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.