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So i just picked up my sons 08 raptor from the mechanic.I put a lexx slip on exhaust on so i wanted to jet the quad.I purchased a gytr jet kit and gave him this when i left the machine.I now have a k& n filter on the machine. I asked hows it running and he says ok but it bogs in first? Need to take off the k&n which he says lets in to much air.Advised me to put a twin air filter on and said it should fix the bog?Any thoughts.
 

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that mechanic is a moron. a little too much air does not make the engine bog. too much air makes the motor run lean which would do the opposite of bog, it would take away your top end power in all of the gears. The only way the engine would bog from too much air is if it is not getting any fuel, like if the jets were clogged or something.

You can leave the K&N on there, although it is not a recommended filter since it does allow lots of tiny dust particles into the motor.
bogging engine would be caused by running too rich.
did you take off the airbox lid? believe it or not, taking that lid off actually allows less air into the motor which will cause it to bog.
If the air lid is still on there, then it must be jetted a bit too rich. There are some things you can do to lean up the mixture so you won't get the bog, or you can have it rejetted again with a leaner mixture, or adjust the needle.
 

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So i just picked up my sons 08 raptor from the mechanic.I put a lexx slip on exhaust on so i wanted to jet the quad.I purchased a gytr jet kit and gave him this when i left the machine.I now have a k& n filter on the machine. I asked hows it running and he says ok but it bogs in first? Need to take off the k&n which he says lets in to much air.Advised me to put a twin air filter on and said it should fix the bog?Any thoughts.
Incorrect fuel air ratio can cause a bog from idle, rich or lean, both have different characteristics, but both will feel as a bog...........
 

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Discussion Starter #4
Lid is on.should i take ot off?He said he went by what gytr instructions said.135?Dont have paper in front of me.So getting a twin air filter wont help?Should i just take it somewere else?He charged me 100.00 to put jets in.This is getting costly.
 

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More than likely, you are probably lean. Most bogs are from being lean. When ya crack the throttle, air moves faster than fuel, so if ya dont have enough fuel you will have that bog. Thats why some of the high end carbs have accelerator pumps, for fuel can keep up with airflow. Was the cap that covers the airscrew removed, and the air screw turned out some? That will effect off idle performance. You might wanna read this about somebodys experience with the GYTR jet kit http://blogs.atvrideronline.com/633...p-quadcross-limited-mod-race-class/index.html
 

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Lid is on.should i take ot off?He said he went by what gytr instructions said.135?Dont have paper in front of me.So getting a twin air filter wont help?Should i just take it somewere else?He charged me 100.00 to put jets in.This is getting costly.

From my experience, it will run stronger with the lid off. I removed the screen, have a k&n filter with outerwears, a full CT racing exhaust on my sons 250. I jetted it by using CT's instructions, their needle and a 165 main jet with no lid. It runs really good. I put the lid on just to compare, and it spit out black smoke, and felt lazy. Your gonna have to jet richer without the lid. Having the lid off is going to let in much more air in than those 2 little holes on the lid. Make sure ya check out the link in my previous post, sounds like your having the same problem
 

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never once have I ever had a bog from running lean, and there was a time where my plug was completely white, no bogging..
I've had nothing but bad luck with removing my air lid. everytime I do, the engine can't rev up past like 5k rpms and then it floods. I think that the way the snorkel on the lid is designed, it pulls in a lot of air, more than it can without the lid on..
check your spark plug to see what color it is

white/gray = lean
beige/brown = perfect
black = rich
 

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Did he only switch the main jet (133 to 135)? If he didn't put in the pilot (2 turns out) and needle (2nd clip) that could be your problem.

I am not sure what everyone's problem is with the GYT-R jet kit. I have the GYT-R filter, head pipe, exhaust, 10.5:1 piston and stage II CAM. I am still running the GYT-R kit with the 27.5 pilot, needle clipped per Yamaha's instuctions and 140 main jet. I am not sure why people have to run 150 and 160 jets.
 
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