Z1OwnersClub GB

Hi, The bike is pinking under load at approx 4000 rpm, if I back the throttle off a bit then accelerate again, it reduces the fault. I have strobed the timing and the the advancer is fully forward by 2500-3000 rpm not the 4000 rpm it states in the manual. Could this be the problem?
Also at idle the mark is on the F, in the book it says the mark is to the right, mine is to the left (it is not on the T mark), is it an error in the book, as some pictures show the same marks as mine.
The bike is 1170 Wiseco with Kerker exhaust with 33mm Kehein carbs with no filters.
It runs fine apart being a little rich.

Cheers in advance
Rob

Hi fully advanced by 3k sound about right.pinking as i have always understood is when fuel ignition is retarded.you have set up gaps on points if you still have them fitted to 14 thou at F for 2 and 3 and 1 and 4 pot I take it,try advancing ignition timing slightly to see if matters improve or get worse also what plugs are you using ? Cheers Paul J..

Pinking is when the fuel ignites before the spark... so the ignition is too advanced (in theory).

The shite fuel around nowadays has a lot to answer too. The cure is either use a higher octane fuel (Shell V -power is supposedly quite good) or try an octane booster additive, or reduce the compression ratio (not really an easy option ) or use less throttle opening at low revs

Pinking is when the fuel ignites before the spark... so the ignition is too advanced (in theory).

The shite fuel around nowadays has a lot to answer too. The cure is either use a higher octane fuel (Shell V -power is supposedly quite good) or try an octane booster additive, or reduce the compression ratio (not really an easy option Rolling Eyes ) or use less throttle opening at low revs Confused

Exactly what Piggy said.

If youre 1170 now you have 1089 barrells on a ??? 17mm or 18mm wrist pin.

Comp ratio without cylinder spacers on 17mm wrist pins will be in excess of 11.00:1 (pinking central)

Tested mine yesterday and got 11.20:1
Very glad i used two thick base gaskets now.
Really could have done with a Debbens spacer

Full advance could be 2 degree less than full factory advance in the manual for running in and i use it all the time now as it wont take full advance with my set up.

You can ignore the timing marks at idle and low throttle settings for the most part. The important thing is the onset of advance curve afforded by the spring tension. If the springs are slack or weak then you need to tighten them up. Full advance should be achieved close to 4000 and i would suggest that you dont hit full advance 'till the upper reaches of the 3000 band and then, topping out at 38 degrees when using standard pump fuel.

In practice this means; the dash which is the left hand one of the parallel pair at 4000 RPM
Drop the revs on the tick over screw to three thou and you should be fluctuating somewhere near mid point of 'parallel pair and the 'F' mark.

All thing being equal; on idle then, you should see the 'F' mark line up hopefully a little to its left hand side meaning its to the right of the static dash on the inner case.
Overall intention here is to run it a little retarded.
This will also have the effect of leaning out the mixture strength.
Maximum power is achieved just a little weak of the optimum burn ratio. In practice this would be an engine that would last the year if youre lucky.
A little rich is no necesarily a bad thing wheras a little lean will destroy it fairly quickly but it will go like stink!

Similarly; Piggy said use less throttle at lower revs. Although mine is now the same as yours i have to drive it more like a two stroke and dont let it labour in the taller gears.

Pinking (autoignition) is death to engines. Have a look at you're plugs. Any hint of tiny shiny ball bearings attached to the insulator and you need to stop and take some remedial action fast.


AL
[/quote]

Dont know what happened there. Mines the bit in white.

AL
Hope this helps

Al, I think you've got 3 x "quotes" instead of the 2 x

Hi all, I put some Vpower fuel in and it has reduced the pinking considerably. I got a colourtune and set up the idle, it was running rich, I will take it out for a ride tomorrow to check it. It still runs rich through the rest of the range according to the colourtune, so I will look into this later, once I have checked out what the main jet sizes are.
Cheers Rob