PINKING GOLDIE

[Goldie]

What are the main causes of pinking when taking away under load on hills?

I am running a 350 Goldie with an RRT2 gearbox which is slightly overgeared to normal gearing due to the recently fitted primary belt drive..

When I take away and slipping the clutch like mad with a lot of revs to get going the engine pinks badly, and once the clutch is fully engaged and away the pinking disappears. It aso occurs when going up hills under load, only changing down and reving the engine harder it disappears. I do not let the engine labour on hills.

Any ideas???

[L.A.B.]

What are the main causes of pinking when taking away under load on hills?

It generally happens because the octane rating of the fuel isn't high enough for the compression ratio of the engine, so use higher octane fuel (if you can find it?) or, lower the compression ratio? Sometimes retarding the ignition by a few degrees can help.

[Goldie]

What are the main causes of pinking when taking away under load on hills?

It generally happens because the octane rating of the fuel isn't high enough for the compression ratio of the engine, so use higher octane fuel (if you can find it?) or, lower the compression ratio? Sometimes retarding the ignition by a few degrees can help.

Thanks for the info.

Yes I do have a manual ignition lever and I will try it next time I go out for a ride.

The engine has been bored out to 400cc, but the compression is not brilliant.

I have a tin of octane booster which I can try, but will it work?

[L.A.B.]

I have a tin of octane booster which I can try, but will it work?

Some do, but a lot don't! But no harm in trying I suppose?

[twolitre]

"Pinking" is caused by an ignition setting too far advanced for the conditions under which the engine is working. On bikes (and old cars) with a manual advance/retard lever it is the rider/driver who must get used to altering the setting to suit conditions. Best performance is obtained just short of the advance which causes "pinking". Glowing carbon deposits or wrong heat sparking plugs can cause "pre-ignition", which also produces "pinking".

However, "detonation" where the mixture charge in the engine explodes rather than burning and is easily confused with pinking and is caused either by a petrol of too low Octane for the engine compression ratio or normal running temperature. The only answer to that is higher octane fuel as L.A.B. says or attention to cooling if the engine runs too hot.

Jim.