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1988 and '89 GSXR750s and 1989 - 1997 short stroke 750 tea pots (although cams are softer profile)

Keep us up to date with your findings Dupersunc - good thread, I think there's a few of us who have thought about a 6 speed box, or closer spaced ratios - not because the engine can't pull widely spaced ratios, just that closer spacing doesn't upset the bike as much when cracking on a bit !

Not sure it's needed dude - mind you I fitted expensive iridium spark plugs which aren't really needed either ! - last for a long time though and don't foul easily. We all buy stuff for our bikes that isn't really required though. Auto oil stays in the engine for 10 -20k miles, my bike gets the oil and filter changed every 2000 miles (too early really) - a larger filter wouldn't be needed. Oil goes out of spec. with use, which would be hard on highly tuned bike engines, but it gets changed frequently on bikes. Once a bike engine is broken-in there's very little debris - some clutch dust and carbon, if you change oil/filter regularly 2 - 4k miles, I don't think there's anything to be gained. I use Suzuki or Hi-flow filters, not that Suzuki make the oil filters........ on old and newer bikes, never a problem with wear. There's no problem with standard filters or good after market ones as G1460 says, marketing men for products might claim otherwise.

What bike have you got ? Have you upped your compression, or advanced your ignition timing ? - hasn't been hot for a while, would've been water cooled today !

Jonny1bump's design - works a treat - anyone who has BST36/38/40ss carbs needs these spacers, if there's someone out there who could make them (easy enough with the right equipment), I reckon many owners would want them. They're fiddly to make yourself.

You're lucky being in the U.S. - Factorypro make a jet kit for 38mm carbs being fitted to the 1127 GSXR (the extra capacity doesn't require much of a change in jetting normally) - they cost us Brits and Europeans a lot to bring over here, but they're the best jet kits I've found and they use Mikuni jets. The altitude isn't too much of an issue, but combined with the high temperatures then oxygen will be more scarce, so will need to go down a size or two on the mains and lower the needle a notch and go from there. If you google it, you can find jetting charts for elevation - don't remember seeing one for temp though. Best to jet for the altitude you normally ride in - oddly, because you normally have high temps at 1000ft, yes the air will get thinner as you go into the mountains, but the temp will drop by several degrees with every 1000ft of extra altitude which helps a little - atmosphere will still be thinner/cause rich running though ! Changes to air filtration, exhaust, cams and big valves will have pretty individual carb set-up, some time on a dyno really helps here - seems a nasty extra expense, but can save you days of fiddling around with your carbs(and still not being happy). Good luck with your project.

The only thing that the heavy brace/bracket seems to really do is deflect stones from the chrome sliders. I made some plastic sections that did this job and fitted spacers in the mudguard mounting holes - 1 1/4 lb saved from the rusty thing being removed. The 750K9 front mudguard, on the 750 front-end I fitted, doesn't have a pig iron brace ! I think I drilled the heads of the small screws, then used pliers to remove the rest from the brace. The brace sits very unloved in a big box of stuff I've taken off, or have replaced with ally stuff instead.

Good you found the problem. Was jetted too rich - maybe best to fit a good after-market filter and maybe jet down at some stage ? - no air filter will make the engine wear quickly.

Doesn't sound like ignition from what you say, so carbs it probably is ...... Are all jet sizes on your carbs much the same as a GSXR1100K/L ? - this should be fairly close, enough to run well enough to adjust if needed anyway. If you're using GSXR750 carbs and the needle from that, the 1127 engine may need a richer needle. Is the float height set correctly on all carbs ? - this can affect all circuits. When ridden and it halts at 5k revs, does it buck around like it's running out of fuel, or fall flat on it's face ? - lean or rich - from this you can work out what to do.

G1460 has answered pretty much everything - you'll need to budget for new oil seals for the head and oil drain tubes at the front of the block - it's easy to put it all back together and see oil happily p-issing out on starting ! Without some flowing work the larger engine will produce it's power lower down the rev range - big bores effectively reduce the tuned state of an engine, if everything else remains the same - in our engines they will produce a lot more torque. If you have the inlets slightly reshaped and the exhaust ports polished, you can gain 5 -10 hp by making the head more efficient - the power will climb on from the power curve of just a big bore. The only reason 1100 Ks were more powerful than the OC models after it was the silencers, the L,M and N all had an extra baffle plate in them that reduced max power for the 125 hp limit of the time (they normally made about 117hp with these silencers), cocked up the power curve lower down too !

Thank fook for that Swiss ! I was thinking - I don't remember the Bandit flange being an inch thick !!

GSXR1100 ones are M8 x 25mm standard - should be the same

Bloody hell Swirl, I bet that made your eyes water ! - rather a petite young lady fell in my lap........ Good old oc unit though, what's the plan ?

Good bit of lateral thinking RP -not heard of this mod before - reckon you'd need a lot of dry builds and measuring to make SV pistons work, sounds like they're a chunk heavier too, so would need stronger rods. 17g of piston weight saving is a lot, you can notice a wheel that's 15g out pf balance, a piston has to rev quicker than a wheel and go from full speed to a dead stop and back again - even a couple of grams is a lot for a piston/valve. Working out comp. ratios can be difficult, as how 'lumpy' the crown is makes a big difference and where you might have piston to valve welcome parties ! - plastigauge and burette would sort out many of the questions/problems.

A caged Tiger (stripe) !

As above - + nothing really different between K and L cams - power difference was more restrictive silencers on the L, put a full system on either and they'll make the same power. Slabby cams are within a gnats todger too !

The small single k and type filters can restricted air flow at higher revs (especially tuned motors), causing a rich mixture/reducing power - the dual filters are much freer flowing, only one of the linked carbs is drawing air at any one time, so there's a much larger filter area for each carb - they lways need jetting up. Have found missing horses by swapping to dual filters before. If just sorting single filters, down-sizing mains should work as per Rossco.

I converted mine 2 years ago, works really well and tidies up the area above the cam cover. Use the GSXR750 Y - K5, 600 K1 - K5, 1000K1 - K8 coils, GSR600 coils are fine too (GSXR600K4/5 engine used). There are other coils that have the correct impedance and length too, but I don't know them well enough. You've got to watch out for failing used coils (they often test okay), often a poor idle or off idle problem in the early stages, at least if you swap them round you can see the problem moves with the coil - by sooted spark plugs/cooler downpipe. Used stick coils are cheap though. With stick coils you don't get HT lead problems, cos there aren't any ! - all low tension wires above the engine, less chance of shorting.

I didn't post a recent photo of mine, here's one with the GSXR750K9 front-end, a further 8lb knocked off of the slightly lightened original set-up that was on it - looks alright. The foxeye fireblade headlight isn't as good as I'd like - I'll probably have another go at reshaping it in the future.

Liking the colour scheme Del, sort of a variation on a Suzuki scheme - nice !

I reckon the U.S. were the lucky ones Boilerdude, an extra year of OC 750s ! - I could have a 750N with the black/silver tiger stripe design to go with my 1100...... It's odd that Suzuki didn't release OC 750s in every market in 1992, the 1991 M was loved by the press and public - pressure for water cooled engines for racing perhaps ?

As RichyR says - if the float valves can't close off the fuel you'll get bad running on the affected cylinders (flooding). Even a bit of crud will stop the f.valve from shutting off. The plugs might be shorting due to being fouled. It'll be something small and annoying !

Needles don't really come into play at starting speeds - plugs (HT leads), float height and pilots are normally the culprits - needles need more revs/vacuum to lift the needles on cv carbs. From your other post at least it's not a coil issue, as it's 1 & 2 that's the problem - worth checking the leads connection to the plug caps Mr Blue, as with all these starting/tick-over type problems it's likely to be a small fault. Probably teaching you to suck eggs, but it's just a case of slowly working through each section that's involved.

Wish I could do some weeding and find a Slingy frame Viz ! - normally just find dandelions and maybe one of the dog's old toys - it's not the same.......

It sounds like the Triumph linkage and ratio is different to our Suzuki's, working on a smaller stroke (although wheel travel is much the same), much harder spring - this means the shock will work over a decreased stroke and with much stiffer damping rates. Much better to buy a shock that has stroke/spring rate and damping rates already sorted for the bike. As DuperS says - getting the suspension sorted is vital and the best investment you can make. The British made Nitron shocks, even the basic one, are brilliant units - shame they seem to be £80 or so more expensive than when I bought mine, not a bad price for the quality though.