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Discussion Starter · #1 ·
\'89 750 RRK Data

While we're waiting for someone to give me permission to post it to the specification section I'll post it here.

Four-cylinder, four-stroke, air/oil cooled with SACS, DOHC, TSCC, four valves per cylinder.

bore/stroke 70mm x 48.7mm
cubic capacity 749cc
compression ratio 10.9:1
carbs 4 mikuni 40mm slingshot
ignition transistorized
starter system electric
lubrication system wet sump
clutch wet, multi-plate type
gearbox six-speed, constant mesh, close ratio
front suspension 43mm telescopic, spring preload, fully adjustable
rear suspension Full Floater, spring preload, fully adjustable four way rebound damping adjust
front brake twin 310mm disc, nissin four-piston calipers
rear brake single 200mm disc
front tire 120/70VR-17 v250
rear tire 160/60VR-17 v250

overall length 81.1"/2060mm
overall width 28.7"/730mm
overall height 44.5"/1130mm
wheelbase 55.5"/120mm
ground clearance 4.7"/120mm
seat height 31.3"/795mm
dry weight 411#/187kg

What was changed? Plenty. The top rear shock mount was lowered 4mm. The fork tubes were lengthened 6mm. the fairing lowers were recontoured to give better clearance. THe intake ports were reshaped. 10mm racing spark plugs. Racing valves and springs, a stronger crank, stronger rods, and a magnesium valve cover found their way to the motor. The main oil cooler was enlarged and there was a second cooler mounted low in the fairing. The crankcases, crankcase covers, were chamfered to improve cornering clearance. The exhaust was a stainless steel 4-into-1 with an aluminum muffler. The bodywork was fiberglass with quick fasteners. The fuel tank was aluminum. The rear wheel was 5.50 x 17".

An additional motor kit was available from Suzuki. It included forged pistons with high compression ratio, different cams, racing exhaust, different transmission gears to vary ratios, countershaft sprockets, spark plugs, dry clutch kit, racing cam-chain tensioner, black box ignition, starter motor, alternator plugs and a larger sub oil cooler.

A chassis kit included rear sprockets, adjustable swing-arm struts to change ride height, racing forks, racing rear shock, racing steering damper, racing wiring harness including a kill switch and a small battery.

All this info is from the book SUZUKI GSX-R750 by Gary Pinchin and can be bought from amazon.com. It's where I got my copy. It's a really good read.
 

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Re: \'89 750 RRK Data

The RR sounds like a very impressive bike for it's time. I have to wonder why suzuki doesn't do more limited bikes like that.
 

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Re: \'89 750 RRK Data

my guess is that they produced the rrk out of necessity......superbike rules don't allow you to change the bore and stroke of the production motor. since suzuki discovered that the short stroke motor was pretty problematic in superbike tune, they needed to rehomologate the long stroke motor quickly to be competitive again, so they made a limited run of rrk's. a year later the long stroke motor made it into the regular 750's.


bcklrcr,

did the book mention why the rrk was produced?

didn't know the bodywork was fiberglass, pretty neat.
 

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Re: \'89 750 RRK Data

I quote..."Suzuki continued to develope the GSX-R750 with a sporting application in mind. Race tuners found it difficult to extract winning horsepower cout of the '88 and '89 short stroke engines, so for '90 Suzuki's engineers reverted to a longer stoke and smaller bore for the GSX-R750L."

It confirms what was said earlier, the short stoke motors weren't competitive. For '89 Suzuki made the required number of long stoke motors to meet homolgation requirements.

What's interesting is that the L model has many of the parts of the RRK model, but at half the price.
 

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Re: \'89 750 RRK Data

Yeah, that additional kit black box was the one I just got recently that made such nice bhp and torque gains on my '93 CDN 1100w. Who would have thought!

Apparently it retailed for something like $1000.00 when new...figures for the factory stuff.
 
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