[smbkk]

I'm looking for help in getting a custom pipe made up. This is not for a regular Kawa dirtbike but for a KR150 that I've converted.

I've had a pipe custom made, but think the diameter is a bit small where it comes from the engine. I can get it changed, but would like some help before going ahead.

For those wondering, the reason for the conversion is because I'm living in Thailand were imported dirt bikes and their parts are very expensive and difficult to come by.

On the other hand, there are many cheap second hand 2 strokes over here and no shortage of mechanics or parts. There are also motocross racing classes with the limitation that bike must be locally made.

 

[smbkk]

^Thanks, actually I was after something a bit simpler. Maybe a standard pipe design from a KDX. The guy doing the work does a good job, but he's not familiar with the technical aspects.

I was told as the pipe comes out from the engine, the diameter should remain the same for about ten inches, then start to taper out and the taper at both ends should be about the same. Does this sound correct?

Any tips would be helpful, I'm not trying to make the perfect pipe, just something that works.

 

[smbkk]

^Thanks again, your correct it was a street bike. I still have the originally pipe, so I can get the dimensions from that.

As I understand it, the street bike pipe would have a longer taper than a dirt bike. Does this sound right? If the diameter of the custom pipe at it's widest point, matched the diameter of the old pipe, would this mean it's (more or less)wide enough?

Below are some, pics:

 

[smbkk]

I've checked the original pipe against the custom one, the new one is 1.5" less in circumference.