carb tuning

[DAVID L]

I have a pretty standard HPC with 45 dcoe webbers now experiencing a bit of a flat spot low down the revs. I live in the Caterham area, any recomendations for good check on timing and carbs? Ta in advance. DAVID L

[stevefoster]

If it's only a tuning job then twiddle the slow running screws one at a time

allowing plenty of time between each twiddle to allow the revs to rise or fall

until you get the fastest revs. Then give that slow running screw a quarter of a turn anti clockwise (richening).

 

When you have done this balance the carbs. A sychonisateur (spelling?) is a good aid but a bit of hose tubing and practise will get you there too.

 

Then run the engine until warm. Hold her at 1500 rpm for 30 secs and then swtich off.

 

Look at the plug colour and adjust as necessary only an 1/8 at a time. Over a few runs where you hold at 1500 rpm and then switch off look and adjust, you will have a sweet engine giving a grey plug colour across the board and a lot of satisfaction.

 

This works for me....