<html><body><div style="font-family: Arial; font-size: 12pt; color: #000000"><div aria-label="Compose body">Ah ... that would explain the 'loading up.' Essentially, the engine is flooding. But, I'd expect to see some black smoke out the tailpipe when you blipped the throttles, and I haven't noticed any (but I'll be watching for it now).</div><div aria-label="Compose body"><br></div><div aria-label="Compose body">Bob</div><div><br></div><hr id="zwchr"><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b></b><br><div><br></div><div dir="ltr"><div class="gmail_default" style="font-family:comic sans ms,sans-serif;font-size:small" data-mce-style="font-family: comic sans ms,sans-serif; font-size: small;">Bob's advice includes some excellent tips but one problem that I have encountered numerous times that causes the idle speed of a car with SU carbs to decrease until the engine stops is leakage of the float chamber needle valves.<br></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;font-size:small" data-mce-style="font-family: comic sans ms,sans-serif; font-size: small;">Oddly these valves will frequently only leak when the engine is actually running as there is no overflow from the float chambers when the ignition is left on with the engine not running.<br></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;font-size:small" data-mce-style="font-family: comic sans ms,sans-serif; font-size: small;">I have discovered that if you quickly remove the carb dampers and needles as soon as the engine stops fuel will be found to be leaking out of the main jet. <br></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;font-size:small" data-mce-style="font-family: comic sans ms,sans-serif; font-size: small;">I suspect that engine vibration causes the needle valves to leak sometimes. <br></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;font-size:small" data-mce-style="font-family: comic sans ms,sans-serif; font-size: small;">In the past I used to solve the problem by installing the type of needle valve with the synthetic rubber tips but those are hard to find these days.<br><div><br></div></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;font-size:small" data-mce-style="font-family: comic sans ms,sans-serif; font-size: small;">Michael S<br></div><div class="gmail_default" style="font-family:comic sans ms,sans-serif;font-size:small" data-mce-style="font-family: comic sans ms,sans-serif; font-size: small;">BN1 #174 <br></div></div><div class="gmail_extra"><br></div><div><br></div></div><div><br></div></div></body></html>