99 CR250 into 85 250r ATC? Good choice?

[dansvan]

Would it bring anything to the table compared to the original? I know it has a powervalve and better ignition. Larger carb stock. How do you think a pipe designed for the original non power valved motor would do? I have a chance to pick one up complete for 400$. Just wanted some input.

[CoeShow]

One thing you are forgetting is that the CR engine has no counter balancer in the engine like the ATC engine. You can fabricate the necessary mounts and all to physically install the CR engine, but I guarantee you will most likely NOT like the end results.

The vibration will be unbearable. In fact, it will be so severe that within a very short time mounts, exhaust pipe and frame tubes will form cracks. Every nut and bolt will vibrate loose in short order.

Many have performed this swap through the years so you will find numerous different opinions. We tested many CR engine conversions at Honda back in the mid 80's to learn this. I know the 250cc 2 stroke Yamahas and Kawasaki's never had counterbalancers, hence the significant difference in noticable vibration of those brands vs. the Honda's.

However, the frames on the Yamaha's and Kawasaki's were designed differently in an attempt to help quell engine vibration. Honda held many patents on 3 wheeler designs. My guess is that the counter balancer was one of them.

I recommend you steer clear of installing a CR engine. After significant time and modification, I feel you will be disappointed with the end result. Stick with the original engine.

Good luck and ride safely.

[YTM 225dx]

One thing you are forgetting is that the CR engine has no counter balancer in the engine like the ATC engine. You can fabricate the necessary mounts and all to physically install the CR engine, but I guarantee you will most likely NOT like the end results.

The vibration will be unbearable. In fact, it will be so severe that within a very short time mounts, exhaust pipe and frame tubes will form cracks. Every nut and bolt will vibrate loose in short order.

Many have performed this swap through the years so you will find numerous different opinions. We tested many CR engine conversions at Honda back in the mid 80's to learn this. I know the Yamahas and Kawasaki's never had counterbalancers, hence the significant difference in noticable vibration of those brands vs. the Honda's.

However, the frames on the Yamaha's and Kawasaki's were designed differently in an attempt to help quell engine vibration. Honda held many patents on 3 wheeler designs. My guess is that the counter balancer was one of them.

I recommend you steer clear of installing a CR engine. After significant time and modification, I feel you will be disappointed with the end result. Stick with the original engine.

Good luck and ride safely.


The yamaha trikes did come with counterbalancers in the engine. In fact the 225dx's came with a gear driven counterbalancer.just look on here http://www.files.3wheelerworld.com/Sads/yamaha225dx-page2.jpg This is an original ad and on there it says it has a gear driven counterbalancer

[Nick_R_23]

Is that the CR250 motor that was on CL?? That guy was gonna drop that motor into a Tecate 3, which is probably the only reason he couldve ever stood the vibration. If you really wanted to, you could probably fab up some rubber based motor mounts to seriously reduce vibration, along with rubber exhaust mounts. I personally would stick with a ATC motor because I think it makes more HP and is probably geared better then the CR motor is anyway.

-Nick :TrikesOwn

[BigReds Forever]

I think he was talking about the 2 strokes

[dansvan]

Why can they live in a motorcycle situation then? The vibes that is?

[Red Rider]

Why can they live in a motorcycle situation then? The vibes that is?People have been wondering that for years. Evidently it has something to do with the frame & suspension differences between a 2-wheeled motocross bike & a 3 or 4-wheeler. Comparing a CR250 bike to a 3 or 4-wheeler with a CR250 motor installed, the vibration will be way less on the CR250 bike.

[cr480r]

If you have the 250R engine then forget about about the CR engine... If you dont have a engine the CR sounds like a pretty good deal... It wont vibe much worse than the dirtbike... the only real difference is the fenders..

[200x Basket]

i wonder how many of the posters in this post have ridden a trike with a dirt bike engine? I bet NONE have.

[deathman53]

I have a quad with a dirtbike motor, crf450r, the gearing is way off, first gear is too high and 5th is too low. Bike transmittions are very different. I have read that the non-counterbalanced motors have a noticable vabration, but its not bad. Its when you install them in a quad, that it is really bad. If you have a 250r motor, stick with it. If you don't, well, then go for the cr motor. You might not be 100% happy with the end result, as many who put dirtbike and non-counterbalanced motors are. You will need to do something to make the kicker clear the frame and put on flip-top fenders or a stuppy kicker to be able to kick it. Mine has a kicker extension and a stubby kicker. My crf450r trike, will have both. For mx, like I do, I happen to like the dirtbike gearing, however for open trails and open riding, a worked atc250r will take me on open riding. I'll be in 5th gear and he'll go right past me, something to consider.

[Billy Golightly]

i wonder how many of the posters in this post have ridden a trike with a dirt bike engine? I bet NONE have.

I doubt Mike Coe is one to talk without knowing...:D

[TwoHundredEx]

I have a dirtbike engine in my 200X, and I didn't really notice a whole lot of difference in vibration from when it was in the bike.
It has caused a couple bolts to rattle loose on the frame like the seat latch bolt, and shock ressy mount, but it's definitely not unbareable.
I'm sure it doesn't vibrate as much as the CR would, but even then, I don't think it would be enough to stop me from riding it or dissapoint me.
With that being said, the only 250cc MX bike I've ridden was a '98 KX250, it didn't seem that bad, but for all I know the CR could vibrate like crazy.