2k1w=no$ - thanks for clearing that up, you just saved me another worthless purchase. Anyone want to buy a stock 300 muffler ?

 

But the 300 muffler IS an improvement over the 250S muffler---a big one. You just need the 300 header to run it (which is why we use it).

BTW I ground the weld smooth on my header, you can not tell it was ever there running your finger across it.

 

The butt plug is also removable on the 300 exhaust which frees up some extra power. I have read that the header is the major problem on the 300(not big enough dia.)not the muffler.

 

But on the 250S there is no removeable plug (& IMHO a 1/2" drill bit wont get you there either) & bolting on a 300 muffler with no plug is pretty much like putting a slip on on the 250S. The advatages of the 300 muffler being its very cheap, its about as quiet of a modified pipe as you will find, & flows nearly as well as any slip on.

No, the 300 header does not give you any more power than the 250S header, but you need it to bolt up the 300 muffler.

On the 300 system once the butt plug has been removed the headermay be the bottleneck depending on what you want to do--some forum members have reported a stronger low end with stock headers--I dont doubt a larger header will give you more on top at all--I'm sure it will--but it has to come from somewhere.

 

+1 What klxer said.

 

My stock can only goes on if it goes back to the dealer. I already have an HMF slip-on that I got at a great price (and I am happy with) so I might just think about the powerbomb....although I haven't seen any reviews on it yet. I guess I could always start another thread!

 

Hope it's on point enough, is the 300 kit the stock parts from Kawi? And is it very difficult to instally yourself if you're not a top notch mechanic?

 

Yeah, if you're going to 300cc, it's normally done withall stock parts...unless you opt for the Wiseco piston, ala KLXer(that's probably the route I would go).

Do a search for 300cc upgrade by Nobrakes. That should tell you whether you want to do it or not. Basically, you will need the service manual, a torque wrench, assembly lube and a ring compressor of some sort along with yournormal tools.

The job will require removal of the head, cylinder, and piston. You will also have to come-up with a way to prevent the timing chain from dropping into the crank case when you remove and replace the head (people usually tie something to it for easy retrieval).

If you've done that type of work before, it should be a piece of cake. The most critical part is getting rings in the right place, torquing the head properlyand making sure the cam timing is correct when you put everything back together.

Also, I think at least two forum members managed to put a hole in their radiator while doing the large bore upgrade, so I guess that would be something tobe particularly mindful about.

 

Hawaii Rider, Check out this link..read the whole thread...very informative piece by Nobrakes, complete with pic's.

https://www.kawasakiforums.com/m_492..._1/key_/tm.htm