Timing question

Theres no vac pipe ,will this make a difference ?

 

Thank you

 

Now set at 30 deg at high revs, time for a test run , fingers crossed.

 

It had quite a bad flat spot at low revs and a bit of miss-firing higher up the range , so ive reset at 32-33 btdc and it seems better but still a little miss fire at high revs
i assume this will be to do with the carbs rather than the timing

 

is it a stutter, or a popping through the carb or exhaust...?

Have you set the tappet gaps?

 

Its more of a stutter not popping
Ive set the tappets once , after the valves had been re ground , just waiting for it to cool down and i will go over them again.

 

What twin carbs do you have??

 

Solex.

 

As above, set it to 7.5* with a light bulb. You need the engine running. Your engine should run fine with this, as a starting point.

 

i was told to err on the side of caution with timing and always err on the retarded side rather than advanced as it will, so im told, be safer..at least that way you can get to the rolling rd for testing

 

Just remembered that you're off to the RR... I wouldn't worry about the flat spot too much at the moment, as it's likely to be a slight fueling issue

 

Thanks for the help everybody

 

Is there a standard size of jet for twin solax 40's on a 1641 ,or is the size determined by the engine tuning fellow

 

You can get a rough out of the box jetting, but final size is determined at the RR, as they test your engine under load