Hi All,

Had my GPZ1000RX motor in at the dyno today,Was really wanting to check my fuelling,Turns out my fuelling was good(AFR 12.5/1) in 5th gear full throttle,What we noticed today though was that I started to lose power at 9400rpm and peak power was 122 bhp at crank(at 9400) I still had another 2000 rpm to go but it was just dropping power !!!
The engine has been dyno-jetted running 140 mains(dyno jet mains/real world 1.6mm)
Do these figures sound correct ?
I was hoping for a little more !! Or was I just being optomistic ??

Any information would be much appreciated.

Craig

I'l admit that seems a bit disappointing.

What sort of age is it??

How is the compression?

Have you adjusted the valve clearances?

What sort of air filter do you have?

What sort of exhaust do you have?

I run 200 main jets! Which is a little on the rich side, but was recommended to me by a guy who was using a ZZR engine in his championship winning Jedi.

He said there was no point in going larger than 200 as the hole in the casting that lets fuel in is 2mm in diameter.

Mike

I thought the 1000RX was a slightly detuned ZX10? If so that sounds about right, the ZX10 gives 125 BHP as standard (137 with the derestriction) so 122 BHP for a (not new anymore) engine sounds quite reasonable - a little surprised it's that far down the rev range tho' I would definitely recommend checking tappet clearances & balancing the carbs, & would agree that any restrictions on air intake or exhaust can have a dramatic effect.

The engine is.....1986 model so is a fair age !!
I have no idea what the compression is as of yet,will need to check and see.

I set all the valve clearances not so long back,I set them all a little on the slack side of the settings !!

The airfilter set up I have is 4 individual pod filters sitting over the orginal trumpets(no airbox)

The exhaust is a micron end can with a 4 into 1 manifold(manifold looks to be a homemade effort) This was on the car when I bought it !!

I balanced the carbs at the same time as I done the valve clearances so these should be good to.

The GPZ1000 is a lesser model of the zx10,It uses the same head as the gpz900 which has a different cam/rocker set up and also has smaller valves compared with the zx10 b model/ZZR 1100

I'd be tempted to try a run with the filter socks removed and a sausage type filter or airbox instead.

AFAIK those individual filters can be quite restrictive.

HTH

Mike

Carb icing ?

Used to affect these.

Still one of the best bikes I've owned - fond memories

Thanks for the replys,I'll have a go with the filters removed,I just done a quick search and these pod filters don't seem to have a good reputation at all,I do have the orginal aribox from the GPZ but it is a real cut and shut effort !!

Having seen carb icing mentioned, the heat pipe for the carbs is very prone to blocking up (there's a little filter in the end), worth giving that a good clear out.

I have the carbs connected to the cooling / heating system on my car,

but carb icing, reducing power on a rolling road session? Where is your rolling road? Alaska??



Mike

I don't have the carbs connected to the cooling system on this !!