Kawasaki Sportsbike Riders Club - Australia - Online Forum

I awoke this morning gripped by the sudden and desperately urgent need to tinker. It is a sad and debilitating form of OCD that grips us all to certain degrees and medically speaking is directly attributed to long term motorcycle ownership.

I am sure you know what I'm talking about. How many of you remember getting a brand new bike home and not being able to sleep properly till you at least 'got it nekkid'. (took off the plastics and had a look around.)

Well I am no different. I bought "G-rex" (a pet name for my gpz1000rx which I in my own wankerish way believe reflects both it's age and nastiness. ie. a dinosaur of sorts with a very nasty bite)
about a month ago and have been learning it's ins and outs since. It usually takes me about 3-6 months before I am 'happy' on a bike and have learned it's little idiosyncracies.

G-rex is largely schmiko. Very good condition for a 20 year old suffering only from 80s suspension and weight. (a little overweight and very stiff - a bit like me.) The only other thing that has shit me since i rode it home has been the exhaust. In typical old kwaka fashion it is constrictive and quiet. It sounds like a very angry sewing machine.

This is what I attempted to address this morning.

I removed the mufflers and took them to the workshop... (a table in the carport next to half a dozen industrially deaf parrots and budgies.) I then proceeded to drill out the rivets in the end caps to examine the interanls and hopefully let the poor thing breath a bit. An hour later after much tinkering i saw in also typically kwaka fashion that the whole show was much over-engineered and going to be a bitch to modify.

Back to the drawing board.

I re-riveted the end caps and opened a beer. I sat and looked at G-rex reclining on the grass and wondered how I was going to open up the pipes a little.

Then it struck me.

Pics attached.

Worked wonderfully, not too loud, not too quiet, and a little less restricted.

you bashed a hole down the middle?

Well if you want to put it that way.....


I 'carefully' bashed a hole down the middle.

The internal baffle is blanked at the motor end with a thin sheet of .5 mm steel forcing all exhaust to filter through the packing and then a bunch of tiny holes. I simple, ahh... opened up the blanking and left the baffle otherwise intact.

so does it roar now ?

nice and grumbly at idle.

throaty like an angering man in the midrange

and raw like a woman gripped by orgasm in the top end.


Swear it's found an extra couple of ponies too....


ED; no flat spots either.

Get the AF ratio checked, as it is probably running a bit lean now.


Neil

It's great to see all the exaust shops spend massive $$ on these things, when all you need is 50pound sledge hammer and a piece of pipe.

Unsure if yours has the muffler sticker (ADR bullcrap bloody thing) regarding silencing system, but it's kinda still ok as it isn't aftermarket muffler

Good to see some RX's on the road. Mine had a Formula 1 System out of Brisbane (from memory). sweet...
Oh and Animal Planet reckons T-Rex was a scavenger, not a predator, so you may want to look for some decent brakes (what yours DIDNT warp???).

brakes are ok for an oldy. The front disks had been replaced and machined for roadworthy, new pads etc. Only just got them bedded in and biting properly. Was looking down the track at replaceing the wheels to get 17'' s will look at the brakes then too.

dont think I'll need to re-jet the 'mod' was actually pretty minor and just frees up a little bit. no flat spots, will keep an eye on it tho if it's gonna be a bit lean it will be in the top end

Nice!

Might go have a closer look at the GPX......

thats not a real tool kit...i didnt see a single zip tie or roll of gaffa tape...