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About Oilyspanner

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    Ball Peen Hammer
  • Birthday June 30

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    South of England

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  1. Oilyspanner

    1216 bandit with modded airbox

    An airbox does a number of jobs. Here's just a portion of them - The intake tract resonates due to the movement of the pistons and valves opening and closing (you are aware of this from the noise of open carbs) - the resonance can be used to aid flow, particularly at low/mid-range revs. The intake length has an impact on the resonance, so this can be used to boost various bits of the rev range - so helping overall power curve. There's a load of boring/interesting physics in play along the inlet tract, modern bikes make better of the airbox and intake system than our bikes, which were designed in the early days of airbox dynamics. A carb with a velocity stack will flow very well at high flow rates, but an engine with overlap will be boosted by the use of a tuned inlet length and airbox, not necessarily at peak, but it can be made to be a lot more effective throughout the rev range - as most bikes are ridden on the road and at a variety of throttle openings this is very helpful An airbox allows cooler, denser air to enter the carb, although it's only slightly helpful on most of our bikes - slingshots do try to vent some cool air to the rear of the airbox. An engine doesn't really 'draw' (as in suck) in air, the piston's downward movement causes a lowering of pressure within the cylinder and it's the higher atmospheric pressure that 'pushes' air through the carb and inlet , to cylinder- the velocity of air causes a lowering of pressure, which enables the carb to force fuel/fuel vapour through the jets, because the float bowl is at atmospheric pressure . I don't pretend to know everything, but I've tried to learn as much as I could over the years on how carbs work. I promise not to talk any more on this subject...….but some info into why airboxes can and do help seem to be needed.
  2. Oilyspanner

    Inlet rubbers

    Mine are like yours Blue - 1991/92 shim head 1100 inlet rubbers, for use with 40mm carbs. Numbered as you've said.
  3. Oilyspanner

    GSXR1100M Engine into Blandit

    As Rene - a fresh engine with good piston ring sealing, good sealing valves etc should be good for around 140 hp, a used engine with unknown history ? something less than that.. do the valve clearances, people often don't like doing the shim heads as often, it's easier to do the screw and lock nut ones. If it's a good engine you should be pleased with the result, especially the second half of the rev range... good luck - Oily
  4. Oilyspanner

    Gsx1400 zorst on oil cooled

    Pretty sure B12 headers flow better than the 1400 - you can fit what cans you like on the 1400 headers and you don't gain much, the same can't be said of the 1156. They're very restrictive and some of the heaviest pipes going, makes the 1100 Slingshot std system feel light ! - the double walled, chromed pipes do look nice on the big retro though.
  5. Oilyspanner

    another jetting thread and cam timing

    You're doing the right checks - if you know someone with a GSX1100F/GSXR1100 see if you can try their ignitor box - a ride will confirm if your box is restricted/faulty etc - the appearance of the missing 40% should be easily felt !! Oily
  6. Oilyspanner

    another jetting thread and cam timing

    Have you had this engine running strongly before VJ ? or has the power only been less than great after this rebuild ? - I remember you had a piston/valve coming together on first build, did you use a GSX750F head on this or the 1100G one ? - trying to spot something for you … it's great when all works a treat but an utter pain in the arse when your hard work seems for nowt. My last big project was fitting a big bore kit, flowing the head and setting the cams etc - one problem I did find was that when I tightened the cam sprocket bolts, the sprocket moved - caused about 3 degrees of error - had to do them twice.
  7. Oilyspanner

    another jetting thread and cam timing

    It's peaking early. but doesn't fall away completely after... what ignitor box are you using ? - although power peaks early it's revving to just over 11k - GSXR1127s hit the rev limiter at around 10,800 (true revs) ….. dunno what's happening. What's your exhaust like ? - even a poor design shouldn't kill the output that much . It's not like your bike is making loads of bottom end and losing at the top …. it looks like a 750 Inazuma dyno run, or Swiss market bike - it does look like one or two things are restricting it VJ.
  8. Oilyspanner

    What’s wrong with my bike?

    I can see the Mikuni marking on the needles Kurf, but they're a sharper shape (richer initially) than my FactoryPro stage 3 ones. 150 mj should be close. You should get close using these guidelines from FactoryPro http://www.factorypro.com/tech/tech_tuning_procedures/tuning_carbtune,CV,lower_rpm_engines.html
  9. Oilyspanner

    What’s wrong with my bike?

    Need more info Dude. What air filter/filters, are the float heights accurately set ? It sounds like it's running very rich - are plugs sooty ?. Are the main jets Dynojet ? - they are different to Mikuni. Before you go to the dyno, make sure the float heights are set correctly - when the fuel level is wrong it will muck up most of the carb circuits and give you endless problems to get the bike running well.
  10. Oilyspanner

    Slotting sprockets

    Glad you found out why the pistons met the valves first time round VJ. For more torque and better bottom end go for smaller numbers and for top end go for more retarded settings - larger numbers. Standard cams are better when they are close to recommended figures - I had a little play with settings recently and going more than a degree or two away from std wasn't great, too retarded was worse than advanced, at least with advanced you have loads of drive in the first half of delivery.
  11. Oilyspanner

    BST38 help!

    Has to be rubbish on valve seat or worn needle, really takes very little..... damn annoying, at least you know it's on #3 carb - good luck !
  12. Oilyspanner

    Adding some torgue and bhp

    Unless your fuelling is off, you won't gain a great deal with a jetting kit - you've got a nice smooth curve, so it's not far off. If you want power and torque, fit a big bore kit and fit GSXR cams, 1100 cams will work well - this isn't hard on the engine as it's a detuned GSXR1100 engine to start off with, with loads of scope for reliable power gains. With these mods you'll need to alter the jetting , but you'll have a much more potent motor at the end of it , from low down to high up the rev range. If you do these mods you'll be very pleased with the results - Mr Viz the moderator/judge/executioner/cartoonist extraordinaire will be happier too !
  13. Oilyspanner

    1990 gsxr750m

    One thing I did find about the weight figures between the 750 and 1100 L models and M models is that Suzuki seemed to have changed their claimed figures (more truthful). The only heavier bits of note on either are the glassed in headlights, all the main bits are very much the same - a few years ago I looked up the real weights from magazines that actually weigh their test bikes, not use claimed figures (10/11kg difference in claimed figures) - both 'M' bikes are within 2kg of the 'L' and if you weigh the headlight bracket and headlights of both, the difference is almost all their. The worse thing about the glassed in heavy headlights of the late 750 and 1100's is that is a bad place to add extra weight, it's a long way from the centre of mass and high up, so has a greater effect - add 2kg just above the engine and you won't notice it, put it at either end and high up - you certainly will ! I made an aluminium headlight bracket and made a 'foxeye' fireplace headlight fit, it saved just over 6lbs, nearly 3kgs, it made the bike feel like it was running with an empty fuel tank in comparison. Sorry for going off the subject a little, thought it was interesting though - the pretty faired in lights of the last 750/1100 bikes weren't great for handling.
  14. Oilyspanner

    1990 gsxr750m

    Looks like the fork sliders are corroded, the other bits can be done along the way - the great thing about the 750 L/M's is that you can slot in more recent forks, 50mm and 54mm at the clamps - big choice compared with 1100's. Old alarms and immobilisers are a complete pain, extra stuff to go wrong.... always seem to corrode at the joins and terminals - well and truly immobilised !
  15. Oilyspanner

    1990 gsxr750m

    Don't break it MartynGSXR, I'll buy it and get it working properly - I've always liked those colours, as long as the engine isn't seized...... move it on and make a bob ?