This weekend I purchased big guns full race system for my 04 660 Raptor. Has anyone set up jetting with this system? I also installed the pro design air intake with foam filter. I was planning to run with the lid off. I have been told from Big gun to run 150 on the right and 155 on the left with 27.5 pilot jets. When I went to purchase the jets I was told to run 155 - 160. I then called another shop and they told me to run 165 - 170. Reading the past posts on this subject I get the same kinds of answers.

Does anyone have any advice for me? I mostly ride trails through the desert. (Arizona)

Also does anyone know of a site that shows the walk through on changing jets on a raptor?

Thanks again!

 

Ok I will try an offer a little help here. 1. I dont know the elevation for AZ so the numbers might not be correct. 2. My brother in law has a Big Gun slip on and he is jetted at 157.5/160 only reason being he didnt have time to get jets before our last trip so he had to use what he had. He is running KN with proflow and is running lid. I have a WB slip on and in warmer (60+degrees) weather I was jetted 155/160 with KN and proflow with lid. Right now (40-60 degrees) I am trying 160/165 with 25 pilots at either 2.5 or 2.75 turns out. My other buddy has full yoshi system and was running 165/170 with proflow and lid on. Now he has the KN powerlid which is basically like running without a lid and is trying there recommended jetting with is way staggered 165/185.

So with all that said I would say with not knowing your elevation I would try 160/165 or 165/170 to start off with. Our elevation in Michigan is like 300-1300 above I believe. The higher the elevation the less jet you will need. colder=leaner, warmer=richer. Everything is trial and error pretty much.

 

Thanks, I am going to start 165/170 with 27.5. 2 1/2 turns and see how that works, I will post results tomorrow.

 

Yeah that sounds like a good starting point. I dont know of any sites to help you jet but here. I dont know if this is exact or anything and I dont know what you know so I tried to walk you through everything. Read it all first before you do anything because I might have screwed some things up. Took to long to type and didnt feel like proof reading it. Im also not saying Im 100% correct with this but I think its right.

First and foremost I would say check your float levels before you jet your fourwheeler. Search floats on here there are some good explainations on how to do this. (clear tube method) very easy to check. If they are in spec move onto jetting. If they are out of spec you will have to follow the instructions given and do it after step 11. Well I guess either way move onto the next steps here...

1. Turn fuel off and start and let run until it stalls.
2. Remove front grill (2 allen cap screws) on top, then grill pops off.
3. Remove 2 bolts from under seat, 1 bolt from under grill, 2 bolts from top of each head light bracket, 2 screw nut combos on fender brace.
4. Remove 3 bolts from tank. Remove line from tank at petcock valve use pliers or what i do is stick a flat screwdriver into the gap and pry off the petcock doesnt require much pressure. Remove tank.
5. Remove airbox lid and crankcase breather hose from snorkle.
6. You can either unscrew the rubber protector from the frame or just fold it back. I usually fold it back and snag it on the airbox somehow so it stays out of the way.
7. Remove the 2 I believe they are vacuum lines from the top of the carbs and remove the hose connected to the black swivel in the center of the 2 carbs on airbox side.
8. Loosen all 4 clamps to the carb boots(I recommend T-handle allen wrenches for this almost a must in my opinion, reason later) make sure they are very loose(I loosen them to where they are about ready to fall out of the clamp). I usually grab both airbox to carb boots and pull them off then i stick a finger in each and pull them up out of the way and then pull the carbs out.
9. Now that the carbs are out keep them right side up until you can get something to drain the remaining gas out of the carbs. I usually grab a 20oz bottle and place that black swivel male fitting from the top center airbox side of carb into the bottle and turn the carbs over nearly all the remaining gas will pour out that fitting.
10. Ok gas is out now its time to take the bowls off. BE VERY CAREFUL WITH THESE SCREWS THEY STRIP EASILY. Remove the 4 screws from each bowl. Here is something to try and break them loose by loosening motion if they do not budge that way and start to strip the scews try and reverse the process and tighten them you will here and feel a snap then they come loose freely. The reason is I believe the metal corrodes together and tighten actually helps break that bond and doesnt strip the screws in the way to get them off.
11. Now go to the hardware store and replace those screws with bolts or cap screws(allen bolts) I dont know the size some people have post the size here. All I did was I went to the metric section and picked out a nut that fit the original screws. Then found the mate in size for a small bolt. From what I have read I believe that cap screws I think thats what they are called if not excuse me would work best eventhough I used the bolts. What i had to do with the bolts is machine a 7mm sockey down around the outside to help clear the bowls when trying to tighten the socket hits the bowls and gives the false impression of being tight or that they are crossthreaded. AFTER REPLACING THE SCREWS IT WOULD BE BEST TO DO IT ONE BOWL AT A TIME. I take one apart jet it, put back together and then take the other bowl off. I do this to make sure i dont hit the other float when not working on that side and knocking it out of whack.
12. Ok now you are ready for gets the main jet is easy to identify its nearly in the center of the bowl with a collar on it. Take a regular screw driver and the correct size wrench to hold the base in place, break the jet loose. In some cases you dont need a wrench at all just use the screwdriver but if you see the entire main jet assembly spin you will need to hold the base in place. Take the jet out of the collar and put the new one in it and replace it. Now replace your pilot jet. Im assuming you already have it before you do this so just match it up to the correct jet I dont know how to explain this one other then its a longer jet and will be marked 22.5 i think. Do not overtighten the jets, just make sure they are snug.
****Left carb gets the smaller jet/Right gets the bigger jet****Hence the sayings like 165/170 L/R Left also being shifter side or this is in respect to sitting on the machine. Or keep in mind you can always look at the jets that are in there if stock its 140/145 self explanitory which one gets the bigger jet.
13. Reinstall the bowl with new screws/bolts I HOPE(An absolute MUST, sorry cant stress that enough). Reapeat steps 12 and 13 for second carb.
14. Jets are in, floats are adjusted, bowls are tightened. Now adjust your fuel screw on the bottom of the carbs (not sure what side) I think its motor side, to whatever setting you wish to use. Turn them all the way in not tight just snug then back them out to what you said you are going 2.5 turns. Reinstall the carbs once again make sure the clamps are VERY loose, push the carbs back into the intake boots bolted to the motor. Inspect them closely to make sure they are seated all the way on all the way around the carb. You can tighten these now if you would like. In tightening these I tighten as tight as I can get them which is why I said use a T-handle allen wrench, the standard wrench just doesnt give you enough leverage. Now you can replace the other boots pull back on them and push down its not hard but when you get the technique for it, its even easier. Now inspect those boots closely for them to be seated properly. Tighten all the boots as tight as you can get them(my opinion but I have never had a carb blowoff yet). I tighten all clamps so that the clamp starts to bottom out on the spacers for all of them. If you dont have access to T-handle metric allen wrenches you can still use the standards but what i did was I took a small closed end wrench and put it around the allen wrench and used it for leverage. Now that they are all tightened inspect them again to be all seated correctly.
15. Connect the 2 bigger hoses to the carbs and the one small one to the center. Fold the cover over the carbs replace the tank connect the gas line turn on the gas. Check the float levels again to see if they are in spec now, if they are in spec tighten down the tank. Now setup the airbox however you are gonna run and take it for a ride.

 

Slowwarrior darn near wrote a book on here.... It might be a lot of reading but between the two of us we have ripped the carbs out of both our quads countless times trying different jetting combinations for different weather conditions. Changing out the screws to bolts on the bowls should be a must.... but that is up to you.

 

Slowwarrior mentioned my jetting as being staggered. Just to show you that you might have to try different jetting combos. K&N recomended with there lid for stock raptors to go 150 / 170 or 155 / 175 so with a pipe I am trying 165/185. We have posted on here about the stagger between carbs and know one has ever heard of it but its worth trying. Hopefully you nail your jetting the first time and save yourself some time. Have fun with your pipe you'll for sure notice a big difference

 

Thanks so much for the help guys. Last night I went home jetted it. Here is my setup. 170/165 with 27.5. I am running a Big Gun full system with pro design filter, I am also using the outer wear. I am running with the lid off.

Here are the results…

Bike idles like a charm. Runs perfect.

1st gear is unreal, huge traction problems.
2nd gear pulls whellies like crazy, I just tap the gas out of idle and it pulls the front end up.
3rd feels a little weak, it will backfire if you let off of the gas.
4th and 5th I had a hard time testing because by the time it gets into 4th I ran out of road.

I put it into 4th and 5th gear but they were at lower RPMs, they seemed fine. I would not have been able to tell if they were weak or not.

I am going to pull my plug tonight. What do you guys think?

Thanks so much for the help.

 

Anyone have any ideas?

 

Sounds like you could possibly be a little lean with the pop on decel. Try rolling at a decent speed enough to not stall in fifth gear. Then gradually go through the throttle. I think you need to be able to run it through that gear or maybe try fourth to get a true reading. Then for a plug check you got to run it hard through the gears then pull in the clutch and shut it off immediatly to get a true reading, then check it.

Please tell me you got to use those instructions before you jetted or did i post it for nothing????LOL

 

I did get them, and thanks by the way. I was going riding last night and thats why I went to try it.

Thanks again. I am leaving work in a few minutes to try that test.

If it is lean, by adding the lid back on the box should it get worse or better? Better right?

If I am lean I am shocked. Big Gun told me to run 155/160 with the lid off I am running 165/170!