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Oilyspanner

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About Oilyspanner

  • Birthday June 30

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  1. Sorry for the delay, I've been fiddling about on another little project. My k and n was fitted when I bought the bike and a previous owner had hacked around the inlet with a knife !! I trimmed a yoghurt pot and siliconed it in the inlet, this gave a 50mm orifice and a radius going into it. It sounds like you may need to go up a size on the pilots, but if the idle and gentle cruise are okay, leave it until you have enough time to remove the carbs again - it's a bit of a pain removing them with the airbox. If you can find a decent setting with DJ needles and std e.tubes don't question it ! Dj needles have a different taper to the std needles, so probably will go rich quickly. Go with what the engine likes, I wasted a fair bit of time over thinking the jetting. Also make sure the engine is fully up to temperature when settling on the jetting, several times I thought I'd sorted everything and then went on a long ride and my 'wonderful ' carburation... wasn't so great.
  2. most of your running will be on the needles, if you've got a stable tickover and a half decent needle position you can ride it and figure out if any of the circuits need to be leaner or richer. I take it the dynojet kit came with needs and emulsion tubes ? if you use their needles, you have to use their emulsion tubes and vice versa, else it's near impossible to tune. Altering needle position is pretty easy, try a notch higher and lower, the engine should like one or the other more. Early in my ownership I had a k and N in the airbox and an Akra - I used 130 mains, std needles lifted 1 notch and pilot mixture screws out an extra half a turn..... obviously you have a DJ kit so sizes will be different, but the process will be similar. The good thing about using an Akra is that you know they're developed to deliver a smooth delivery, so that's one known, it won't be at fault. Does the bike run okay at any revs and throttle ?
  3. I'm well in my 50s and still a hooligan at heart, more considerate these days, but my bike is a bad influence
  4. An oil cooled engine won't pull 10800 in top.....unless it's very low, they drop away after 10k. The point of mph/1000 revs is that you can work out what would work for your engine, where the torque is, revs at cruise speeds etc. Our engines are vibey around 5,500 rpm, so it's good to avoid that. A 16 mph per 1000 top gear gives 80 mph at 5000 revs - relatively relaxed and away from the worst of the buzz. Road gearing is a compromise and depends what you want, acceleration, or more relaxed cruising.
  5. Just got back from helping my elderly parents. I've just realised that the primary drive will be the same, not changed to 750r - this would make more sense .... 1.565:1 not 1.74:1 15:48 gives, 6th 148mph 1st 58mph at 10800 revs But Joseph's 16 : 43 looks really good 1st 6.44 mph/1000 revs 69.6mph 6th 16.31 mph/1000revs 176.24 mph at 10,800 revs
  6. Forgot to add, definitely don't use 14/48 !!!!!
  7. Have just done some calculator work, using Joseph's ratios and a tyre circumference of 79 inches. 16:43 final drive gives 1st gear 5.8 mph/1000 rev = 62.64 at 10,800 revs 6th gear 14.68 mph/1000 = 158.54 at 10,800. The speedo would read more than this. Std 1127r 5th gear is 16.15 mph/1000 revs by comparison. If you can fit a 17t front sprocket with a 43 rear = 6th 15.59 mph/1000 & 168 mph 1st = 6.15 mph/1000 & 66.51 at rev limiter It's not worth doing the other ratios as they'll be closer than the std box anyway. Depends what you want ?
  8. As sago has said - you need to work out at what throttle. Here's what I did to know which percent of opening I was using, I rubbed some of the markings off while testing, but you get the idea.
  9. Makes sense, standard parts are expensive, not renewing them goes some way to paying for the rs carbs. The rs36 carbs are easier to set up and parts are readily available
  10. Oilyspanner

    Bst40's

    I've spent several years peeing around with the needles, worn needle jets/emulsion tubes etc. My findings back up what G1460 said. You need spacers that hold the needles central and within spec carb slide guides, mine were worn, too much slop and the needle will be moving all over the place, causing wear and incorrect fuel monitoring. You'll notice a 0.05 mm difference on the needle/needle jet orifice gap.
  11. If you can see that the emulsion tubes are oval, they'll be pretty far gone. You can drop the needles down to offset the richness caused - I've done this a couple of times, even gone down a pilot jet size because it caused problems there too.
  12. A bit late on this one.....did some thinking on this one a while ago : particularly on a faired bike, at speed you have high pressure on forward facing surfaces, but down the sides there's a drop in pressure. At high speed the engine requires large amounts of air, which further lowers the pressure within the bodywork..this would muck up fuelling that seems fine on a static dyno, so any air that can be fed from the high pressure area towards the air intake is a good thing..it lessens the potential losses at high speeds. Engines don't drag air in, they lower the pressure within them and it's the far higher surrounding pressure that rushes in to balance the pressure imbalance...if the surrounding air pressure is lowered, engine efficiency drops too.....so the tubes do help !
  13. The info is already in this thread - but one thing that's wrong is that 40c0 is gsxr1100 k and l, 41c0 is 1100m and n models - usa m and n used the earlier 40c0 inlet manifolds, as they kept the 36mm bst carbs instead of using the 40mm bst carbs like the rest of the world market. The dot heads used different shaped inlet manifolds, so ones from other models don't line up so well..at least as standard.
  14. I've got an old GS650GT whose inlet manifolds are hard, I'm going to soak them in an oil of wintergreen (methyl salicylate)/ isopropyl alcohol mix for a couple of days - this rejuvenates the rubber, it's been used by some people I trust, so should work fine. My 1100N's carbs have been off so many times the rubber hasn't had chance to think about toughening up ! I often put a thin layer of rubber grease on the rubber, this may help stop the aging process a bit.
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