bluedog59

Spark eroding.

Do you have to use genuine head and base gaskets ? Some pattern ones are thinner than standard.

First rule of racing : Read the rule book, what it says and more importantly, what it doesn't say.

Maybe it's time to take the head off and sort it. If you're going to race it a little look round and tidy up will not go amiss anyway.

While I have zero experience of dynoing a turbo bike I have done 100's of runs developing my carbed race bikes and I believe the basics apply no matter what. Make sure the bike is up to it, Dyno runs are brutal. Check the chain/sprockets, rear tyre are in good condition and tensioned. Oil level is correct and take spare oil if you have to remove any covers for any adjustments. Check all oil cooler fitting are tight. Take spare plugs in case you need to change them. Take your own tools including any special ones required ( don't waste the Dyno operators time looking for tools to borrow). Make sure the kill switch works and is easy to operate. Check and double check everything is tight, safe and correctly routed. You're pay for the operators time and experience so make the most of it. Don't get hung up on the numbers, you're looking for power where you want it, how you want it. Take biscuits and make sure they're "the good biscuits". Enjoy the day.

+1 on that. Get the tank/seat join wrong and it always looks like two bikes (badly) stuck together.

TBH, with a bike that tidy you're better off biting the bullet and getting a pipe made exactly how you want. A reworked pipe off something else will struggle to look right and it will end up bugging you.

Are they bored out to 33mm ?

Lightweight bar ends ? The stock ones are that weight for a reason. Put the standard ones back on and go for a ride. At the least it will show if they are (not) the cause of some or all of the problem.

You're all missing a trick here. I fitted early GSXR600 clocks on my B12 MK1 using a MK2 trigger and pickup and got 10 mph more top speed. Best tuning mod ever.

Correct. Where the carb enters the rubber, between rubber and head or through cracks in the rubber. Have you got the standard clips at the carb/inlet rubber joint ? If you're using Jubilee clips it's possible to overtighten them and create a leak.

If the cylinder is drawing air from before the carb there will be little or no depression/vacuum/Venturi effect over the jet. Carbs don't suck fuel through the jets, it is pushed through by the atmospheric pressure in the float chamber against the low pressure in the carb bore. Air coming in before the carb will result in less via the carb = less depression etc = no fuel flow. At higher rpm air flow via leak falls as % of total flow creating some depression to allow fuel flow but not enough to feed air intake of carb and leak combined. Result ? Weak mixture. A bit long winded but an explanation of the thinking behind my theory.

If the cylinder is drawing air other than through the carb there is less flow to active the pilot system and high idle is classic air leak.

Ok, theory time (and we all know theory and real world don't always tally up). Carbs butterflies set evenly by eye should give roughly the same amount of resistance to flow (vacuum). Butterflies set to achieve equal vacuum at point of measurement at carb vastly different to each other. That suggests (in theory) that there may be an air leak between carb and head on the cylinder(s) that needed the butterflies closing to balance them using the gauges.

Was there much difference between your "by eye" settings and the ones using the gauges

Just a random thought but how about that the carbs are so far out of balance that 1 or more of the butterflies are actually totally shut ? This may result in no air flow for the pilot jets to work with on the carb(s) affected. Raising the tickover would bring them into play for it to run on all 4. Maybe balancing the carbs by eye to start with or balancing with the gauges on a high tickover may help.

There's few things you can't measure accurately enough with the length, width and diameter of your finger(s).

I want to know how you're going to hold it in the chuck !

Have you got the sprocket carrier ? Maybe some manufacturers marks on it or cross referencing the sprocket I/d and bolt pcd could narrow it down.

What grade ?

Welcome to the fun world of motorcycle racing, prepare for a season of elation, comedy and misery. As it's your first time I wouldn't bother trying to have the best/fastest bike on the grid, just one does what it's supposed to do and is easy to ride. The bike will always have a better lap time in it than the rider can manage while you're learning. Working out how to go fast on track is more about head than balls, concentrate on being smooth and getting your line right, put them together and the lap times will come. If you need a spanner man for Donington, give me a shout as it's only up the road from me. PS. No matter how fast or good on the brakes you think you are, the fast guys will come flying past. It's a totally different level to what you can do on the road. PPS. It will take over your life and be your only subject of conversation.

Are we talking about any difference between different octane levels of E5 available or between E5 and E10 ?

Ermm, can I come back to you in a minute about that ?

I'll take that as a +1 for "straight" rather than "zigzag". NB. For clarity we will not concern ourselves with tapers, surface finish or suchlike at this point.

Firstly I would like to suggest that introducing personal attack and slander into a discussion is neither endearing to oneself or affirming of your opinion. In a similar vein, pontificating that you are in possession of a piece of paper does not ensure the validity of your argument in every situation. In simple terms, the fact that I have a big cock does not guarantee I am a good shag. Secondly, Would anyone care to answer my previously asked question regarding a hypothetical inlet and it's shape ?