07 wr 450 with fmf slip on ????

Installed my slip on last night, done all the other mods before ais,jd jetting,small baffle. anyways i took bike for about 10 miles tonight, not sure what to think about exhaust. Bike actually felt slower and like it did not pull as hard.

anyone else running one on the 07's

thanks

Did you jet the bike before or after you installed the new pipe? It's my understanding that the FMF exhaust will flow better than the stock exhaust. And that will change your fuel to air ratio.

I bought the Ti Powercore and I felt the difference. I do have JD Jetting , AIS removal but haven't done the airbox or gray wire mod yet.

I jetted last week with knwoing i was getting the exhaust , i put jd's kit 165 twin air filter with dust cover, removed airbox baffles.

not sure what im will do, maybe sell it

I put mine on last Friday afternoon and then left for Hatfield and McCoy in West, By God Virginia. I rode it for the first time in the mountains. The thing was a tractor and I felt like it pulled much better than before. Which one did you get?

I'm at 1000' - 3000' and Pilot 165, Red position 4, Main jet stock, Twin Air and Cover no airbox mod or gray wire.

I jetted last week with knwoing i was getting the exhaust , i put jd's kit 165 twin air filter with dust cover, removed airbox baffles.

not sure what im will do, maybe sell it

Thats your prob.

The 165 main works well with the stock pipe/pmb combo, but a straight through pipe needs the 168 if not the 170 in conjunction with the 48 pj

chevytrkn1, unfortunately, it appears you did something wrong (IMHO). Your bike should run like a tank after these mods. All of us who have slip ons (I did the Q4), see night and day difference in the bike. A gentleman in a prior thread wrote how an 82 honda xl 500 would out pull his 07 WR. Common sense tell us something is wrong, and indeed in his case he found he had a bad CDI only after he had to climb up the dealer to get him to do something about it. I think your in the same boat. Something is not right, and it may be in carb. Did you install everything properly.

The 07 WR450 is a dog with the stock pipe (unless you cut out the restrictor). AIS removal, New pipe, jetted, grey wire...holy cow!

Good luck diagnosing. YOu have some good experts in this forum.:thumbsup:

I installed the FMF speed slip on. I can feel an increase in all gears.I did all the mods,plus jetting. I didnt have to do additional jetting .Chevy truck, take your bike in to your dealer and let them put in on their computer and adjust your jetting. Its a minor cost , and youll love the new power.

Thats your prob.

The 165 main works well with the stock pipe/pmb combo, but a straight through pipe needs the 168 if not the 170 in conjunction with the 48 pj

I found the 168 MJ to be too rich for me (FMF Factory 4.1 with a megabomb). There was always black soot at the tip of the muffler and the plug was extremely sooty black. I changed to 165 and it help some, but with the 162 the plug is a nice rusty red. I also run a 48 pj at 2500-3000 feet. I suppose the megabomb header could be the difference:excuseme:

I am running the FMF factory 4.1 with all free mods and 170 main 48 pilot and 1.5 turns out on fuel screw! Runs just as strong as factory YZ!!!

I love my bike!!!!!!!!!!!!!!!!!

Bike ran great without the slip on, i got the powercore 4. I cant imagine jetting up because what ive rad on here many people even at less elevation are running 165 main with a slip on. my riding starts at 6000-11000

thanks

Try the 165 main 45 pilot and 1.25 turns out on fuel screw!

I found the 168 MJ to be too rich for me (FMF Factory 4.1 with a megabomb). There was always black soot at the tip of the muffler and the plug was extremely sooty black. I changed to 165 and it help some, but with the 162 the plug is a nice rusty red. I also run a 48 pj at 2500-3000 feet. I suppose the megabomb header could be the difference:excuseme:

Really? WOW!

I have the stock muffler (internals intact) with the pmb insert and the 165 works very well. I assumed that a wide open pipe would require a 168 or a 170. I guess I just made an ass of myself :thumbsup:

I usually ride at 1500-4000 ft.

Really? WOW!

I have the stock muffler (internals intact) with the pmb insert and the 165 works very well. I assumed that a wide open pipe would require a 168 or a 170. I guess I just made an ass of myself :ride:

I usually ride at 1500-4000 ft.

You know, it seems bikes are finicky. I run the 168 main, 48 pilot, fuel screw 2.5 truns and JDJetting red needle on the 4th clip. I have the AIS removed along with the snorkle and grey wire removed. I also have the FMF TI Powercore slip-on. In Gorman, you go from 3,000 to 8,015 and my bike never misses a beat. No backfire, no hesitaion just runs strong.:thumbsup: Strange thing these bikes:thumbsup:

He never said which FMF slip on he has? We are all guessing!

Big difference between the powercore and the Q

He never said which FMF slip on he has? We are all guessing!

Big difference between the powercore and the Q

ahh yes however even a Q2 flows better than stock

I didn't take into account elevation in my original response:bonk:

Ya i said it was the powercore 4, not the ti. one but the other guess stainless or aluminum. ill give a good run over the weekend. seems as strong on top but like it lost some mid.

Did ya check your swingarm?

Put new Eibach springs on today (5.8 shock / .50 forks) per Jeremy Wilkey (MX-Tech) and .40 leak jet. We'll see!

Is the FMF Powercore as good as the other FMF slip ons? I want the best power boost but not obnoxious noise. I see they sell a quiet insert for it. Is it so restrictive that they did not build it in from the factory?

I have the Ti Power Core , have not done the gray wire or airbox mod and feel the box has a lot more low to mid range torque.

I also have the "Quiet Core" just in case and it is much quieter. All it is, is a maybe 50mm pipe that is maybe 60mm long that insert into the can. I can't comment on the power loss with the "Quiet Core" insert.

The bike sounds great too!

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