Hard to start 2006 TRX450?

[motoz/HMF]

Our 2006 TRX450 was IMPOSSIBLE to start no matter what the outside temperature is. We would crank away for 30 seconds or so and no dice.

Our TRX STILL does stall out sometime and then just cranks and cranks and cranks till the battery is dead, then we pull start it and it runs fine.
We cannot figure it out, must be an ignition or black box thing.

Hopefully, you already have the HMF adjustable needle, pilot and main jet that I suggest and have modded your airbox lid or removed it.

You will need to change and adjust a few things to get your 2006 TRX to make it start easier.

1) You will need to remove the carb and adjust the accelerator pump so that it squirts just after the slide opens. The AP adjuster is under the black cover on the side of the carb(a special tool will need to be made to turn the tamperproof "D" shaped adjuster, it is locktighted in place so do not try to pry it with a screwdriver or anything else).
2) You will need to change the leak jet from the #70 to a #50 or #40 (available from Yamaha).
3) Swap out the stock "D" shaped fuel screw for a SCOTTS "T" handle.
4) I added a Boyesen Quickshot AP bowl.
5) While I had the carb off I bypassed the micro switch at the throttle shft.

THERE now you have NO excuse not to get the holeshot !!!


Your TRX should now start better.

[Tripyn]

Thks for the info John,

I agree about the boyesen, I pulled it this weekend and had the tow line out more then once ( really sucked after smok'n his YFZ all day that he had to pull start me.) One thing, when you say bypass the micro switch, do you mean disconnecting it at the thumb throttle and sodering them together at the carb? I have read that somewhere else and they say it helps.
I can't wait to make this starting problem go away, makes it hard to do wheelies!

[motoz/HMF]

REMEMBER you are removing a SAFETY SWITCH do so at your own risk!!!.

Bypass both micro switchs by eliminating them and connecting the wires together.

[motoz/HMF]

This is the leak jet located in the float bowl.

[motoz/HMF]

This is the A/P adjuster (the black side cover on the carb has been removed)

[motoz/HMF]

Close up of the A/P adjuster.

Use a dremel and a narrow sanding disc and make a slot across the adjuster and outer collar, that way you can just use a screw driver to adjust the A/P

CAUTION: IF you are using a grinding wheel beware of sparks, the gasoline in the carburetor

[motoz/HMF]

Add the Boyesen Quickshot and Scotts "T" handle fuel screw to finish the mods.

[motoz/HMF]

Bypass this micro switch to prevent a future DNF.

NOTE: you are bypassing a safety switch, do so on your own and know that you are disabling a safety switch.

[motoz/HMF]

Now how easy is it going to be adjusting that fuel screw.

[motoz/HMF]

The next valve chaeck you do make sure the decompression is set a tad loose, reports are that too tight causes hard starting.

[redrash]

I am curious what the micro switches do? What is disconnecting them supposed to do for me?
I have a '06 450R and have just installed the sport series system. It sounds sweet, and fit very well!
Thanks

[brandon837]

what is the safty switch for and why did you bypass it

[motoz/HMF]

what is the safty switch for and why did you bypass it

The switches are for if the throttle sticks wide open the thrmb versus the slide would be different and the machine will cut out.

Why bypass it...because switches can go bad and the cost of racing these days it would be sad if a 20 cent switch cost you hundreds to race. IF you would rather play it safe leave it alone. No reported switch failures so far.

[brandon837]

thanks one more question the d shap screw on the Accelerator pump the same size as the air screw on the bottom of the carb or is it bigger

[motoz/HMF]

thanks one more question the d shap screw on the Accelerator pump the same size as the air screw on the bottom of the carb or is it bigger

The AP adjuster is different size than the fuel screw.
Replace the fuel screw with a Scotts "T" handle, we sell them.
The AP just take a small dremel grinding wheel and cut a (-) slot in it then simply adjust it with a flat blade screwdriver.

BE CAREFUL GRINDING, SPARKS CAUSE FIRE, DRAIN THE CARB COMPLETELY FIRST AND TAKE THE CARB OFF THE MMACHINE.

[Rickycillo_TRX450er]

Bypass this micro switch to prevent a future DNF.

NOTE: you are bypassing a safety switch, do so on your own and know that you are disabling a safety switch.

DNF stands for?

[Mike/HMF]

DNF stands for "Did Not Finish"