Z750R Engine Mods

[Coby]

Hi All,

I've got a Z750R, really nice bike, had it since new, took my time running it in, always had fresh oil, I can't remember ever even redlining her, so the engine is 'sweet'.
Looks good to; satin black, belly pan, Kawasaki engine protectors, tail tidy, little tinted Puig screen, hugger, rad. guard, Acro 'silencer'.

But now that she's done 20 000 miles I have to admit that I've always had a sneaking desire to doing something with the engine, thing is I'm not sure what would make a nice difference without making her unreliable.

Is an ECU flash of much benefit?
Anyone know where I might be able to get her bored out to say, 800/820cc perhaps?

Losing one tooth off the front sprocket, fitting the Acro and running her on 97octane gas makes her take off at an impressive rate already, no wheelies, no wheel-spin, just pure forward motion!

Not being that tall at 5'8" I don't weigh too much, so moving up to a 1000cc machine might be a bit much, also the 750 is good in the 'flip flops' having a heavy crank but a relatively light top end.
So I'm into the 750, just wondered how easy it would be to get a little bit more out of her.

[redeem ouzzer]

If you’ve never redlined it you’re not braying it enough. Rev it till it stops. It can take it.
____________________
Be a REAL MAN!

[Coby]

I've had it since new, I didn't want to hurt it!

Yet.

[Coby]

There's a thread about ECU flashing, I've just been reading it.

Apparently there's a guy called Mike who's worth talking to at Velox Racing, I think I'll e-mail him next week.

Anyone got any ideas on a big bore?

[P.]

[Nobby the Bastard]

My litre sprint gets red.lined.

It's done 35k.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Easy-X]

[Coby]

I reckon the 1000 is a bit too big for me.

I could have got the 1000 when I bought the 750, one of the regulars at M&P even offered me a swap.
But when they were both side by side in the showroom, the extra weight of the 1000 put me off, it felt kinda 'top heavy' compared to the 750.

But you know what its' like, what ever you've got you're always wondering whether you can get just a little bit more out of it.

There's something else:
Once you've gone past peak power in one gear any engine will effectively accelerate faster in the next gear, so for the best performance you should drop just short of or perhaps 'kiss' the red-line, which I do do frequently!

[Coby]

Oh Easy,

How much would I love that!

unfortunately osteo-arthritis from the base of my spine to my toes means I can only sit upright.

[Easy-X]

[Coby]

[MarJay]

Umm... I can't believe I'm the first to point this out but...

What is the freaking point of tuning if you don't even thrash the nuts off of the bike in the first place?

I've read a few articles in bike magazines that show how much throttle the average person uses, and then before being told their actual figures the riders had to estimate it. Most said they were on wide open throttle maybe 30% of the time. In reality it's closer to 1 or 2% with only an ex racer getting to 10%. Many of the ordinary guys weren't ever fully opening their throttle.

So, on that basis, if you've never redlined your bike, it's a total waste of time and money tuning it, as you'll probably still ride at the same speed just using even less throttle and even less revs.

Japanese engines have effectively been idiot proof for about 30 years or more, particularly the 4 cylinders. Hammer it. Rev it to death. I guarantee your shock, suspension bushes, linkages, brakes etc will die a death far before the engine does. Change the oil and other service items on schedule, and twist the throttle.

if you DO want to make a mod, drop a tooth on the front sprocket (put a smaller sprocket on - don't do what some dolt on facebook did and grind off a tooth!) and revel in the new acceleration. A bore kit? Nah, you'll lose money. The bike will become less valuable because it's been messed with. Mint original bikes retain their value. Tuned ones don't.

I also have a theory that there is no point tuning a bike that isn't the top spec of that type of bike. Tuning an 800 is pointless when you can trade it in for a 1000.

If you ignore what I'm saying, you might as well just take your $ and throw them into a dumpster for all the good it will do. Spend the money on suspension improvements sure. Spend it on rider training. Don't tune a reliable engine, especially where you don't already use it's whole potential.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Coby]

Hi Marjay,

There's a big difference between 'kissing' the red line and just revving into the red line and holding it there. As I explained earlier, you don't gain anything from holding an engine in the red line as you've past peak power; therefore you may as well change up.

I agree tuning a bike may make it less reliable and decrease re-sale value, but I've had the bike since new and I like it very much, but now it's done 20 000 miles I would be interested to see if I could give it a little more oomph.

I already changed the front sprocket to give myself more acceleration and also run it on 97octane gas, therefore it's very quick; but could it be quicker?

The 1000 is too top heavy I reckon, not so good in the 'flip flops'!

[Old Git Racing]

The engines in jap bikes are pretty tuned anyway. Maybe a power commander and dyno time to set up the fuelling would get most out of it whilst keeping it reliable.
Losing weight, especially unsprung is another way, how about carbon wheels and some titanium bits, would look cool as well.
My mate I raced with had a head job, cams, full race system,dyno, cost him loadsa cash for an extra 15bhp, on an R1, so I imagine the gains would be less on yours.
There will be loads of tuners who can do it, the basic principles apply to all engines, only you can judge if the outlay involved is worth the modest gains you will get
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2022 Tiger Sport 660 2019 Street Twin 2003 K3 gixxer 1000 1998 Srad 600 track hack

[Nobby the Bastard]

[redeem ouzzer]

Get it turboised.
____________________
Be a REAL MAN!

[Coby]

[Irezumi]

Have you considered the newer Kawasaki Z900?

[Coby]

yeah, I have to admit I have that Z900 is a nice looking bike.
I think they're offering test rides in Frazers.

[Coby]

Having said that, riding my Z125 all week when I get back on the Z750, it does feel incredibly fast especially since I've been running it on 97octane gas (it takes 3 or 4 tank fulls before it makes any difference and seems to be ambient air temperature dependent ).

[Coby]

What the fuck!

When did I become a Renault 5 driver?

[Coby]

This is my car:

[Coby]

Now I've learned how to do it, here's a pic. of my bikes as well:

[Coby]

Would that be a 'vauxhall Nova'?

[trevor saxe-coburg-gotha]

trade the 125 in for a strimmer
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"Life is a sexually transmitted disease and the mortality rate is one hundred percent."

Mobylette Type 50 ---> Raleigh Grifter ---> Neval Minsk 125