zxr 750 j1 premature limiter

[j4m13]

Hi. I have recently bought a zxr 750. It is a j1 and is a jap import. Bike revs right to the top in neutral or in gear with the clutch in. However when out on the road every gear seems to hit what feels like a limiter at 8.5 k this equates to 110mph in top gear. Is this a jap restriction. If so how do I get rid of this.

[RhynoCZ]

What's your final drive gear ratio?
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[j4m13]

Std. Does it in every gear though.

[RhynoCZ]

I doubt there's an electronic device that'd restrict the engine when at speed. I'd check the ram air intake system, airbox and carburetors for any restrictive stuff. If there'll be nothing, then I'd check the jets.

I can't really think of anything else. There must be some restriction in the intake/fuel system. It could also be ignition.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[Coxyzxr]

Check all airbox hoses and areas.

Revving to limiter at standstill but not under load sounds like a fueling ratio issue.

If there was a limiter it would normally be limited in neutral and/or clutch in too on older bikes. Zxrs do not have sophisticated electronics, no gear position sensors or maps for certain gears etc.
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**WAS FITTED "WRONG WAY ROUND" !** CANT ACCOUNT FOR THE STUPID !

[j4m13]

Cheers boys. Will investigate at the w/e as I said though cuts out bang on 8k in every gear but revs right out in neutral and clutch in.

[Hugh Farking Cant]

Jap home market bikes of that era were limited to circa 112mph by the CDI. (unsure if TCI or CDI on 750 J ).

Restricted smaller Yamahas of that time limit rpm to 12,500K in all gears if tampered with. The Kwak may be similar.

It does seem ignition related if in all gears.( especially as you state ;
"bang on 8K")
The ZXR400 imports had a limiter, a small sealed box in the region of the speedo .

Has it still got import speedo fitted or been replaced by a mph unit ?

There is a zxr 400 specialised forum; it may be prudent to join simply to pick the bones out of any derestriction threads on there ( must be loads)

The J series has no ram air induction as suggested in earlier posts.
The hoover pipes are cosmetic and blanked at the tank.
Ram air started on the L models.

Look on the ignition unit (CDI/TCI) to see if any numbers are visible still; they are printed and have a tendency to wear off though.
Compare to pics showing numbers on Euro ignitors.

The 900 unit fits the harness but has a lower rev limit, (recommended to swap if engine has been upgraded) so other units do fit and run with that harness.

ADDITION; restricted Yams will rev out;off the clock, whilst stationary but not whilst in gear/ moving ; Kwaks MAY be similar.
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