good luck man

 

Ok, the rebuild is done and the bike is running. Putting the carb back in was challenging, but not nearly as bad as trying to get it out.

I took it for a ride and I get smooth acceleration throughout the whole throttle range. When I brought it back I re-adjusted the idle and it purrrs fine.

But I'm getting some popping when changing gears or downshifting (RPMs dropping). I was having this problem after I installed the Q4. I noticed yesterday before starting the rejet there were puffs of air coming from the header-muffler joint. Admittedly, I used a silicone spray when I first put it on because I didn't have any high-temp silicone on hand as the instructions say. But yesterday I pulled the muffler and put on a good bead of high-temp silicone hoping that would stop the small leak. I didn't run the bike yesterday so it had plenty of time to set. So I was surprised to feel air coming from the joint again today. About the same amount as before.

Is that why I'm getting the popping? I thought I put a good amount of sealant around the header, what I am doing wrong? Should I try and tighten the bolt some more? I don't want to over do it and **** it up. Is there a torque setting I can use?

Hopefully this popping is an exhaust leak and the rejet has nothing to do with it.

 

I dont think the leak at the pipe joint is the cause of the pop on deceleration.You might try to turn the air screw out 1/4 turn at a time and see if it reduces the pop.

I couldnt find the exact torque for the muffler joint clamp in the service manual. If you really want to get rid of the leak at the joint I would rotate the clamp so that the V notch in the clamp is between one of the four sections created by the four slots in the header pipe (black stripes in pic) and also make sure the sealant is in place at the red oval in pic.

I dont know if any of this free information will help but it is free. The experts will be along any time now with professional advice

 

Also, silicone spray is a lubricant not a sealant. Make sure you clean both surfaces of the muffler/headpipe joint with a cleaner such as brakeclean, acetone, etc. before applying your HT silicone.

I think a small amount of popping upon deceleration is acceptable.

 

Also, silicone spray is a lubricant not a sealant. Make sure you clean both surfaces of the muffler/headpipe joint with a cleaner such as brakeclean, acetone, etc. before applying your HT silicone.

I think a small amount of popping upon deceleration is acceptable. Double check the seating of the carb into the rubber intake boot/manifold as well as the band clamp.

What main jet (DJ) did you install?

 

I used the 128, clip on the 3rd slot with 3-turns out.

Should I feel no air at all from the header/muffler joint? I'm going to redo it again following your recommendations. Hopefully, the 3rd time will be the charm.

If after I seal the exhaust leak and it still persists I'll adjust the fuel screw. I have yet to see how I'll be able to get to it with everything buttoned up.

 

Hmmm. I am not an expert but I would have thought that you wouldve been around the 132 main for 25 ft above sea level in Sacramento. I run a 124 at 2800' ASL.

I would also think that you would NOT want exhaust to leak around the joint between the header pipe/muffler. Eventually you will have some soot appearing where the exhaust leaks. I am pretty sure that the small leak at the clamp will not remedy the popping.

 

Hey Brein,
What I've noticed on this forum is that it seems rare when someone puts on an aftermarket exhaust and does NOT have decel pop. The header/muffler joint leak can cause it, at least it did for me. If you can get the whole exhaust system sealed up, that should help.

Here's one thing I've been thinking of lately, but don't recall ever seeing it mentioned. Did you drill the slider? That makes the slider rise, and fall, faster. If the slider falls faster, will the bike be a little leaner on decel than it would have been without drilling it? Lean conditions can cause decel pop. So this makes me wonder if the DJ kit & slide drill help contribute to our decel pop issues.

Mine pops some on decel. I don't worry about it. It's not bad. Efforts to seal between header and slip-in helped (high temp rtv).

Regarding 124 or 128 on DJ main jet size, I'm pretty sure I was running on the rich side with a 124 at same elev as whyzee. Bikes and setups and etc are different. IMO, a 128 is a good place to start at your elevation and see what happens.

 

I'm not sure what the "slider" is. I drilled out the cap over the screw as it says in the Dynojet instructions and did the 3 turns after tightening. I saw someone else mention drilling a .018 hole for the enrichment jet. It didn't say that in the instructions so I didn't do it. I followed the instructions to the T as far as Jet size and settings. In my brief time testing it, it seems to be running good other then the popping.

I re-did the exhaust again with more sealant and didn't tighten it up. The instructions on the sealant say finger tight for the first hour. So I'll finish tightening it up tomorrow. Also, when I pulled the Q4 off and went to clean the old sealant off it was still pretty sticky, like it wasn't dry. The instructions on this tube say it takes 24 hours to set. So I'll try and give it at least that until I fire it back up.

 

The dynojet kit for the 09 comes with a lighter spring and does not require drilling the slide. What is your airbox config lid on/off, kdx snorkel? Did you remove any smog equip while you were in there?