YamaSaki YFSex-250 build

So further updates...

Loving the swap now. Its bad ass! GOBBS of power and torque! Only problem im having with it now is that it is chewing up chains like they are going out of style!

I swapped the front back to the 14t and kept the 49 on the rear and seems to have helped some. I still havent gotten around to making a spring loaded chain tensioner yet but the 14T up front has taken up some of the slack. It ultimately turns out that I have the motor just slightly higher than the pivot of the swinger and that is ultimately the problem. I am working on a solution to bring the back of the motor down about 1/2" or so and that should line it up pretty good but that requires some major surgery as the exhaust and lower frame rails will need to be modified to suit so that is for another time.

Heading up to do some proper trails today so I should have a real ride report and video this evening or tomorrow.

- Justin
 
dang am i glad i found this post. that is one sick blaster. i have a 2004 yamaha blaster that i got last year and since ive had it i had to rebuild the top end once and put 2 cranks in it! after the last crank locked up i said f**k this and startd looking for another motor. at first i thought i was gonna have to use my 1974 kawasaki 2 stroke dirtbike motor but then last week i finally found something worth getting. i got a 1991 kawasaki el250e elimintor motor for 60$ (which is the same motor as a ninja) and ordered me a ninja cdi box for 32$ of ebay (which im still waiting for it to come in the mail). i have the same problem you started out with. where am i gonna put the raditor. i like where you put yours but i do alot of trail and woods riding so i think im gonna try to do something different. as far as the wiring harness i would really like to know what all you did to yours cuz i need help elimiating un needed stuff on mine. any help would be greatly appericated!!
 
Yeah, radiator placement and selection for me turned out to be laziness really. I had the ninja rad and didn't feel like trying to figure something else out... and I wanted fans - I live in the desert now so heat is an issue.

as far as the wiring harness i would really like to know what all you did to yours cuz i need help elimiating un needed stuff on mine. any help would be greatly appericated!!

Well for electrical, I had to rebuild the ENTIRE harness from scratch. Its actually not all that bad and mine is a bit complex due to the all the extra wiring I did for the fans, HID headlights, LED tail lights. I basically got all of the components that were going on the bike (CDI, Switches, keyed ignition, coils, ect) and sat down with a wiring diagram so I knew what wires on the components were what, and just went to town.

Also, on mine, i designed the electrical system so that the charging circuit would be completely isolated and non-dependent on the main system. This one done for the fact that I tend to venture into a lot of really remote area and if the charging system failed on me, I would still be able to run off battery power for a while to get back. I have a little LED volt meter that shows me the condition of the charging circuit so i can clearly see if it fails. I think it was a walmart "on clearance" thing with 3 LEDs. When running, all 3 lights light up. If i disconnect the charge circuit, it drops to 2 or 1 light so its obvious.

12v feeds from the battery to the ignition, ignition to solenoid, solenoid to starter and cdi/coils, and lets not forget the solenoid to starter button and back, and also out of the keyed ignition to the lights and fan, and depending on if you want the fan to stay running if you hit the kill switch or now is another story.

Its certainly not for the faint of heart. I just centralized my wire bundle and left all my separate leads long so when I fit it to the bike, I trimmed all the wiring to fit. I also used much of the stock Kawasaki harness to cut plugs off and re-purpose them for use on this harness to I could strip it apart, or you could go to radio shack and buy plastic plugs in all kinds of configs but use lot of dielectric grease on them because they are not intended for outdoor use and thus not water tight. I don think I saved my new wiring diagram because im sure it changed when it came down to actually trying everything, but I will look for sure.

If you have a basic understanding of electrical circuits, you will be able to frustratingly work through it. If not, I suggest retaining ALL original wiring and don't muck with it.

Good luck on the project. Your gonna need it. I sure did. I fought that damn thing for 3 weeks until i found out about the stupid resister they hide in the OEM key switch for the Kawi.

- Justin
 
and for what its worth, normal trails and anything but sand, my little yamasaki will hang with my buddies LTZ-450 unless we are on some real long and steep uphills (hill climbs) - then he pulls on me.

- Justin