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Re: Constellation top speed

Posted: Thu Aug 18, 2022 7:34 pm
by Jakub
According to manual it's 3/8-7/16" or 9-11 mm in regular language. Mine are 14-16 mm. However I would guess factory recommendations are for fuels of the day. Modern fuels are of higher octane, which means better anti knock effect, which means they burn more slowly so require bigger advancement.

Also those old engines are not exactly the same, every is like hand made, every single one is slightly different, every has some wear and tear. So keeping faithfully and strictly to factory setting, in my opinion is pointless. One should start with factory setting and try to find best position by trial and error

Re: Constellation top speed

Posted: Sat Aug 20, 2022 8:49 am
by Vince2
Hi, the fact remains that you are running double the advance timing. Also you still haven't stated in which direction you advance the lever? Vince

Re: Constellation top speed

Posted: Sun Aug 21, 2022 12:27 am
by Daiwiskers
Another thing that may be part of the cause is the fuel we are getting these days
This won't be the same for everyone but I have had to go up to a 40 pilot jet and down on the main I think I am down from 2 sizes on the main, the needle jet and slide I am still experimenting with

Some people are saying the e10 fuel is fine but not for the vehicles in our household my Ann has lost about 6mpg in her car a little Peugeot 108 apparently fine to run on e10 but it's definitely affected fuel consumption it also shakes a bit more on tickover

As has already been said you are running a lot of advance I would have thought a mm or 2 extra advance would have been plenty it may be worth retarding the timing and having a look at fueling remembering this e10 fuel goes off even quicker than e5 it also turns into a horrible gunk when left in a fuel system

This may just be a spanner in the works but if no amount of playing with the timing improves things for me it's time to look at fuelling

Hope this helps and not hinders
Cheers Dai

Re: Constellation top speed

Posted: Sun Aug 21, 2022 8:24 am
by Daiwiskers
A Dyno run may just save you a load of heartache
Better than my last post eh Dai

Re: Constellation top speed

Posted: Sun Aug 21, 2022 12:40 pm
by Jakub
Vince2 wrote:
Sat Aug 20, 2022 8:49 am
Hi, the fact remains that you are running double the advance timing. Also you still haven't stated in which direction you advance the lever? Vince
Personally I wouldn't consider doubling 11,1 being 14.

As for direction of ignition advance lever
Retarded
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Re: Constellation top speed

Posted: Sun Aug 21, 2022 12:54 pm
by Jakub
Hi Dai
I couldn't agree more on the modern fuels. I've got few classics, bikes, cars and one truck. Modern fuel is a pain, it's good for about six months and it starts to separate, also one of additives is alcohol and alcohol is highly hygroscopic. It attracts water.
One of my bikes is almost 90 years old and 4o years in my possession. Up to some years ago inside of fuel tank was nice and clean. Now with modern creations there is alcohol, hence there is water and fuel tank started to rust.

It's not only oldtimers who suffer, leave modern fuel with youngtimer with fuel injection. The repair bill will be massive.

I am adding this stabilizer stuff to fuel tanks in my vehicles. I am not sure if it does any good but there is not much one can do.