Hello,

Suzuki are the only people essentially making a 750cc sports-bike these days ( it's been like this for a number of years too ), so it can be difficult at best to source reputable "hot-up" bits & pieces, as there really is no market out there for them, since they're their own class.

This is mainly due to Suzuki respecting the original GSXR-750 from 1985, & holding traditional values to it's original success, of light-weight, & big-power. Regretfully however, the International racing rules & classes have changed ( in part ) to suit European makers ( namely Ducati ) & favor the rules to suit their v-twin & it's capacities etc etc. Also, the fact that the World Superbike Championship started to allow Big-bore 4-cyl Japanese bikes ( de-tuned ) to race against the Ducati's, & the fact that the FIM World Grand Prix rules changed from 2-strokes ( of 500cc's ) to 4-strokes of large capacities ( just under 1,000cc's ), & the 750cc category disappeared....The 600cc sports-bikes proved a bigger market too, with much cheaper running costs etc etc.

Most Suzuki engines are provided with 3-differing piston over-sizes available, these being typically 0.5mm,1.0mm, & 1.5mm. You'll find some good mid-range power increases at the least by fitting the 1.5mm over-size pistons in there.

Your standard bore & stroke dimensions are 70mm x 48.7mm, giving you 749.678cc's. With the 1.5mm over-bore ( if available ), will stretch your capacity out to 782.151cc's.

Good luck, & I hope this helps a little,

Rastus

 

There are no Suzuki oversize pistons for that bike because the bores are not sleeved, they are nikasil, or hard chromed. There are few aftermarket pistons available, but I can't find any. The reason is probably cost. The bore and replating alone will run about 700 dollars, and a piston kit would be about the same if you could find one. As far as the stroke, it would be possible, but crank mods and rods will be about 3500, possibly more because it will all have to be special order, and special made. Your best and cheapest alternative is to sell the 750 and buy a 1000, or pick up a 1000 motor and a conversion kit to mount a 1000 into your chassis. There is a lot more available for the liter bike than the 750. 1200 is not a lot of cheese for after market parts.

If you still want to build the 750, a set of drop in cams will run you about 800 dollars, Yoshimura makes a thinner headgasket to raise compression, a Power Commander 5 is about 400, and aftermarket full system exhaust is about 1200, and all of that will need set up on a dyno for 300 to 500 dollars. A ported head can be from 800 to 1200, and a turbo will run about 5000 dollars. Without the turbo you will still not have the power of a good tuned 1000. It would only make sense if you are racing a 750 class.

Are you a drag racer, or a corner carver? If you like the twisties, spend your money on rider training and suspension. The slowest part on most sport bikes in that nut right behind the handlebars.

 

The slowest part on most sport bikes in that nut right behind the handlebars.

So true....lol. All good advice

 

Alot of great info. Makes sense about the market being niche for both of my bikes... a 636 and a 750. Not a drag racer. Wish I was a twistie carver, but I'm in Oklahoma.... temporarily. But Dallas won't be much better. Out of everyone in my town of 50k people, I seem to be the only one who cares about suspension, handling, turns and proud to show my 1mm chicken strips, which would be 0 if I had my RaceTech feont forks done correctly, which will be sent to thrm this Winter. It wallows with everything cranked up. It's the Showa Big Piston - Separate Function Fork, that really no other bike has, so I don't think RT got it right as I had to request a few extra parts that were missing.

Anyway, I just wanted the baddest 750 around, like I have the baddest and quickest 600cc class bike in town. It's the bike I'm putting my money into like suspension. It's reqlly the best 600cc - 750cc bike I've ever ridden. Stock geared 750's can't hang till I hit 150, but that's OK with me, I sometimes shift for a 7th gear at 165 with my -1/+2.

I've had a couple plans for this bike. Fix it up correctly with nothing special and sell it for my liter bike, do the same and detune it with FTECU so my wiman can finally have a supersport to ride as she has a Ninja 300 she's outgrown and wants to turn the 300 (with everything bolted on possible added to it [$2500]) into a dedicated track bike, turn the 750 into my dedicated track bike so I can keep my immaculate conditioned '14 636 with all the money in, it in the same condition by not laying it over on the track till I'm ready to get my next bike (my dream bike which is the literbike I just referred to) or just make it into a flat out monster, hence this post of me exploring my options. Tracks here are more technical, not fast. 1000's are honestly a bit much for Hallett Dpeedway in Jennings, OK. You can YouTube it and see that top speeds don't go much higher than 140'ish

My plan has always been to get a 2017 Aprilia RSV4 RF with its insane sounding and performing 201hp motor, make it my dedicated street bike and turn the 636 into my dedicated track bike. I just love how smooth the 636 is, the ergonomics, how it turns in, handles (suspension is actually quite nice once I put better quality RaceTech springs in that have the same spring rate as stock), controllable, predictable, reliable, etc...

I've also wanted to build a bike collection too, but each bike being different than the same bike you'd see around town, except the RSV4. That bike will pretty much remain untouched minus exhaust and other small tidbits.

So other than a regular rebuild I can do plus adding cams and another internal part, thats about it. Already has a Power Commander 5. But I think with this mileage, I just need to get it running right and either sell it, let my woman learn on it and/or be my track bike to fudge up after I still get it running right. Lay it over.... whooptie doo

Sorry for any typos. The new Samsung S7 is great, but it's Auto-correct is nothing like the S4, S5 or S6 I had. It's retarded.
Thanks guys!