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2006 CRF problems with Popping when I let go of throttle and bogging

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Posted by: T-Bone---------------------

I know this is probity a common thread but I have a new CRF 250 and it has a JD jetting kit in it but I still have a strange bog and the bike pops on the deceleration . I also have to have the throttle half open to start it in gear some time s. Anyone have there bikes dialed . I'm on the West Coast near Seattle


Posted by: whenfoxforks-ruled---------------------

Hello T-bone, I would check he valve clearances and then yank the carb, strip it and clean it. Stock jetting should work. What all have you done to it? How many hours? How many shim sizes has your adjustment moved? Leak jet and ap will cause the bog and pop, the mixture screw will effect it also. Proper installment of the o ring, washer and spring on the mixture screw will do this.


Posted by: Shaw520---------------------

Quote:
Originally Posted by whenfoxforks-ruled
Hello T-bone, I would check he valve clearances and then yank the carb, strip it and clean it. Stock jetting should work. What all have you done to it? How many hours? How many shim sizes has your adjustment moved? Leak jet and ap will cause the bog and pop, the mixture screw will effect it also. Proper installment of the o ring, washer and spring on the mixture screw will do this.

What he said
T-Bone,.. what you are describing could be a lean idle curcuit, ie: pilot jet


Posted by: Spokes574---------------------

Typically when you cut the throttle and hear popping its typically due to a lean circuit. Typically need to go to a larger Pilot jet.

Starting issues. Ussually due to valve clearances. But I had some that were not valve related. If the fuel screw is too lean it will lead to tough starting. I would try richening the fuel screw 3/4 turn - Fuel screw could also be causing your bogging/hesitaging if its tool lean. Based on your description is sounds like you need a larger Pilot Jet and you need to richen your fuel screw to about 3/4 of a turn more (CC to richen)

Try that!
Spokes574


Posted by: truespode---------------------

Is this a new symptom or has this been going on for awhile?

If it is new then has the weather gotten considerably colder since when it was running fine?

Ivan


Posted by: whenfoxforks-ruled---------------------

Can you imagine all these jetting issues disappearing after efi?


Posted by: truespode---------------------

Quote:
Originally Posted by whenfoxforks-ruled
Can you imagine all these jetting issues disappearing after efi?


They won't. You will just have to change your mapping with a computer instead of jetting with brass.

Ivan


Posted by: Rotorranch---------------------

Quote:
Originally Posted by truespode
They won't. You will just have to change your mapping with a computer instead of jetting with brass.

Ivan


Yep, instead of a wrench you'll use a laptop.

Rotor


Posted by: whenfoxforks-ruled---------------------

With a couple of add ons it can adjust itself!


Posted by: 450X---------------------

i have an 05 crf450 and it bogged terribly from the factory i have done some things to help this the one that helped the most was the Boyesen quickshot accelerator pump cover, pretty easy to install and lost 80% of the bogging, great investment at about $80.


Posted by: mox69---------------------

Quote:
Originally Posted by truespode
They won't. You will just have to change your mapping with a computer instead of jetting with brass.

Ivan



This is somewhat misleading. If you want more performance you can remap the ECU (just like in a car, they call it "chipping the car"). But you will never have to "re-jet" the fuel injection for weather / temperature / altitude / etc.

Just like you can take a Polaris Sportsman 700 from sea-level to 5000 feet without changing anything, you will be able to do that with your bike.


Basically "tweaking" the EFI will be possible, but mandatory tweaks won't be necessary (assuming Suzuki does their job , lol).


Posted by: Rotorranch---------------------

Quote:
Originally Posted by mox69
This is somewhat misleading. If you want more performance you can remap the ECU (just like in a car, they call it "chipping the car"). But you will never have to "re-jet" the fuel injection for weather / temperature / altitude / etc.

Just like you can take a Polaris Sportsman 700 from sea-level to 5000 feet without changing anything, you will be able to do that with your bike.


Basically "tweaking" the EFI will be possible, but mandatory tweaks won't be necessary (assuming Suzuki does their job , lol).


That depends on how "smart" the system is. The smarter the system, the more complicated it becomes. Bigger ECM's, O2 sensors, air flow sensors, knock sensors, temp sensors, etc, all become necessary as the system becomes smarter. With that, comes added weight, and reliability issues. More stuff to go wrong.

With the added electrical components and higher current draw, comes the need for bigger, heavier duty charging systems, adding more weight. Maybe even batteries.

For now, I'll stick to my carbs.

Rotor


Posted by: T-Bone---------------------

Hi guys , The bike is new and I only have 4 hours on it. I was looking at the quikshot and thought about buying it but I see there is another brand that is cheaper ... is it as good ?????????


Posted by: Rouse5369---------------------

Boyseen quick shot fixed our bike also, 2006 crf250, after little tweaking of jets, bike runs great, about like the other guy said 80 to 90 percent gone, i didnt notice it at all running vp race gas ultimate 4. but who can afford to keep running that stuff, we just put premium gas and some octane boost from time to time. i dont know about the cheaper brand, but i dont hink id be the guinne pig, when you get that cover, youll be like $80 for this???? but it works


Posted by: whenfoxforks-ruled---------------------

Try a 70 or 75 leak jet. Get jd jetting's o-ring mod for the ap adjuster. Set the ap squirt so it just misses the slide.


Posted by: 450X---------------------

i dont know much about the other brands, usually its a (get what you pay for) type of deal, its hard to fork over $80 for something the size of a silver dollar , but im telling you its worth it.


Posted by: Jeff Gilbert---------------------

I've been real lucky so far since i went to a four stroke. My 250sxf had a bog from he double L when I 1st got it so I called my dealer to see if the had the quick shot everyone else was putting on their bikes. He just told me to bring it down & he would fix her up. I didn't see what they did cause I was busy talking when they did it but what ever they did, they pulled the tank off and used a peice of safety wire to wire something up. It's been over a year and I've never had a bog since. When I get a chance I plan on taking things apart to see what it was they wired. What ever it was, they told me they do it to all their race bikes and it works. I'll advise when I find out what it is.


Posted by: whenfoxforks-ruled---------------------

They wired the ap adjuster. JD sells 2 different size o rings that do the same thing, and if you try them you can tell the difference from the 2 different strength o rings. Some believe wiring it up solid makes the ap rod bottom out the diaphragm. That is the why they grind off one side of the diagram, or buy one already modded. 06 and older the ap adjuster floats. In the motorsport parts book I have seen a modded adjuster, modeled after the newer carbs. On that wire mod, my son claims he feels it bottom out(in the throttle) and I do not? We put a modded diaphragm because it figured. Our 250f was not as finicky as the 450. Nothing like coming off throttle and looking at a jump coming, and getting a hesitation! The o rings wear out and I have switched to iddy biddy plastic zip ties, red ones.


Posted by: hot125mod---------------------

what exactly do you do with the wire? more than just tie it to the ap. Is it so the ap squirts earlier or longer? there has been no clearence issues of anykind or hanging up?


Posted by: _JOE_---------------------

The fuel in the little bowl under the diaphragm creates resistance as you turn the throttle and force it up through the squirter. Tying them together forces the fuel out quicker. You can experiment with leak jets to tune for the best response. They are difficult to access though , as you need to remove the float bowl for access. The timing is probly the most impportant thing though. That fuel needs to get into the intake ASAP, so you need to trunt the adjuster screw until it just clears the slide. The idea is that the AP provides fuel while the engine builds the vacuum to pull fuel in through the carb. The diaphragm has a rivet holding the rubber to the metal center, this will bottom out if you don't shave it. The amount of travel until it bottoms dictates the volume of fuel pushed through. The bog people feel is the AP squirt failing to provide the right amount of fuel at the right time. I run the stock AP cover and have zero bog. JD needles are great for response and midrange performance.


Posted by: Matt90GT---------------------

dont waste your money on the aftermarket covers. Only one I would consider is the R&D one since it has an adjustable leak jet.

You need to change the leak jet, modify the AP circuit like stated above. Then go to a 45 pilot and stock main, adjust the needle and fuel screw. I assume you have installed an aftermarket fuel screw so you can tune it easily already?!!!. From there either get the R&D bowl or start playing with different size leak jets.


Posted by: whenfoxforks-ruled---------------------

It did take a few minutes to find, http://www.dirtrider.net/forums3/sh...hlight=adjuster



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