Yfz450 ziptie mod

The Bog: it happens when you stab the throttle from idle and the motor lays over and will die or almost dies. It can happen in gear or when you are in neutral and usually people will rev the motor up some to get past it.

The Cause: The reason the bog happens is there is a delay in the accelerator pump squirting fuel into the motor when the throttle is snapped open and causes it to go lean and starve for fuel. Now, the reason for the delay is because when they manufactured the carb, they put a weak spring on the accelerator pump arm, so when you stab the throttle, the accelerator pump cam arm and adjuster moves away from the accelerator pump arm and when the reservoir for the accelerator pump is full of gas it can take up to a full second for the arm to move due to the pressure on it and there for will starve the motor for fuel. As soon as the reservoir is empty, they move in unison they way they were designed to do.

The Fix: To cure this, we need to make the arms move together. The way to do this is to zip tie or use a rubber o-ring to hold them together. I prefer to use a zip tie because there is no stretch in it; you choose which way you want to go.

The Instructions:
Remove the 2 allen screws that hold on the cover to throttle and accelerator pump. It is on the right side of the bike and the throttle cable goes into it.
At this point you will be able to see the arms as well as the throttle wheel. If you can not get in there to do the zip tie or o-ring, then follow the proper procedure to remove the carb from the bike, this is optional because with a little bit of patience you can do this in the bike.
Once the cover is off, take your zip tie and start it so that you have a loop and a handle to help maneuver it over the arms, keep the loop big enough to go over the adjustment screw. Try to keep the head of the zip tie towards the bottom as you don't want to have it rub or interfere with the throttle. Get it pulled down tight and cut the excess off.
Test the throttle or if you have removed the carb, reinstall the carb and hook up the throttle cable and test
Reinstall the cover.
Fire the bike up and test while in neutral and there should be no off idle bog.
Test ride the bike, if there is still a low end bog, you need to look at your jets.
Note: I borrowed this picture from another forum and in it they used the o-ring, but it still gives you an idea of how to do this what everything looks like. Again you can use either a zip tie or an o-ring.

Category:

Sports

Tags:

• Yfz450
• Ziptie
• Mod

[spazmoso]

@autolover3 i see this comment is a year old but whomever is thinkin k and n filter watch out if its not on perfect and too tight or loose it leaks bad shit into the cylinder,the foam ones are fine and for what u pay u can buy 4 or 5 for the price of the afore mentioned filter.also pc racing seals a neoprene gasket that eliminates lithium soap grease(wich no one uses but should)

[autolover3]

@Tooextrememx i installed a boyeson q3 with adj leak jet. also went through whole carb and cleaned it. its doing alot better

[Tooextrememx]

@autolover3 change your leak jet to a #35

[autolover3]

hey i have a 07 yfz. i did the ziptie with a thick oring and it still has a bad bog. it even does it while riding in mid rpms and i stab the throttle. i have a jd fuel screw. 168 main. 35 leak jet. 48 pilot. jd "blue" needle on 3rd clip if i remember correct. motoworks full exhaust. stock intake and filter. im gonna get a k&n this week cause foam one ripped. my mid to top end is awesome but still tryin to get bog taken care of. please help. first race is comin up soon