Oilyspanner

A mini moto is stacks lighter than a standard bike, specialised springs might be your only option.

The width in mm and length in cm are normally given eg on GSXR1100 86-88 page it has FRSP (front spring) S3234 = 32mm od and 340mm/34cm length. The original spring rate might be missing on older bikes though. The same period GSXR750 has a spring rate of .58 kg/mm - so it's likely the 1100 ran a slightly higher rate ( .68 ?) being heavier. Racetech are about the only people to openly print these details, been useful to me a few times.

Tyres and rims - always a good topic at the pub ! The race teams like to use the 6.25 rims for 200 tyres, in order to find slightly more grip at certain circuits, although the tyres will fit a 6 inch too - you just lose more stability and lose agility with wider tyres - a 200 on a 6 inch rim is okay, but not so great when a 5.5 rim with 180 is standard and works well, even at the track.. A 190 on a 6 inch rim can work well, just set your bike up to suit - in this case it just seems to be making more work for nothing. Wish I had a pint . . .

I was waiting for FBOB etc who've done a few of these to call by - but I'm pretty sure all the folks who've fitted dot heads continued to use 1100 or 1200 plugs - as CGTO. Running conditions are going to be very similar to the standard engine , slightly hotter because of the extra compression - but it's less than a point of compression (close to .5) and in a big bore going up 2 points you still normally use the standard grade plug . Good question though !

I'm pretty sure the early Suzuki stick coils and K series ones had the same resistance values, but the lengths vary - I stuck with the K ones because I knew they were the right length, were in spec etc - also they were newer.

Pretty sure you had dynojet needle jets and needles Nelson, so as Matt says, you'll obviously need Mikuni needles to suit - I expect your main jets are dynojet too, you can't use them either, they're calibrated on size of hole rather than flow rate like Mikuni ones. It's the reason I stumped up the cash to buy a Factorypro kit , they only use Mikuni jets, so you can buy spares etc - the critical piece of the kit is the jet needle, FP would've spent many, many hours selecting the correctly shaped needle, it's a much different taper to my standard 1100 one.

Mikuni mark their jets and have their Japanese character, the small square inside a square, stamped on most of them - Dynojet normally have dj on them. If the carb spacing is the same as your old carbs, the 38s have to be from 750 L or M - I can't remember if there is a lightly stamped number on the outside of the carb body on yours, if there is it will be as Cptn says. To get the most from your carbs, you'll need to match the diameters of the carb throat and inlet port - a 2mm ridge all the way round will cause a lot of turbulence and damage flow.

It looks like a jet kit - D or DJ then a number or two is Dynojet - Original Mikuni parts don't work with their stuff, it has to be one or the other. I've seen the oddly tapered needle before somewhere on the net. Best check all the jets for make and sizes.

Good honest old bike the Bandit, ride as is , mod it , nick the engine and put it in another frame - a lot to like, especially for £850 !

Check the condition of the earth lead and the heavy duty leads to and from the solenoid/relay (although you've mounted another solenoid/relay), plus connection of the feed on the starter itself - or as you point out the starter needs too much current (fooked). You can get all the bits to service the starter though, so even this might not be too bad.

'kin 'ell - now that's not a situation to be caught in, 140 mph, rear wheel covered in oil !!!!!!! - the worst I've had is riding on aging Avon 'skidmasters' when I was younger, the slowly deflating rear tyre wasn't as bad as them !

Hi G1460 - I followed the 'how to' guide in Practical Sportbikes. They linked each firing pair in series, with one coil feed wire going to the left connector of the left hand coil and the other feed going to the right hand connector of the right hand coil - the other two coil connectors are then linked. As I see it, coils don't mind their polarity and being linked there's a 12v feeding the circuit. I'm no great electrical guru and it took me a while staring at the PS article to convince me to do the work. The engine seems to have a really clean spark from tick-over to the rev limiter. Oily

Out of interest I measured the resistance through a pair of connectors going to a pair of coils on my cop converted bike, it was 2.5 ohms - which is fine for a Slingshot. I used early K series GSXR stick coils, more recent ones use low ohm coils. I've been very happy with the conversion, can't remember if I did it last year or the year before, really quick starting and very neat - no HT leads clogging up the space above the engine - saved 10oz too. Will let the board know if any problems occur, but the ecu should be happy with resistance value.

If you can find a kit, a 2mm bore increase will give 793cc -any for the long stroke 750s should be fine. It's a shame that the 73mm pistons from the short stroke 750s won't fit - gudgeon pin 2mm bigger, like 1100s.

Easy to put an 1127 or 1156 engine in there, it always costs a fair bit to buy the big bore kit, bore the liners and buy all the gaskets. GSX1100F engines can often be bought for decent money and they have far more 'go' than a big bored 750. Welcome to the site too - almost forgot !

C1 is definitely for the 40mm CVs, I had a slightly damaged carb top on one of my carbs - I noticed that the 36mm tops don't appear correct and I wasn't sure about the 38s, so I searched around on the net until I found the correct one at a decent price. I think the diameter is okay , but the central protrusion length varies. Someone has probably altered some or similar, so maybe they'll add to the thread . . hopefully !

That's a nice treat Hutch ! Some nice touches, colour matched forks, frame, swing-arm etc hmmm, always liked those 750Ms and that's a goodie.

The 750RK had the long stroke motor, but the frame was very similar to the J/K frame (same head angle), but with some strengthening around the headstock. From the time I seem to remember that the RK had a braced swing-arm 10mm longer than a 750L and ally tank 19L not 21L - the engine had a few differences, close ratio box, long stroke engine, 40mm carbs and it had higher spec suspension - I don't think the frame was very different though, don't think it even had swing-arm pivot height adjustment. There's not night and day between any of the Slingshot frames, but there can be with careful set-up and good components on any. The earlier frames (Slabbies) were lighter, especially the 750, but they are different to ride.

I didn't know it was your design I used for the needle spacers John - found the drawing of the spacer on some search I did, it works really well ! The standard spacer does hold the jet needle at an angle as you say, hence the uneven wear. I had a K n N in the airbox when I got my bike, it seemed okay, but the inlet aperture had been mucked around with, so I bought the big Pipercross filter - 3 inch inlet and a physically big filter, loads of surface area. I had enriched the carbs for the K n N and full system, but the bike was very lean after fitting the PiperX, the std needle size was too far off (even with extraspacers and clips on the bottom notch), so I bought the FactoryPro config3 kit - it made a big difference.

Just as FBOB says - I've got RF wheels on my 1100N, it's just the rear wheel that need slight attention. The straight spokes are lighter than the twisted spokes too.

Nice input J1B, I think the 40s are airbox sensitive. I've kept my airbox and fitted a Pipercross filter (big, free flowing filter), which flows so well I had to fit the stage 3 carb kit - works really well. Maybe if you're going to use pods 40s wouldn't be as good as smaller 38/36s . There was a thread on here recently about 1100/750 frame differences (there isn't much on Slingshots) - I was waiting for you to say that you got on well enough with the 1100 frame on track ! Have just spotted you did see the 750/1100 frame post . . . .

I bought a FactoryPro jetting kit which was very good and I dialled the settings in via FP's excellent 'how to' method http://www.factorypro.com/tech/tech_tuning_procedures/tuning_carbtune,CV,lower_rpm_engines.html The carbs feel so good I haven't bothered to run it on Dyno, all circuits seem to work well.

If the 40s are in good condition, they're a decent carb, if a bit harder to fine tune, but work well. Are your needle jets okay ? they have a tendency to 'oval' if you look down through them (all BST carbs) and the engine will run like sh-te. Oddly the M/Ns had a reputation for not liking the earlier K/L silencers and worked better with the 41C0 ones - just an example that perhaps the 40s are more easily upset. Mine work really well and I wouldn't swap them - smooth torque from tick-over and pulling strongly from 3000. They work very well with big bores.

From Cycle World 1988 - fully fuelled weight 491 lbs, wt distribution 48.9 : 51.1. As has been said, wt distribution is one of many factors that affect handling, but if the wt is in the ball park, then the front end should work. Give the forks a good service, they'll work a lot better - heck, they're 27/28 years old now !

Sounds like the battery is low on charge too, the solenoid clicking means there's not enough charge to engage starter. Low octane fuel can cause pre-detonation and excess heat. 11:1 comp. ratio isn't a problem - there's 1000's of oil cooled engines running well with 11:1 and 12:1, but you do need to put half decent fuel in your tank.. It takes a lot to kill one of our engines.