Murphyau wrote:
Stiletto 150 wrote:
Also, one thing to keep in mind is that these figures are for a bone-stock ZRX. It is really easy to pump this mill up in any number of ways (the Rex crowd are seriously deranged horsepower and torque freaks), from big bore kits to cams, h.c. pistons, turbos, etc.
Dan
Dan, As I mentioned to you on COG many months ago, you won't be disappointed with ZRX and it would seem that you have now "seen the light ". While there are some ZRX devotees who are mild mannered enthusiasts who only ride the ZRX to church on Sundays and never exceed 3000 rpm, there are not many.
The ZRX is ultimate "sleeper". It makes a perfectly good touring bike with the addition of some soft saddle bags, yet can stick with the majority of tupperware sports bikes through the back country hills on a Sunday morning sprint.
Modifying a ZRX is like a desease. It all starts with fiddling with the stock jetting, then its Ivan's needles and a then full exhaust system and low and behold you have hp and torque gains through the complete rev range with probably another 20 hp on the top. Then you get serious, HC pistons, big bore kit, lightened crank, ZZR cams, until you finally fall ove rthe edge and get the turbo. At the moment, I am still saving the pennies for the crank/cam/big bore mod.
Mind you, while I have modded my ZRX a bit, Ive tried to balance the power gains with inprovements in the handling. Decent tyres ( I run a Metzler M3/Z6 combo) and the front forks, which I see you have also grafted onto your ZGRX, really do need Racetech Gold valves (pre-2004 models only, post 2004 cant be reworked) plus new fork springs and while you are at it, one of Greg Couch's fork braces does make a difference (IMHO).
The other thing that you may seriously want to consider is fitting one of Kwick's Tip Over switches ( which is a modified R1 switch ). The ZRX engine has a nasty habit of running #3 conrod bearing if the engine is left running on its side for more than a few seconds as the oil pump starves.
Only request I have is that if anyone ( here in Oz or in the US ) decides to duplicate your project, please use a crashed out ZRX and not a roadworthy bike. I saddens my heart to see a perfectly good ZRX dismantled.
There are so many excellent methods of improving the Rex engine performance, I have much to look forward to in the years to come. A tip-over switch is a good idea. My 1979 Yamaha XS-1100 had one as well as self cancelling turn signals.
While I do very much agree with your sentiments above (in italics), and believe me, I asked the same of an individual that I sold my 1970 Honda CB-750 (please keep it stock and preserve it for the future) I had a set of good reasons to do what I did.
I began this quest looking for just an engine. None were avalable at the time and I looked for a couple of months. In addition, I was not too keen on buying an engine for sale not knowing why, exactly, it was sitting on someone's bench for sale. I could not hear it run or know anything about it's condition other than the reports of the owner. In addition, I needed many other ZRX parts. Forks, wheel, brakes, master cylinder, carburetors, airbox boots, ECU, ignition triggers, alternator, starter, ignition coils, most of the harness, etc. I would have had to shop for these individually. Also, on top of all this, I had never ridden a ZRX before. I needed to run road tests to confirm my intent to use this engine for the project.
I did have the blessing of the person who sold the Rex to me, but I have to admit, I did not tell him of my intentions until after I announced the project on the Concours owners Group forum.
I tend to look at it this way. I cannabilized a good ZRX but the heart goes on living within the Concours in magnificent fashion. Those that crash and destroy a good ZRX, especially by being completely irresponsible deserve no sympathy. And there are many of those out there who have done just that, total them out of commision altogether. At least this project has provided a source of parts for a completely unique motorcycle. And the rest of the parts found good homes with ZRX owners who needed them to get there's running and on the road again. I sold all of the left over parts to a long list of dedicated Rex owners who needed a little help to get their pride-and-joy motorcycles rolling again. It was very much appreciated by the recipients. I feel good about it.
Having said all that, I do agree with you and very much respect your position. I just wanted to articulate mine.
JMHO
Dan
