that happened to my brother on his blaster. the wiring going to the throttle was all crappy, so it was always stuck. nice that u found the problem.

 

Wow ! Talk about lucky..... haven`t been to the forums in forever, but needed some advice on an electrical issue with a 450 .... and found this one on the first page.

O.K. .... IT WON`T FIRE ! Replaced the 04 stator (which ohmed bad) with an `05 model. Trimmed the wiring harness down to bare essentials (Drag-only YFZ450ish). All other components are KNOWN GOOD. Except the CDI (am working on a known good one to try, should have tomarrow) If the CDI checks out good, what is the chance I screwed up the Tors/Tps wiring? The 4 wires coming out of the Cdi marked blue - blue/black - yellow - yellow/black (from memory) ? Should they be tied to each other? <-- then grounded ... or just grounded, or just sent to their rooms for an hour without dinner ??? Learn me. :-)
And how about any other reasons the coil won`t fire on this bike...... but WILL on a stocker? Gap and all the other "first to check" items have been combed through....... many many times.

Help ... and thank you.

 

miniquadmom, Glad to hear you figured it out.
Forcefed, Looks to me, the throttle and carb switches are normally open. So grounding them could cause a no spark. Id just disconnect the y/b wire, which goes to both switches, and leave it hang. Then with out using any throttle, turn it over and check for spark.

 

hey everyone, got a new member here! i have an 08 yfz 450es an im having a fire problem, now im getting fire to where the wires plug into my primary coil but nothing down to my secondary, ive replaced the coil already an same thing still nothing coming down to my plug, i was talking to a guy from a local dealer an he said it might have something to do with my idle turned up to high which cuts out my coil somehow so i tried that an was still getting nothing, when i put the test light into the plug that comes from the wire harness i was getting fire from both wires, one side wasnt as much as the other but that dont sound right to me? if anyone has any ideas of what my problem could be ide love to hear from ya thanls!

 

I'd like a diagram of the wiring for the 05 yfz 450

 

Jaycook. If you want to post a thread, there is a red, rectangular button at the bottom of the page that says "New Thread" click that and make your own post

 

I have a 2008 yfz 450, I hope you can help me I run out of ideas, the motor does not turn slow, the spark has a current and the stator is new the current is fine, change the timing chain and put on a new one and piston rings Again it was put in time as it should and does not start the engine slow, what can it be?

 

Hey I am not sure if you are aware but Mudline Motorsports offers a free tech support line. I was having issues with my 2006 YFZ450 not starting last year and reached out to them, they walked me through what needed to be done and it was extremely helpful. Here is a link to their website!

https://mudlinemotorsports.com/

 

LIsten you yamaha quad guys. I am 56 been racing profesional and working on bikes quads everything my whole life. If your one of those sissies that rides a yamaha quad, dont be mad, quads are for sissies that cant ride two wheels, lol, Rip that stupid yamaha ground wire and that stupid bullet connector off your quad, solder in a new wire straight to the battery. Then run another groud from the clutch holder to the frame, then I like to run one to the subframs and then a muust up by the cdi or computer box. So when something stupid happens to one of your grounds you have backups and you will be suprised how much brighter your lights and how much more responsive your fuel injected motors run. I dont know what is going on with yamah. I have fixed a few during covid. usually sell tools for a living, but I rock has a tech. Yamaha needs to get there head out of there asses and fix this wiring, wireharness cheap shitty connector problem that is on all there ****. R1s, quads, 450rs the whole deal. I made my own harness out of real wire and delphi connectors no more issues. Its bullshit been going on for over ten years. Id call Keith Mcarty but he is an idiot. Have a nice day. Yes my name Flyn Ryan Menke. this will be my only sissy quad post forever!