Predator 212 into Dirt Bike?

[doesgo]

I've built a couple off-road karts, but never a minibike. While toying with the idea, I remembered I have a complete '81 Honda XR200R (4-stroke) with a buggered engine.

Would it be reasonable to consider mating a Predator 212cc engine to the motorcycle?

The upsides are the bike is complete and Predators are cheap. The challenges, I imagine, would include accommodating the swing arm and the lack of a multi-speed transmission. The 212 is fairly powerful, but surely a single-speed 212 would be down on performance compared to the stock 200cc engine with a 5-speed. I'm afraid I'd put a lot of time and effort into this and be disappointed with the result.

Any thoughts?

 

[Ebrownie]

Well, the xr definetely has more power than the predator, and the aforementioned lack of transmission. The only feasible way I see it working is a TC, then a massive sprocket ratio. Because a bike's final ratio is maybe only 3.5:1, but it also has an initial reduction in the integrated gearbox that is before the transmission. So you would need like an 80t sprocket on the back for it to work. (I didn't do any math, that's just speculation)

What you should do is either get another dirt bike engine, or get a Lifan. I think (?) they make a Lifan 200cc.

 

[doesgo]

Okay, thanks very much for the insight. I wasn't even aware of the Lifan. Pretty cool you can buy a brand-new engine with 5-speed on the aftermarket!

It's not worth it to me to spend $600 to resurrect this old dirt bike, however, so I think I'll abandon the project.

 

[ultralight01]

600?

The lifans are about 250.

 

[doesgo]

$250? Wow. I saw a couple 200cc Lifans on eBay and one other place and both were $400 plus about $100 shipping, and neither included ignition and....something else. The missing pieces added up to another $100.

 

[mckutzy]

I'd like to see links on that...

I agree... The motor might be cheap... But all the stuff to run it isn't there with it... Why they sell all that seperate I have no idea..

 

[doesgo]

I might be able to use the carb and ignition from my existing engine, I suppose. Still starts at $~500 delivered, though.

eBay Link

Another eBay Link

Amazon Link

 

[ultralight01]

Sorry, I didn't read the part about 200CCS. Hehe...
125cc engines are $250. And the lifans are insanely powerful for their displacement. They get going past 60mph, with a ton of torque. If fact, first and second are useless with gearing for 60mph, you could take off in third on the bike we had it on. So more speed is quite achievable. But you want the torque for a dirt bike.

Three examples (One is full auto, rest are 4-up)
http://www.ebay.com/itm/125CC-FULLY...ash=item256c6f0a36:g:isUAAOSwT6pVruHw&vxp=mtr
http://www.ebay.com/itm/4-UP-LIFAN-...m56422d6f59:m:maFrQENxRv07o79PMaq8cJg&vxp=mtr
http://www.ebay.com/itm/125cc-Engin...ash=item2a7b264eaf:g:o~YAAOSwLEtYmVcV&vxp=mtr

It'll bolt in without much work. But these are horizontal engines, not vertical like what was in the 81 xr200.

 

[itsid]

Search this site for "the Impaler" and you see what a predator on a dirtbike will look like
and get an overall idea.

that being said:
you will be disappointed in regards to performance for sure,
it will not be particularly fast nor powerfull..
a nice cruiser sure, but nothing like a dirtbike though.

Frankly, best and maybe not even most expensive would be to just revive the original engine (or get a original replacement engine)

'sid

 

[Ebrownie]

Frankly, best and maybe not even most expensive would be to just revive the original engine (or get a original replacement engine)

'sid

This is why I am a two stroke guy. if it was a 2 smoker, you could rebuild it for a couple hundred bucks tops... anyway, we never asked; what exactly is wrong with the engine that's in the bike?

 

[ironbutt]

You originally wanted to build a mini bike right? So go ahead and out the Predator 212 into the dirt bike roller and have a really cool mini with suspension and dirt tires.

Why worry about whether you will have the performance range of the previous dirt bike motor and transmission.

With a little experimenting of the sprocket sizes you can get a good compromise between low end torque and upper speed.

Have fun with it. Better than letting the dead dirt bike dust and rust without use.

 

[doesgo]

"Why worry about whether you will have the performance range of the previous dirt bike motor and transmission."

Because it was fun when stock, but by no means overpowered. Taking that down significantly would take away a lot of the fun. My hope was to get this Honda running and build a minibike for my son so we could ride together. I already built two karts for us, and this seemed like a good next step.

What's wrong with the bike? The kickstarter. Apparently, this is a fairly common problem with these engines, and the problem is internal, like split-the-case internal. I've read it's a 5-8 hour job for a professional and this bike isn't worth the investment, even if I could afford it. And I have no experience with these engines, either, so I don't want to tackle it from a knowledge or time standpoint.

"So go ahead and out the Predator 212 into the dirt bike roller and have a really cool mini with suspension and dirt tires."

I have to admit, it does sound kind of fun...

 

[doesgo]

Search this site for "the Impaler" and you see what a predator on a dirtbike will look like
and get an overall idea.

Thanks for mentioning The Impaler. I had seen it but not looked at it too closely. I just went through the entire thread and it's quite fascinating! I'm not as young as I used to be (47 now), and I'm not sure I need to cruise around at 55+ mph on a dirt bike anymore. Maybe a Predator-powered bike will be fun enough. I'm definitely considering this option.

 

[Hellion]

Fix the Honda's engine.

Putting any kind of industrial engine in a bike is silly and a waste of time while the kick starter issue seems like a simple issue (but a complicated fix).

These older Honda thumpers are getting harder to find in good condition. If you did a resto-mod on it, I think you'd come out ahead.


Where do you live, man? I might like an XR200R added to the stable...

 

[Flyinhillbilly]

Tear into it and try to fix the kick starter. It already doesn't work so I see no harm in it, plus you can learn something. If nothing else you end up
With parts to make junk art out of. Just take pictures as you go and put all the parts in clearly labeled ziplock bags. I know you can do it.

 

[Ebrownie]

Or you can just start it by rolling it and dropping the clutch. It's kind of a pain but if the engine still runs good it would be ok I think.

 

[doesgo]

...the kick starter issue seems like a simple issue (but a complicated fix).

Well said. I just looked through my old Clymer's manual and holy crap, that engine will be down to nothing by the time I can get deep enough to even inspect the kickstarter!

Where do you live, man? I might like an XR200R added to the stable...

I'm in Minnesota, and definitely not quite ready to let this machine go! Especially after seeing that great image you posted. I bought it for $100 from a friend around 1993 and it's been a 6-weekends-per-year machine at the cabin, but always been fun until I started having problems about eight years ago.

Tear into it and try to fix the kick starter. It already doesn't work so I see no harm in it, plus you can learn something. If nothing else you end up
With parts to make junk art out of. Just take pictures as you go and put all the parts in clearly labeled ziplock bags. I know you can do it.

I had that realization today as well. Might as well try to fix it. No harm in it, and I'll definitely learn something even if it doesn't work out. And yay for junk art! I've already got some small-block Chevy parts and R/C nitro engines on my shelf at work. Adding some motorcycle engine parts wouldn't be all bad.

Or you can just start it by rolling it and dropping the clutch. It's kind of a pain but if the engine still runs good it would be ok I think.

I don't want to do that long-term, especially with such a tall bike, but that's a great way to test it out to see if it even runs after all these years in storage. Good call!

 

[Hellion]

Might try another forum for specific help on the rebuild. Thumpertalk comes to mind.

https://www.thumpertalk.com/forums/forum/47-vintage/
http://forum1.aimoo.com/XLBoard Has an XR section.
http://www.xrv.org.uk/forums/xr/

 

[Ebrownie]

May I ask what part of Minnesota you are in? Just out of curiosity, because I have relatives in the Minneapolis area and also around glenwood.

 

[doesgo]

Might try another forum for specific help on the rebuild. Thumpertalk comes to mind.

Thanks for the links! I'll definitely check them out. What defines a "Thumper?"

May I ask what part of Minnesota you are in? Just out of curiosity, because I have relatives in the Minneapolis area and also around glenwood.

What a coincidence, I'm in the NW suburbs of Minneapolis...but I'd rather be in western Montana.