Blaster motor swap - YZFS250f!

[fasterblaster870]

and engine is only as good as the person that maintains it.... but you are partially rite. to run a blaster in the 50 hp range things need to be changed. you have to start lookin into a gusseted frame/strong sprockets/stronger clutchbasket and better plates ask for internal engine parts a 2mm stroker is goin to be reliable. very reliable. add a long rod to it and i bet it will be more reliable than stock. i think a 2mm stroker with a long rod and mx porting is the best thing a person could get for mx racing. and you wouldn't like a 4 stroke..... trust me lol. you'd be kickin urself. you loose the feelin of a 2 stroke.... and rite now i know a guy that drag races a blaster with a 265 kit and a 4mm stroker puttin out 60 hp.....it has a full on drag port. he had it at sand fest and its still runnin strong. even a machine as stressed as that doesn't need a rebuild ever race.

Originally Posted by none

Why wouldn't i like a 4 stroke? Thanks for the cool info, however I'm not really looking for more than 35 hp and so a stroker isn't really looking to be down my alley. Reliablity is key. Plus stroking the bore is straying a little too close to the limits of what the enigne was designed for and its just a matter of time before you have a complete melt down... 50 hp is roughly a 300% increase over stock, and i'm sure many of the engine components (and other parts) will be over stressed. A system will only function as good as its weakest part enables it too!

Thanks everyone for all the help!

[370banshee]

faster870 is right it's all about how takes care of it!!!!

[Blaster]

its pretty much like this if you maintain it like crap it will run like crap but if you maintain it good it will run forever (just about).

[86ltracer]

pretty much, it comes down to what you want. a YZ250F is fast, and revs out at about 13,500. if something revs that high, you can just about bank on the fact that it is mostly top end power. however, a 250cc 4 stroke is only capable of just so much more power. you can get way more power from a 240 blaster. plus, you dont have to worry about mounting a radiator. you might be able to get 40hp MAX out of the 4 stroke. for less than $1500 you can get 45 reliable hp.

[criminalpoet]

Well, if someone is telling you that their Blaster is putting out 60hp I would definitely be asking them to show you the dyno. I spent 5 years building one of the most evil Blasters you will ever see and when it was all said and done it still only pulled 47hp at the rear wheels. Which is still by all means freakish for a Blaster.

I spent a lot of time and money at the dyno trying everything out from different port jobs to different head designs to just about every make of aftermarket pipe combo out there. We tried different size and types of carbs, different head designs I mean everything you could imagine except for alky set ups or add NOS.

I ended up using a stock cylinder bored out to accept an L.A Sleeve 240 sleeve that we ported the hell out of. Im talking huge boost ports in the intake that we ported and linked directly into the cases. Riffled exhaust port,ported piston, decked cylinder, 3mm stroker with a long rod, milled head, base plate spacer, swirled squish on the head, removed the counter balancer, lightened the flywheel greatly, sent all of the bottom end components through cryogenics for hardening, polished every tooth on every gear, properly milled the cases to accept the stroker, added the base plate spacer, utilized a 1 Dir Racing G-3 reed valve (dyno showed the G-3 to out perform the V-force 2 and 3 and every other reed valve out there) used a 35mm Keihin AirStryker carb riffled and bored to a 37mm, used a CPI Big Bore pipe, ran a UNI pod filter, used an irridium plug gapped at .28, and ran nothing but TRICK 110 mixed with Amsoil Dominator at a 40:1 ration, advanced the timing 3 degrees, hell, I know theres more but its been 5 years since I dug into that bike..
Everything was set up right and nothing but Amsoil fluids were used for lube and the rings had to be changed every 35 gallons ran through the bike.

And like I say, when it was all said and done it ran 47hp at the rear wheels. You know what I learned during this project? LOL, that if its more big time power that you want its cheaper to buy a bigger bike hehhehheh. I put into the motor of that Blaster 80% of what I payed for my 1 Dir Racing built 250R. And my R only had 4 hours on it and has all the bells and whistles and then some. Was my Blaster fast, you bet your F-en azz it was! Hell, it would give me a hard on every time I cracked the throttle wide open lol. But would it beat my R? NO!

I pushed the limits of the Yamaha Blaster to the fullest w/out going alky or to a NOS set up, and what I found out is that it does have limits. I do desert racing/riding and no matter how much hp and torque I got out of it the Blaster just didnt have the gearing to keep up in mph with the bigger bikes. In tight windy technical stuff I killed just about everything I raced though. Hell, lots of weekends I walked away with a lot of Banshee owners money lol. Id drag race them and get killed about 10 x in a row. Then id act all pissed off and ask them if they wanted to run them in the arroyyos accross the street for a 100 bucks. They always say yea with their new found and well deserved confidence from beating me 10 times in a row in the drag race. Then when we lined up in those skiny, tight, windy sharp turning arroyos, they found out that all that top end power they had in those Banshees was worthless lol outside of a straight line. But thats a whole nother story.

Go to either a bigger bike or a bigger non-blaster motor.

[370banshee]

oh how totally wrong you are.... cp customs has a 62rwhp blaster on gas...

a 3mm crank on a blaster is not the biggest.. a 6mm stroekr crank is... and.. the ct240 big bore.or teh ultimate cylinder is a far beter chcoe then a resleeved stocker.. member only2strokes has a blaster ta rund 6.9 in 600ft.... that wil destroy your R... with no trouble at all

[BlueDiablo]

its 500ft......

[criminalpoet]

Originally Posted by 370banshee

oh how totally wrong you are.... cp customs has a 62rwhp blaster on gas...

a 3mm crank on a blaster is not the biggest.. a 6mm stroekr crank is... and.. the ct240 big bore.or teh ultimate cylinder is a far beter chcoe then a resleeved stocker.. member only2strokes has a blaster ta rund 6.9 in 600ft.... that wil destroy your R... with no trouble at all

LOL! Well, I am familiar with who CP Customs is, from when he first stepped on the internet. On the old Blaster HQ board there was a lot of hype on his work. One kid had his full on drag port job with an out of frame drag pipe and PJ 34mm carb and some other stuff too. Now before anyone had ever got a dyno on Craigs work he and his loyal customers were claiming 40+hp on his drag port job alone. Well this particular customer went to have his bike dynoed and it pulled a whopping 23hp! Thats fact, thats from an unbiased dyno, and thats the truth!

Said guy ended up going to the late Hollywood Dirt and pulling more power out Hollywood Dirts work. Now im not about to get into a debate here, but again, I would have to ask to see the dyno showing 60+hp at the rear wheels. As far as only2strokes blaster goes lol, I would put the title to my R up with 10,000 that says he will not win. And id even be willing to go best 2 out of 3 lol. A few years ago I offered Craig, the owner of CP Customs a 5,000 dollar race, his Blaster vs mine, and I even offered to pay for his trip 1 way out here. He diclined, thats all im going to say about that.

No Blaster on any kind of Blaster motor is going to whip a built R in a 600ft drag! PERIOD! By 500 ft I will have already reached top speed in 6th gear with a 14 tooth up front and a 38 on back! A Blaster does not have the gearing to even almost touch that breeze. But like I say, any time any place and I will put my money where my mouth is.

[BlueDiablo]

There is video of that Dyno. SKipzero is they guy you wanna talk to. And trust me...with a 6.9 in 500ft....your gonna have one hell of a time beating him.

[criminalpoet]

You know I used to do a lot of fighting on the internet over stuff like this, but its just not my thing anymore lol. I will do my racing in the real world! I have stated my offer and its good indefinitely! If CP Customs has a 62rwhp Blaster than to my knowledge that is the most powerful Blaster ever built lol. Better than anything Dennis Packard or anyone else has built, and should be in the books as a world record holder lol. Sorry but I havent read anything about it yet. But I do know a hand full of guys that have been building race bikes since before Craig learned how to write his name that still havent been able to build a Blaster that puts out 62rwhp on gas. And all of the guys that im talking about do in fact hold numerous records and are in fact in the books. Thats all I have to say about that!