MCX Apex boggy, popping, etc with 17lbs boost mapping

[tom]

My MCX apex ran spot on with the 12lbs mapping, but since I've had it remapped for 17lbs its real boggy. Sometimes off idle when I get on it, it bogs so bad it just bogs out (sometimes dies) and I have to get out of the throttle and chop it a bit to get it cleaned out. It also has some popping sounds around 5-8k RPMs, power feels good but it doesnt sound too great. Above that runs fine. What could it be? Is this common?

 

[Trxster]

Did it run right at all when you first did the remap? If so, you may have split or popped a vacuum line. Mine pops quite a lot when a line degrades or falls off.

Rt

 

[ken_climb]

Tom, have you checked your header pipes like I told you to do? Time to drop the skid buddy!

 

[summitking]

sled

Tom do you not have the stainless headers?Does the sled burn much more fuel with the 17 lbs mapping?

 

[tom]

Tom, have you checked your header pipes like I told you to do? Time to drop the skid buddy!

That could be it, i'll check it out.

 

[tom]

And very nice icon by the way

 

[tom]

I just checked the headers and they look good. I mean they would be pretty warped and very obvious if they were causing problems right?

What else should I check?

 

[ripntear]

Do you have the spacers out of the throttel body clamps, if not you are starting to push the throttel bodys off the intake boot. We had this happen to an Apex this winter and it took for ever to figure it out. It won't blow off just flex enough to make it run like crap. We took the spacers out and it ran great.

 

[tom]

I should clarify that it still makes good power. Just takes a little to clean out on the bottom end, pops a bit in the mid range but still makes good power and rips wide open as it should.

 

[summitking]

sled

Maybe its running a bit to rich.Theres a few guys who have leaned there sleds out a litel bit with the boon dockers box.cheers

 

[4strokes are better than2]

4 strokes & poping usually its lean.but with the apex it could be a few things.causing 1 prob look for any lose lines or any that have come disconected.i seen quite a few apexs at bis doing the same thing.

 

[ken_climb]

The stock exhaust flanges that bolt to the motor sometimes crack on the rear mounts. Tom when you had your skid dropped did you fire it up and listen for exhaust leaks? I've heard of at least one mcx y pipe cracking.Any type of exhaust leak would create a sluggish bottom end. As for the popping, its likely the rev limiter. I find it really hard not to hit it with spring compact snow.

 

[tom]

I didn't fire it up, so it could be a crack. I don't think the popping is the rev limiter, cuz its definitely within about 5k-8k RPM range. When I crank up the boost and open it up it hits the limiter.

 

[rxrider]

What is your CO set at? You could try it at -5 to start with, you may have to go down more if it doesn't cleat it up. The CO settings is acting like the pilot jet and screw on the carbed sleds.

The procedure on how to adjust the CO was posted here by HAMMER, check out this thread

www.ty4stroke.com/viewtopic.php?t=23339 ... t&start=15

 

[rxrider]

I didn't fire it up, so it could be a crack. I don't think the popping is the rev limiter, cuz its definitely within about 5k-8k RPM range. When I crank up the boost and open it up it hits the limiter.

If you hit the rev limiter you have to load more weight in your primary to keep it off. My sled did the same popping in the mid range rpms when running the stock weights hitting limiter at WOT after 3-4 sec. When I got the Supertips in loaded up with about 88.5 grams the midrange cleared up. My take is that it lean pops when the engine is not loaded enough caused by too light primary weights. Just my 2 cents.