Dr. D exhaust clamp?

[chrisford4x4]

My bike seems to be popping real bad on decel. I don't think it's my fuel mixture as I can see and feel exhaust coming out from the connection between header and mid pipe. Anyone used a clamp on these dr. D system designed without and what did you use? I don't like the idea of gooping silicone all over it either.

[GHILL28]

I've wondered about this too.  I don't like that interface at all on mine.

[ThumpMe]

Real bad popping on decel can be a sign of a leak where the header bolts on to the head. Replacing that gasket USUALLY will fix it.

I do not have A Dr. D exhaust but have had to make new seals for the mid pipe connection on several bikes in the past.

I copied the design that was used on a KLR that had a Big Gun exhaust on it. Turned a piece of Aluminum on a lathe so it would just slide into the gap between the header and mid pipe and then used an exhaust clamp off another pipe manufacturer that was the right diameter to clamp it.

Worked good!

[jcm3]

Did you happen to call or e-mail DRD for their input?  I did on mapping, and they were super responsive.  Maybe they have more info that would help if someone doesn't find the solution before then.  ?

[cowboyona426]

My bike seems to be popping real bad on decel. I don't think it's my fuel mixture as I can see and feel exhaust coming out from the connection between header and mid pipe. Anyone used a clamp on these dr. D system designed without and what did you use? I don't like the idea of gooping silicone all over it either.

 

I never did like that slip-fit design.  I would try a band clamp on it, that's what I was going to do but never got around to doing.

 

[chrisford4x4]

Just got done putting on a stainless steel t bolt clamp. Seems to work good after a couple relief cuts. Although I think I have an intake leak between the carb and head. I have to run the pilot screw four turns out and the idle increases when the area is sprayed with carb cleaner. The idle hangs a little as well. Hoping third times a charm. Valves were all nominal except for one exhaust is at top end so glad to see that.

[chrisford4x4]

Real bad popping on decel can be a sign of a leak where the header bolts on to the head. Replacing that gasket USUALLY will fix it.

I do not have A Dr. D exhaust but have had to make new seals for the mid pipe connection on several bikes in the past.

I copied the design that was used on a KLR that had a Big Gun exhaust on it. Turned a piece of Aluminum on a lathe so it would just slide into the gap between the header and mid pipe and then used an exhaust clamp off another pipe manufacturer that was the right diameter to clamp it.

Worked good!

Is there suppose to be a gasket between the head and header? I believe mine is metal to metal.

[grayracer513]

Yes there is.

[ThumpMe]

Yes, they are made out of that weird sort of silvery high temp fiber material with a thin copper sheet metal on both sides. They crush down pretty easy to conform to any misalignment or gaps between he head and pipe to seal it off.

Most say to replace EVERY time the header is removed, but I sometimes use them again and have had mixed results.

If you do not have a gasket there, or it leaks, I bet that is the source of your popping on decel.

What happens is as you roll off the throttle, it will suck in air at that point, the addition of new fresh oxygen into that high temperature will cause it to pop as it burns off any unburned fuel it finds there.

Edited March 19, 2015 by ThumpMe

[ThumpMe]

I noticed in your picture you have a pretty dented head pipe, since you have to remove it to replace the gasket you could straighten that out while it is off.

Real simple way to do that is to pour a little water into your pipe and then set it up in a freezer so the dent is located in the center of the water. As it freezes the ends will freeze first and then it will ice up more and more towards the center where the dent is. As the last bit of water freezes it will expand and push the dent out.

If you have a good freezer set to zero or below it will usually take about an hour and half to completely freeze the water. Then remove it and run hot water into it to melt out the ice plug and do it again.

Usually has to be done 4-6 times to completely remove the dent, (depending on how big the dent is, and what material the pipe is built out of) but works like a charm!

[grayracer513]

Regarding the header gasket for the exhaust port, I make my own out of a piece of 8 gauge bare solid copper ground wire (any hardware store).  Cut it so that it's just short enough to roll into the port pocket with the ends butted.  It's reusable, available, and dirt cheap, plus, it doesn't overhang the seal seat and extend into the exhaust path the way the OEM seal does.  

[cowboyona426]

Is there suppose to be a gasket between the head and header? I believe mine is metal to metal.

 

I replaced that gasket not that long ago, it can't have more than half a dozen rides at best since I put the new one in.

 

I noticed in your picture you have a pretty dented head pipe, since you have to remove it to replace the gasket you could straighten that out while it is off.

Real simple way to do that is to pour a little water into your pipe and then set it up in a freezer so the dent is located in the center of the water. As it freezes the ends will freeze first and then it will ice up more and more towards the center where the dent is. As the last bit of water freezes it will expand and push the dent out.

If you have a good freezer set to zero or below it will usually take about an hour and half to completely freeze the water. Then remove it and run hot water into it to melt out the ice plug and do it again.

Usually has to be done 4-6 times to completely remove the dent, (depending on how big the dent is, and what material the pipe is built out of) but works like a charm!

 

You should have seen the header before I did the freezer trick... I took it in and out at least 8 times and the dents stopped moving after about the 5th time so I called it good enough.  FYI, this is my old bike.

[chrisford4x4]

I guess I should look at it next time I have it off. I honestly never payed much attention. It's probably been ten times now I've had it off to try different things. Thinking about wrapping it to cover dents and to keep from incinerating everything. Not sure how it will hold up but it's always fun to experiment.

[cowboyona426]

Sorry to hear you're having such a hard time with the old girl, hopefully all the tinkering pays off in the end.

 

I got to thinking about it and I can't remember if I gave you the stock flywheel or not; if not I'll get in touch one of these days and get it to you.

[chrisford4x4]

Ahhhh can't expect to much for being almost ten years old. It's still a solid bike just needs some attention. Although I've been said to be anal with things.

[cowboyona426]

Did you sell your Kx I saw it was for sale?

 

No, still have it and it will probably end up staying around because I don't want to take a huge loss on it.

[ThumpMe]

Regarding the header gasket for the exhaust port, I make my own out of a piece of 8 gauge bare solid copper ground wire (any hardware store).  Cut it so that it's just short enough to roll into the port pocket with the ends butted.  It's reusable, available, and dirt cheap, plus, it doesn't overhang the seal seat and extend into the exhaust path the way the OEM seal does.

THAT is darn good idea....you cannot beat ALL metal as it does not cook away like that silvery fiber material does.

So you have not had any problems with it sucking air where the two ends butt together?

[jcm3]

THAT is darn good idea....you cannot beat ALL metal as it does not cook away like that silvery fiber material does.

So you have not had any problems with it sucking air where the two ends butt together?

 

I was wondering the same thing, but seems like a great idea.

[grayracer513]

If you fit the wire into the pocket at the right length, with the ends even just touching, the ends will be forced together as the copper compresses when you tighten the header flange.  Even if they don't quite seal, there should be very little tendency to leak anything significant. 

 

As cheap as the bare wire is, get a little extra so you can screw up the first two.  ?

[ThumpMe]

I replaced that gasket not that long ago, it can't have more than half a dozen rides at best since I put the new one in.

 

 

You should have seen the header before I did the freezer trick... I took it in and out at least 8 times and the dents stopped moving after about the 5th time so I called it good enough.  FYI, this is my old bike.

I found on one bike that has a Titanium header (Ti is pretty soft metal) that it is real easy to freeze dents out. Real easy to get em back too!

On another scoot I have a stainless steel header. Yours looks stainless from the pic. MUCH harder to remove the dents. Found that if you use more water on each side from the center of the dent it will work better as the plugs freeze on each side get stronger the longer/thicker they are. This causes the final freeze/push to occur more in the center as it can no longer crack the ice out to either end due to the thicker/longer ice plug.

I just did finish up a brand spankin' new pipe guard on another bike I picked up last year. Vowed I would not ride it till I built a new guard because without a good guard on there I found out I ALWAYS burn up pants! Not while riding...while trying to squeeze through trees or rocks or move a bike around manually! Or picking a bike up! SUCKS as new pants are a over a hundred bucks!

I wanted it long enough to wrap around the front of the TI pipes as they always seem to get dents there from rocks thrown up by the front wheel.

It came out real sanitary!