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Posts posted by Oilyspanner

  1. 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.



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  2. 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.

  3. 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. 

  4. 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 !

  5. 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.

  6. 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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  7. The 1990 and 1991 750s have an extra row compared to the 1100s - the taller 1100 engine doesn't have as much space above the headers because of it's longer stroke. This also tells us the frames of those years are the same size.

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  8. There's several types of Nitron, the ntr1 doesn't have a remote res. It works really well, I had that one first. I've  since bought their fancy race one,  that has a fixed reservoir - it came up second-hand , it had been on a race gsxr600L4 - I had to swap the bottom link to the clevis type link - this is why I know about the 600/750 shocks _ the spring rate is suitable too.

    The 1000k5 is very long as I remember, 330mm or more I think, I'm sure there's a swaps thread in the vault maybe ? You can make shocks  fit with different length linkage rods/dog bones, but if you go too far the main linkage angle changes, so the shock doesn't  work as well. Anything works better than a shock with no damping though.

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  9. Something I did to quickly work out true speed in each gear  _ this is for gsxr1100 k-n and b1200

    Quick calculation helper numbers.

    1st gear  0.25381

    2nd gear 0.37099

    3rd gear 0.4841

    4th gear 0.58182

    5th gear 0.66275

    Then measure rear wheel circumference in inches - you multiply with this number.

     work out final gear ratio, you divide the number by this. This give mph per 1000 rpm.

    Often used final gears and ratios

    14 : 48 = 3.43

    15 : 48 = 3.2

    15 : 47 = 3.1333

    15 : 46 = 3.0667

    15 : 45 = 3

    Here's 4th gear speed for my bike for example.

    0.58182 ÷ 3.0667 × 79.5 inches = 15.08 mph per 1000 revs

    For 5th

    0.66275 ÷ 3.0667 × 79.5 = 17.18 mph per 1000 rpm


    All I did was work out most of the calculation minus final drive and tyre circumference , I just like working things out .... hopefully someone will find it useful too.


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  10. I bought a Nitron shock for my 1100n, best thing I did early in my ownership of my bike - any decent shock will make a big difference.  The standard shock is only 312mm eye to eye, a bit longer is good - the gsxr600/750k6/7 shock is 320mm long , has good spring weight and the correct fitting at the bottom, the later shocks have an eye at the bottom link.

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  11. The angle of your swingarm looks greater than mine. I've got an 1100N, with gsxr750 k9 forks, 750L2 wheels and a Nitron race shock - I kept the std swingarm and linkage, so a few similar things. I've 12mm of static sag on the rear - the amount the shock compresses due to the bike's weight, if you have next to no static sag, ie the shock is near topped out all the time. Lift the rear of the bike at rest and there should be some movement until the shock is topped out. The shock has a 475lb spring on it now, the 500lb/inch spring only worked when I was really tramping on. The forks still have the std springs in them and have 30mm of sag, I think the 750k7 had .95kg springs in them, the 1100's were around .75kg, so plenty firm enough. My bike is 96lb lighter than it was and handles really well, feedback is great front and rear, they can handle really well. 

    I expect it's just in the set-up :)


  12. You'll have a power delivery full of holes, that was my experience trying to make my 40mm carbs work without the airbox - I used the std velocity stacks with ramair filters squeezed over the ends, I even had a factorypro kit for this conversion …. factorypro made the kit to work with k and N dual filters -  still think the airbox is needed, or some sort of airbox to make the 40s work well. I like a challenge and thought the weight saving doing away with the airbox would be a good idea … I failed. The bike needed 155 or 157.5 main jets to pull well up top - still not as good at any point as the airbox, pipercross filter, 145 mains, special needles and 40 pilots I have now - sorry sfc, it won't be easy. Flatslides are pretty easy to set-up for many altered filter/no filter stuff.     Oily

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  13. Welcome to the site. Just 4900 miles ? Probably  a typo. Have you looked at the plugs - a low speed running  problem will show on the plugs, normally sooty. You say you replaced all jets, does this include the needle jets ?

    Check your plugs to narrow down the problem, then you can move in the right direction.

  14. Got to add some fairly recent findings on this subject.

    I had my spacers  shaped like minipower's  (and variants of) before I bought Jon's spacers. I thought my needle jets were fine and initially my low/mid-range was rich with the new ally spacers - I milled .8mm off the spacers and got a good set-up ….. but this year whilst working on my needle tapers etc, it was obvious something wasn't right - turns out that 2 of the needle jets were pretty worn and the other 2 weren't in great shape. It's very easy to not notice the wear, they look fairly round, but they don't meter the fuel very well - especially if you increase inlet velocity with a big bore and flow work. Now with in spec needle jets, my own needles and Jon's spacers I have massive mid-range and perfect manners at idle and cruise. With standard spacers or modified ones, the needle jets will wear - I reckon my must've taken a few thousand miles before causing problems. The standard set-up is shite ! the needle either leans against the leading edge or wobbles about. 

    Looking back I should checked the needle jets more thoroughly - I wasted so much time chasing my tail !

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  15. On 7/11/2020 at 11:21 PM, Wee Man said:

    Cheers Oily. Colours not to different from yours, though it's often said the blue ones are faster....or was it the red ones? ;)

    Ah, that'll be the turboed  ones !   Maybe one day

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  16. It may be the clutch, but the purging of the fluid is a quick and easy thing to do - CliveGTO's  - gunked up inside the cover is another good one to check, nice and easy to resolve - if one of those works then happy days ! …… if not it will be time to open the clutch case and taking the clutch apart - even that's not too bad, just the clutch basket holding tool and the centre nut are tricky, the rest is easy enough - if it is the clutch, then at least the actuation side has been serviced !

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  17. The 1100F has a hydraulic clutch I think, it's worth bleeding some new dot 4/4.1 fluid through the system to remove any air/water in the fluid - the slave cylinder doesn't move the clutch rod that far, so anything that reduces the movement can cause the clutch not to disengage. Clutches tend to get grabby when hot to make things worse. Worth flushing the old fluid through before you go any further.

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  18. If the other electrics work  that are negatively linked to the engine/frame, then all should be good. I've had a couple of problems in the past that were caused by the low tension wires at the coil flag terminals fracturing - sometimes the spark was good and other times I had no spark when the wire moved, the plastic sheathing hid the break in the copper wires underneath - it might not be this, but worth a check. The wire on the flag terminals that attaches to the coils get twisted a lot when putting them on and off, causing fatigue/fracture. I checked for continuity by disconnecting the ignitor connector, linking each end with the multi tester and wiggling the wire - continuity kept disappearing - the break was just before the crimp. Hope you find the fault.

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