best motor to swap into a blaster

mud runner

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Jan 19, 2012
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leabnon TN
we have a extra blaster frame but we dont have a motor and we got to looking and if were gonna spend the $800 + to buy a motor we might as well buy somtheing that has a little more power and just wondering what would have the best gear ratio for a atv
 
a blaster engine!

It's hard to find something with more power, small size, and a good gear ratio. About the best you're going to find to fit that bill is a WR250 engine and it still doesn't have a balancer shaft (or options for a bolt in pipe or anything)
 
a blaster engine!

It's hard to find something with more power, small size, and a good gear ratio. About the best you're going to find to fit that bill is a WR250 engine and it still doesn't have a balancer shaft (or options for a bolt in pipe or anything)

well i was thinking of maby a yz 250 or rm250 or kx250 or sompthing like that
 
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The WR250 is a dirtbike engine but it has a wider spread gearbox and a lighting coil.

The dirtbike engines are geared awfully high and are tuned to be "peakier" than a blaster engine.
 
the YZ240 needs frame fabbing to fit, the only thing that sorta bolts in is the DT200/wr200 motor but you not gaining that much. Best has put a KTM 250 in his blaster but again, frame fabbing etc is required
 
any 250 motocross motor could be made to fit, and my old man (BEST) has the cleanest setup iv seen using his ktm300. a blaster motor with mild work done to it can make for a sweet rig, lightweight and peppy. if that wr200 for a 1000 bucks is from the mid to late 1980's then id consider it. these motors are the same as dt200 motor there a pretty sweet setup, i run one atm in my bike and with a good pipe and goods these sound very similer to the motocross engines. i can keep up with the old man all day, altho drag racing side to side u can really notice his extra 100cc's
 
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any 250 motocross motor could be made to fit, and my old man (BEST) has the cleanest setup iv seen using his ktm300. a blaster motor with mild work done to it can make for a sweet rig, lightweight and peppy. if that wr200 for a 1000 bucks is from the mid to late 1980's then id consider it. these motors are the same as dt200 motor there a pretty sweet setup, i run one atm in my bike and with a good pipe and goods these sound very similer to the motocross engines. i can keep up with the old man all day, altho drag racing side to side u can really notice his extra 100cc's


"Keep up with the old man all day" Ha! Just 'cuz I let ya!
If I opened her up for anything more than just a few seconds, I'd be all alone in the woods!
(stand back for a Canadian hockey style family knock down. Careful where you place your odds, he is taller, but I bite!)

Seriously, it is a 250 not a 300, only 50cc larger. And Neil's riding skill do tend to keep him snapping at my heels. I considered a 300 or 380 engine in my Blaster but it turns out the primary gear ratios are worse than the 250, which is still very high. I am running 12/44 to get 65-70mph. Even at that, my transmission ratios are so close that first is tall to start away in mud or dicey situations.

The almost 50hp motocross engine is tuned for peak power. I cheated a bit, adding some to the pipe length to bring the power band lower. It still has less torque than a stock Blaster on initial off idle clutch release. This motor is about 6 lbs lighter than the Blaster engine, which helps to make up for the extra weight of the radiator and coolant.

It is hard to beat the stock Blaster motor. Good gear ratios, good design, cheap parts and a well stocked aftermarket. Unless you have the design and metalworking skills to make pipes and weld on chrome-moly, I'd stick with the Blaster and mod it up with a new head, tight squish, light port.

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banshee motor would be cool

This one I have trouble with. Most of the weight advantage a Blaster has over the Banshee is solely due to the heavy Banshee engine. A Banshee powered Blaster would be shorter and narrower, but then the first thing most guys do is put a +4 swinger and Banshee axle on their Blaster. What advantage would I have sticking a Banshee motor into a Blaster over just fixing up the Banshee?

What is a person trying to accomplish with their swap?
We all like horsepower but if comes with 50-150 lbs more weight or frame
shattering vibration or poor gear ratios it will not make a better ride.

So, how do you make this pipe fit? And will it be in tune?

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Until I bought my first Blaster a couple of weeks ago I had been putting together a CR250 3 wheeler conversion (among other projects). All the parts was coming together fine until I got to the pipe. I don't have the ability or knowledge to build a pipe and having one custom built is expensive, from what I've been told. If you can make your pipe, a swap wouldn't be a bad idea but if it's going to cost $500 to $700 for a pipe (like I was told) then the swap price get out of hand quick. If the pipe wasn't an issue I'd get a big air cooled 2 stroke, like a yz/wr 465-500cc. One of several things that made me settle on a Blaster is it's simple. Air cooled, no power valve and 2 stroke is about as simple as it gets (after dealing with hard to find 3 wheeler parts, the abundance of parts for these little quads was what sealed the deal for me). I'm new and don't have people names down yet but there is a guy here who has a Hanna retro Blaster that I love. If I was to the point that I wanted to build one without the Blaster engine, that would be what I would do.
 
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Pipes, pipes, pipes ... this, vibration and gearing are the bones opinionators love to pick over. Few have spent much time riding 250 Blasters ... My first pipe might not have been great, who knows? Of course it must be screwed up cuz I modded it myself :) Is a FMF screwed up cuz someone likes a dynopro. Peeps will argue bout pipes regardless. The YZ was so much faster than our 240 that we could care less whether the pipe was perfectly tuned to the motor. I doubt I'll ever run across another YZ blaster to compare it to and would the difference be the pipe, the porting, the carb, the gearing, the methanol, the rider ... I'm building a new pipe cuz it will be shinny, I'm not worried about it being fast ... I'm sure it will be fast enough! Not perfect but poor as compared to what. If you're concerned about not being able to overcome the challenges of building a hybrid ... don't do it. Making it work is what it's about cuz it won't be a better quad than it was as a Blaster
 
YZ Otis, My typing leaves something to be desired and in this case completely changed what I was trying to say. Edit complete and what I meant to type was "If you can make your pipe, a swap wouldn't be a bad idea but if it's going to cost $500 to $700 for a pipe (like I was told) then the swap price get out of hand quick". I'm sorry for the mistake. In my case the pipe was an obstacle that put the project on hold and I sold all my 3 wheelers and parts a week after I bought my first Blaster. I had just gotten tired of the search for and price of parts. I bought my first Blaster for $100 more than I had just paid for a set of use plastic for my 84 Tecate. If I had of stayed with it, I would have worked something out for a pipe but switching directions put an end to that project and 2 others. I didn't mean to discourage anyone from doing a swap, just offering some insight on a key factor that I hadn't accounted for until I was in too deep.
 
Is there a lot of fab work required to fit a YZ490? It was something I always wanted to do to one of mine.. but I had trouble locating pistons.
 
the 400, 465 490, ur going to have trouble finding pistons for them due their age and well they dont make them anymore. they can be fabricated, whoch people that have these swaps do. fabrication for this to fit yeah theres going to be a bit of it. the biggest thing for this motor is vibration so ur going to be reinforcing the frame, cutting and moving motor mounts, its a lot of work but in the end a neat build to do. paulie b would know more about it in depth because he dropped a yz400 in his. i was going to do a 465 for mine but i lost the engine on ebay and didnt find a decent running one after that.