it to the dyno yet.

I'd personally go this route instead of a CR500.