PDA

View Full Version : Exhaust "popping"



Stryker1513
04-08-2008, 02:56 PM
I have a FMF 4.1 slip-on, JD jet kit with set up with how they recomend, 180 main, 45 pilot, red needle, and an r&d power bowl. And my exhaust pops really loud when i let off from WOT. Any reasons/Solution?

patrickj75
04-08-2008, 04:26 PM
maybe a bigger pilot. whats your fuel screw at?

Stryker1513
04-08-2008, 06:08 PM
2 turn out

patrickj75
04-08-2008, 09:34 PM
on my Honda with a pipe i ran 180 main, 50 pilot and about 1-1/2 turns out. i'm at about 950 for elevation.

mcracer
04-08-2008, 09:43 PM
I'm running 4.1 w/ mega bomb using 48 pilot and 175 main 2 turns out and no popping at all.

atvrider23054
04-16-2008, 05:20 AM
you have an exhausst leak like me take it back to the dealer

inthewoods10
04-28-2008, 02:13 PM
Ktm notourious for exhaust leaks, look at all your exhaust joints, if you have black soot you've got a leak, biggest problem is at the head, i used rtv hi temp gasket seal works for a while but will eventually blow out, when it starts back firing again on decel i just re apply more sealant, solved the issue for me!

tapper torney
05-02-2008, 07:52 AM
I've got the exact same problem (leaking at the header) . Annoys the hell out of me, especially since i have rarely seen this problem on the bikes. silicone is only temporary as you say !!!!!!

05-05-2008, 07:48 PM
Heres what a guy did to fix the leakage.

http://i224.photobucket.com/albums/dd127/blue450yo/dum/28j8f1v.jpg

thump4863
05-06-2008, 07:09 AM
Originally posted by bajaracer21
Heres what a guy did to fix the leakage.

http://i224.photobucket.com/albums/dd127/blue450yo/dum/28j8f1v.jpg

I would not weld like he did - that can cause major issues down the road.

OutlawBill
05-06-2008, 07:44 AM
If it is leaking at the weld why would re welding hurt as long as you due not warp it. Has any one tried JB Weld.

thump4863
05-06-2008, 08:12 AM
Originally posted by OutlawBill
If it is leaking at the weld why would re welding hurt as long as you due not warp it. Has any one tried JB Weld.

What he did was not reweld. There is a plate that mounts to the motor and the pipe just fits on this. He welded the plate to the pipe making it rigid when its made to flex.

OutlawBill
05-06-2008, 08:28 AM
looks like he weld the exhaust flange that bolt to the head and the exhaust pipe fit in too and held on by the springs. If tis is the point that is leaking there either the gasket has failed or there are holes in the flange. Checking out J-B weld will not work only goo too 500 degrees F but PERMATEX® Hi Temp. Metal Repair Compound should work good too 2000 degrees F

Boytjie
05-13-2008, 12:43 PM
Hi Guys... my 525XC started to leak whilst XC riding in the desert (70min from car), noted the bike lost power. As soon as I stopped, found the bike boiling (6 hours on the clock - thus brand new)

Found the exhaust leaked, hot exhaust gasses blowing onto water cooling hoses. After drama getting it back home, send quad to KTM. They done an exhaust weld, I am still waiting for KTM (Austria) letter stating that they approved it. I am concerned that the flexed exhaust is now ridgid with the original header bolts (quite small) - this might caused later on due to ridgitdity the header bolts to break... worse transfer the stress now somewhere else (the head itself, might lead to cracking)

Comment are welcomed...
Cheers,
Boytjie