Yes, im still having probs.

This is an easy question... answer rich or weak.

On my bike, when youre full throttle above 8k the bike runs perfect. If you roll the throttle off however and then come back on the engine will take a second or two untill it picks up. This is only above 8k

Its really bad comming out of a corner. It feels like its almost bogging. So im guessing it rich. The plugs look a good colour and the bike runs (apart from this on off throttle) perfectly.. so what do we recon.. rich or weak?

Cheers

Are we talking about you? I've seen the '45, so I know you're rich. And you're quite a big lad, so I'm guessing you ain't weak.

So there you have it, rich, not weak.
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

The NSR Dave not meeee.

I tryed some HRC "C" needles and that cured the on off throttle thing. but now its a little weak in the mid range and wont pull clean so i guess i will tryin lifting them a clip..

Oh right. Sorry!

Can you afford some dyno time? It's the fastest way to get it right. Make sure you keep records of all the stuff you do, including the temp on the day, and how it felt. Looking back over my track notes made it a helluva lot easier to go in the right direction when the power delivery was poo.

Have you the full HRC setup, with blocked PJ's?
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Dave... i run a dyno!

The dyno is very good but they do have limits. Its very hard to set up a 2 stroke with one as you cant hold them on any type of steady load for very long unlike a 4 stroke. Ive got this far with the dyno but this last bit is really just the fine tunning needed on the road. You just cant simulate some road conditons on a dyno. Shes over 65 horse tho now so we are headin in the right direction.

Im using the HRC needles but i still have the PJ working

Ah, I couldn't remember if you did or not. I know what you mean about their limits, and as you say 65 is not to be sniffed at.

Do you have the HRC emulsion tubes to match the needles? Standard filter and opened up lid?
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Yeah im running the tubes too but with a HRC filter and the lid mod. I raised the needle half a clip at lunch and i think its almost cured all the probs. It amazin what a differance .5mm makes on needles.

See you at cadwell dave?

Nah, 'fraid not. I'm doing two track days this month already, and have just forked out £200 for race entries at Pembrey too.

Cadwell is just too far away for me. I'm going to Llandow on the 14th though, and since it's (1) half the distance, (2) on a weekend, and (3) only £69, you should come along too.

Anyone else? Sat 14th Aug, £69 for the full day...



Anyway. It is quite amazing the difference the needles make, especially when you can hardly see the differece in them with the naked eye.

Not sure raising it helps the midrange does it? I've a graph on carb setting at home, with a detail of what affects what in what rev band. I'll try to dig it our tonight and post it - but I'm attending a barbie in the next hour or so, so don't be too suprised if I forget!

From memory, I think you need to slim the needle to improve the midrange, and the C is richest isn't it? Or is it the A? Damn this heat haze.
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

C is the weakest, im running clip 4 + a washer.... has helped the middle no end.

If you have to use a washer, then there's sommit else you should be changing. Maybe the jet itself can go another size down, then you can return to the B on middle clip...
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

There are 5 clips so i wasnt fully lifted.

Anyway it doesnt matter now. I put the stock pipes back on and got within 2bhp of the race tygas and picked up over 8 in the mid range. They may weigh quite abit more but the bike runs so much better and not one single glitch. So stock pipes it is for me!

Funny that as Bills NSR makes the most power with stock pipes too. Others may rev on more but it seems nothin can beat stock overall.

You're getting within 2 hp of the race TYGAs with the stock pipes? Can you explain how that works, and what the HP numbers are? My understanding is that the stockers are very restrictive and not tuned for power at all. Is that incorrect?

From all the work i have done on the dyno overall stock pipes seem to be best. I have an MC18 which with stock pipes, swarbrick cans, moded air box and jetted to suit makes 62bhprw

Fitted with the Tyga race pipes, the very most i got was 65bhp. The bike although pretty smooth lost a huge amout of torque below 9,000rpm. it woudl still pull well but no where near as good as the stock pipes.

My frend Bills MC21 SP went the same way,. His motor is lightly ported and made 65bhprw with stock pipes, swarbrick cans, HRC jet kit, no air box.

He went to the exspence of nearly £700 for a set of Gibsons pipes to be made up and lost 1bhp. But he did gain 1000rpm of over rev, He then got a set of Nikons which we wont even talk about their power out put.

So between us we have we have had, 2 sets of tygas, gibsons, nikons, and stocks.

The only ones to make better power where the second set of tygas but at the exspence of a huge about of bottom and midrange for less than 3bhp. So we are both now runnng 60plus with stock pipes and cans. The tygas do look very nice tho :D

I think stock pipes are very very good. Hell that went on for a long time lol

How did you make the Swarbrick's cans work? Do you have to cut off the stockers and weld on a plate for attathment.? I'm interested because I just decommissioned my track day NSR and it's back on the street. I would prefer to run the stock exhaust, but I didn't want to settle for no power.

Can you post the dyno graphs? I want to see the midrange, if possible. Also, what kind of dyno are you using?