high performance camshaft; standard carbs

[john650]

I have rebuilt my engine with new Heiden barrels, pistons and high performance camshaft kit. Not because I wanted more power, but because they were the only new parts available.
I am in new territory here, as I have only worked with standard engines (not even XS650 engines) in the past.
I assume higher lift/longer duration cams will increase the volume of air/fuel, and compression ratio, but I have not changed the standard carbs.
My question is this: is it safe to start this engine with standard carbs, or will the engine run horribly lean and cause damage ?
What is the minimum that I need to do to the carbs in order to proceed safely?
I am quite prepared to buy new carbs, but I would like to know that the rebuilt engine is ok before shelling out more cash.

Hope someone can give advice on this.

 

[jay760]

You won't know if it is going to run lean if you don't start it, starting it lean shouldn't damage it, prolonged use while lean will, even if you buy new carbs they will still need setting up.

 

[john650]

Ok, well the engine is back in, and running. Sounds crisp.
Just a matter of checking the ignition timing is right, and then the bit that I'm not much good at (adjusting the carbs).
The mixture screw on one cylinder does'nt seem to do much, and it takes a while before it will run off the choke.
I suppose that full advance should happen at around 3000 rpm ?
Then I can see if it is running lean.

 

[5twins]

If you're worried about it running lean, bump the jet sizes up a little. You're probably going to need to do that anyway once you start tuning the carbs in, especially if you've got BS34s. A non-responsive mix screw can indicate improper float settings.