bigborebanshee

just a couple from last weekends shakedown run.Only casualty was the lower chain roller.Must not have loctited it because the bolt spun right out.

Not too bad,front end is light.As far as power goes,I think a stock trx250r would get stomped by the yz250,the yz is a dirt bike spec engine,the trx250r were detuned from the factory for the quads.

found a graphics kit for the 250.looked for a retro 80's ,but all i could find was a nacs racing.looks good and can pass for trx250r,except its yamaha powered.

No chain problems on either conversion.Im a machinist by trade so I fabbed some nice tools to get everything lined up straight. Just finished the yfz 250 hybrid.Would love to line it up with a 80's trx250r. The lrd 250b pipe works well on the yamadog.

i am currently building a yfz hybrid witha 86' yz 250 in it.the case dimensions were similar,so I found another yfz frame and started a ground up build.When i complete the build,i will post some pics here. http://forums.everything2stroke.com/showthread.php?t=48319

It already has 2 of those rubber isolaters on the cylinder.the vibes are not bad at all,they are only noticable in the lower gears at peak rpm.there is no mistaking this engine for a blaster,sight or sound.If you know bigbore 2strokes, the sound is unmistakable. I spent 400 on the rolling chassis minus the subframe. I used a yfz mx racer friend to source most of what i needed to finish the chassis.In total i have about $2000 into this project minus the "sweat equity" I will probably NEVER buy another factory quad again.i had too much fun building this one and after 2 hard rides,it has shown to be reliable on the trail.It helped to have access to a full machine shop with welding capabilities. Everyone kept saying it would vibrate itself to death.But i did enough research and attempted to counter every issue i would face with this build.I think the biggest problem people face with conversions is the rear engine mount.The rear mount MUST use the swingarm bolt. i see a lot of guys fabbing up a there own rear engine mounting brackets. this is where most of the vibration is harnessed. You might be able to get away with it on a banshee engine,but on a non counterbalanced single,it won't happen. it will eventually break the mounts.

Took the 465 down to Wayne national forest. Runs like an animal. you can literally lug this thing around in 3rd,power is very tractable. I spent 4hrs on this thing and it passed all of its tests with flying colors..Even at slower trail speeds,the cylinder temps stayed withing the 200-220 range. Not as powerful as the 80 hp banshee I had,but It easily put my friends 686 rappy away. Not to mention the flickability the lightweight combination provides.

Well,its done,the yfz465 is completed and runs like champ. its hard to believe the trx250r pipe worked so well..this is definitely comparable to my old cr500. Jetting ended up at 158 main and 55 pilot on the 38pj. The vibrations dissipated a lot when i tightened down the swingarm bolt. This thing is an animal, heading to wellsville 2 morrow. Will post up some videos

Well, i got a chance to shakedown the hybrid today and she has some gremlins in her. First i started the jetting on the 38pj at 180 main and a ddj needle.it ran terribly,i switched over to CGL and it revved a little better but would not rev out.So i started dropping the main,first to 170 which showed great improvement,then to a 160 and the wheels began to come off the pavement,It still needs work on the main and maybe needle,but it is a lot closer than it was. I adjusted the clutch to where It had good free play and used Honda HP red in the transmission, but for some reason,when I let out the clutch,it just stalls.I kept taking the slack out of the clutch and i was able to get it to disengage enough that it lurched and started to roll,not sure what the hell is going on with that.i could not adjust it enough to completely get rid of the lurch.i have a pancake bearing from a banshee .I am going to see what i can do about making it work.Im also going to put a stock shift star back in.I modded a stock one to combat a notchy shifter,but maybe i removed too much material? This thing vibrates like nothing i have ever experienced .its not bad on the foot pegs or seat,but the bars are horrible...Im going to pull the clutch cover this weekend,check the plug and maybe try to get it dialed in better.Once i get the clutch issue resolved i will post a video of this beast.

I came across a 250R fatty pipe I had from a part out from long ago.i decided that i could not wait any longer to see if this beast will run.Since the 250r headpipe is separate from the expansion chamber,I decided to hack it up to suit my needs.After some tacking and welding,I mounted the pipe. A few kicks is all it took to bring it to life.Its already dark here,so i did not get a chance to ride it but it has good throttle response and the BIG BORE RING! Can't wait till tomorrow!Not sure how it will run with the 250r pipe,but it feels good to know its almost there.

A good example would be Suzuki and kawasakis first venture into fuel injection..Guys were pulling off the EFI because it was impossible to get them to make good hp. Only after the aftermarket started producing ECMs did they figure out how to make them run hard and make big hp. Considering the money and R&D they put into it,I am betting the cost to mass produce a kit that would actually work and run right would out weigh the return. Considering there are hardly an 2 stroke models left,it would be the equivalent in investing in vacuum tubes and transistors

680 bucks for 34PJ's?...a set can be purchased from CPW new for about 250 with cable..The have been discontinued by Kehin and are literally gving them away and you could ebay most of the other stuff for less than half.

I have to agree with the poor installation or improper torque, but I also agree with the helical gears are compounding the issue. If the torque was correct on the center mains,the crank should have never walked over and slapped the bearing.

I did not have T-5, I had DMC aliens which are not much different than T-5's on a set of vitos 421 cylinders.With 30mm carbs and DMC pipes,it made 55hp I bolted on a set of CPI inframes and 34.5 PJ carbs with a full airbox and K&N powerlid.The engine made just under 80hp and probably would have made more with shearers considering the 200 degree exh port duration .Some pipes just won't work on the big bore stroker engines.

That is why I had to build this quad. The single 38PJ offers a plush throttle and the bigger clutch offers an effortless pull even with HD springs installed. I like how the Yfz rides and handles the trail.The banshee felt HEAVY and rigid,but not this thing, it is going to fly.. How hard do ya think it will be not to wheelie when taking off.

Looks good!..I had the same issue with with a set of FMF pipes I got that did not have sparkys..I called Pro Circuit and told them i bought some 296 silencers and they did not have decals on them,they sent me 2 and i slapped them on the FMF silencers. Had trail cops look at them,but they never investigated past the sticker.

I have to wait until the pipe is built.If you look at the pic from the rear.There is not much room for the inframe pipe to snake through on the right side of the shock.I can't use the stock rezzy location from the factory yet .So i used what I had,The battery hold down bracket lined up with the frame holes and i was able to mount it up there without any hacking. If you notice,that is a banshee rezzy. There is plenty of room up front for the pipe,but not much where it goes through the frame.Until the pipe is routed,that is safest place for it. Cam.I just wanted to get the BS stuff done before the winter comes.I don't mind spending the next 5 months dressing it up if all the hard work is already done.That kind of stuff needs time.

I got a little further along with the project,I still need to route the electrical,install the chain,modify the cylinder head stay and get an angled pod filter instead of the straight one. Minus the odds/ends and exhaust pipe,it is nearly complete. Im looking to get a set of 20" kt355 or Ohtsu for the rear.This thing is amazingly lightweight,I cannot wait to get it on the trails.

Look at that engine in the before pics.The rest of the bike looked 10 times worse.It was a farm beater and started life as an IT465. I added the YZ cylinder and it has the IT wide ratio transmission.If it was a complete YZ to begin with,I would have probably just restored it,but the "it" was like the Malibu.They could run like Chevelles but they were not worth diddly squat $

I had this yfz rolling chassis that i never did anything with, Since I had some time and no quad,I started this project.I had access to a yz465 and after some dimensions were taken.The process began. With some machining to the engine case and swingarm.I was able to get perfect alignment for the sprocket and good relation to the swingarm bolt.I Used some aluminum 400 ex mounts up front to help with vibration and fabbed up a bottom mount that utilizes a banshee style engine isolater. I was able to modify the factory 450 head mount,so this engine has 4 solid mounting points.With the slightest tweaking of the factory 465 kickstarter ,it just clears the frame.Sent the frame out for PC black. I had to use a 89-90 yz250 angled intake for the carb to clear the shock.Amazingly the mounting holes were the same.I opted for a 38 PJ over the factory mikuni roundslide and added an angled pod filter.I wanted to use the 39 pwk but the wall thickness is too thin on the intake bell to machine it down a bit so it fits the yz250 boot. I tore the engine down to the cases.Replaced the crank,clutch shaft and main shaft bearings.I modded the shift star for smoother shifts and replaced all the seals.A new wiseco 86mm piston was installed along with some new reeds. I had to machine some material from the head to get the squish right.Even though the cylinder was ported,it looks like the squish was never checked or the head was replaced at one time.The squish before machining was .085,now it checks .055. I had to swap the head and tail lights for a 6V system.A standard single pole auto parts store lamp socket locked right into the existing hole,so a little work with some solder I managed to convert the lamp sockets to accept 6v 23.5 watt lamps along with 6v 5 watt tail lamp.I utilized a stock banshee lamp/kill switch so it appears to be factory.Tested the whole system with a 6V battery and everything works flawlessly and are bright enough for night riding. These 465s were not huge on HP but made great torque,not to mention they can take a serious beating for an air cooled engine . The weight savings that I have by ditching the yfz engine,radiator,fan,electronics,airbox,oil tank,hoses and lines,battery will put the weight under 300lbs. Im picking up the frame wed and will try to get it slammed together and get some pics with the plastics mounted,then i will tear it down the the bare minimum that is required to have the pipe built.I have corresponded with Gary at Sniper and as soon as its crated up,im sending it his way. Its not a banshee but its a 2 smoker yami

I decided to do the pipe right.Since I was able to put this build together for a very cheap price,i will invest the $$$ into a good pipe that is built for this engine.I have already contacted Gary at SRP and he said he can build one.just waiting to get the frame back and I will be sending it that way

I just want a pipe that is tailored to low/ midrange. Its going to be a trail quad and considering the power these things put down,I don't need to max out the HP. I have pics of the build here,but when I get the frame back from the powdercoater,i will post pics of the full build in the images section http://forums.everything2stroke.com/showthread.php?t=47164

I found it was a little more expensive to buy direct from Works,but i was able to get a shock tailored exactly to my specs.I did not mind paying more,since the vendors I contacted told me they had to special order from Works anyways.