OzVMX Forum

Clubroom => Tech Talk => Topic started by: Slakewell on April 15, 2011, 08:09:09 am

Title: Correct core ID for a 400 Muffler
Post by: Slakewell on April 15, 2011, 08:09:09 am

What is the correct core size for a 400 or open class muffler?

Title: Re: Correct core ID for a 400 Muffler
Post by: GMC on April 15, 2011, 10:03:49 am

The specs of the stinger can vary with models, pipe specs and porting.
A good rule of thumb is that it should be the same internal size as the stinger tube on the end of the pipe.
I just had a quick look and generally my pipes fall in around 25 - 29mm ID
Some are bigger for 465's etc

Title: Re: Correct core ID for a 400 Muffler
Post by: Slakewell on April 15, 2011, 02:54:53 pm

Thanks for that , I know it's hard to know for sure.
I'm just about finished my 77 KTM 250 only to be told I can now have a 400 engine that's just turned up.
I have all the parts for 250 and a lovely little DG muffler that's 25mm ID. I will now have to make another pipe for the 400 etc so I'm still unsure 77 KTM 400 are rare and wonderful thing thou and having a nice race ready one will be cool.

Title: Re: Correct core ID for a 400 Muffler
Post by: Lozza on April 15, 2011, 10:56:28 pm

Are you trying to achieve a specific goal?

Title: Re: Correct core ID for a 400 Muffler
Post by: Slakewell on April 16, 2011, 08:28:14 pm

Mostly if I can use the DG muffler as I have already modified it to suit the bike, as I haven't made the pipe yet I can make it fit the muffler.