ZXR 750 M frame and engine nos

[Fifer]

Yes, it's had a fair bit of lightening done already - but there's always room for more. An alloy gas cap and one of the super lightweight lithium batteries are the obvious quick ones to do (I've heard conflicting reports about lithiums not working for total loss but a mate is running it and so far so good)

The ZXR is already a fair bit lighter than the VFR and I spent quite a bit of time getting weight off that. The VFR did well against better bikes so I'm hoping I won't get smoked as much down the straights anymore!

[greenman43]

It also Franks adjustable triples so it's got to be fairly one-off.

I've dyno'd it at just shy of 130, and since I believe the kits were worth 140 or so, I guess it's a mix of some kit parts and some stock M bits....or maybe there is 10bhp in ignition set up etc??

I used to have a set of Franks clamps, which I bought along with Ohlnus forks from John Phelan many years back - certainly not a lot of those clamps round (I sold my front end to a guy in Canada).

That much power suggests it has some kit internals, so - to a degree - beware. A lot of the high-stressed parts are lifed, 2-ring pistons goos for 1000 km while the 3-ring (endurance) pistons are up for 3000; beyond that, they start to crack. Kit valves will pull through eventually, so watch for closing valve clearances. The valve faces will also wear, you really need to keep an eye on this stuff. The only time I dynoed mine it came in at 143 I think, but that awasn't the best engine (at different times I had 5 kitted engines).

Cheers,
Brian

[greenman43]

I'll jump the gun and assure you that Brian will advise you to drill, file, grind, dremel or just unbolt anything that doesn't need to be attached to save weight... our steeds sure aren't lightweights!!

You know me too well, my friend But it is sound advice - you can take massive weight out of these bikes, if you're really trying hard and spending money

Cheers,
Brian

[Fifer]

Ah, unobtanium kits parts! How unobtainium are they? Is it inevitable, despite the sacrilege, that an early ZX9 motor will be the way to reliable 130+ bhp?? Given it has to race in Pre modern against early R1's etc that might be preferable in anycase?

[JimZXR]

The extra cc's would probably help as well as the extra dump of torque available but maybe worth spreading to the scruits first as they may frown upon a non standard motor running?

[Fifer]

No issues with that mod or many others, since pre modern is pretty much open slather being more or less just a club category until it becomes historic (some time away, P6 has only just been included and P5 is still huge). It varies from state to state and club to club, PCRA have a 12/95 cut-off, St George I believe is a bit later (97?) And in Vic Hartwell have just introduced P7 they're calling it, 91-2000 and then pre modern 2001 - 2004. The other series in Vic have a 9 or 10 yr rolling cut-off....Most run over and under 500cc splits, PCRA have their pre mod rules on the website, there are pre-mod rules on the Preston MCC websites hartwell have revised theirs.....dunno what other states are doing but will be similar I imagine.

The 900 motor would as you say make it more rideable although I do worry a bit about spoiling the handling, as per FZR1000 motor in OW01's and the like. On the other hand, it would be easier to get 140 safely out of a 900 than the 750 and with more reliability and longevity too I would think ...as a club bike it is useful to have a broad, decent delivery but still have some over rev.....or there are bore kits for the 750 to take it to 850 or thereabouts, assuming they can be raced, most seem to be road orientated and take a decent engine builder to make them work successfully and reliably in a race motor.

[greenman43]

ZXR engines like lots of revs (as standard and kitted), but 9Bs don't: they tend to drop valves with over-revving. If you're going to plug one of them in, either get your 750 ECU remapped to a lower rev limit, or better yet look to fit a 9B ecu. Don't know if they're plug and play, mind you. ZXR Tachos tend to read about 1000 rpm too high: is yours standard or kit?

Cheers,
Brian

[greenman43]

Ah, unobtanium kits parts! How unobtainium are they? Is it inevitable, despite the sacrilege, that an early ZX9 motor will be the way to reliable 130+ bhp?? Given it has to race in Pre modern against early R1's etc that might be preferable in anycase?

The main reason I got out of my ZXR was that I couldn't find kit pistons or valves for love nor money. Put the OEM parts back in, you lose the reve ceiling which is where the cams, pipe, ignition and carbs make the real power.

No idea how reliable aftermarket big bore kits are, I too am a believer in the purity of keeping it a 750. But realistically, if - unlike me - you ride well enough to use the grunt of a big engine to drive hard out of corners, a 9 is the way to. Just keep it fairly stock, and it should be inexpensive / reliable.

Cheers,
Brian

[Fifer]

I think the tach is stock, not sure, pic below. Not sure what ECU is in the bike either, no markings on it I can see (I really need to talk to whoever built this bike).

Are you sure you don't ride well enough to get good drive off the turns? If that's you in the pic and by the sound of how serious you've got bike-wise in the past, you might be selling yourself short!

[greenman43]

LOL, nope, that's Chris Walker on his WSB bike in the avatar pic. My motto when I was racing was "Of course, they're faster than me, they're young, fit and fearless; I'm old, fat and scared", and it pretty much sums it up. Panamanian-registered supertankers stuff inside me under brakes, and garden snails scare the crap out of me when they rocket past out of corners. I just love trick stuff

Cheers,
Brian

PS Your tacho is from a J, possibly a K. Want to post a pic of the ECU ?

[Jonnymac]

"Of course, they're faster than me, they're young, fit and fearless; I'm old, fat and scared", and it pretty much sums it up. ?

I'll give you old and scared Brian, but there's no way your getting fat....:):D

[Fifer]

Seems it might have a few J / K bits then as the engine no. on the cases in it is 750J101 etc. Pic of CDI below. Well you got me on the avatar pic I didn't recognize it as a known racer. I'm bloody glad you're on here nonetheless! I'm pretty old and scared myself when it comes to trying to ride a bike fast, it's a young man's game.

[greenman43]

Seems it might have a few J / K bits then as the engine no. on the cases in it is 750J101 etc. Pic of CDI below. Well you got me on the avatar pic I didn't recognize it as a known racer. I'm bloody glad you're on here nonetheless! I'm pretty old and scared myself when it comes to trying to ride a bike fast, it's a young man's game.

All good fun mate, as long as you're enjoying it I don't think it really matters how fast you are.

That's definitely an earlier igniter / CDI, later ZXR kit units have 3 equal-sized plugs.

Cheers,
Brian

[greenman43]

I'll give you old and scared Brian, but there's no way your getting fat....:):D

Clearly comments like that will get you on my Christmas Card list Jonny, but the sad fact is that the beer gods have not been kind to me this Summer. Or perhaps, they've just been too kind

Cheers,
Brian

[Fifer]

Right, an early unit - but an early kit one? Or stock?