twobone Posted June 30, 2011 Share Posted June 30, 2011 Just note one error - float height is 15mm not 6.5mm http://www.teglerizer.com/dcoe/rasorcom.htm Link to comment Share on other sites More sharing options...
bsimon Posted July 1, 2011 Share Posted July 1, 2011 The teglerizer site references early Weber 40DCOE carbs with round brass floats. They show a correct 8.5mm with the needle closed. Caterham and Lotus both used this figure on early cars. For later typo 151 (40DCOE) and typo 152(45-48DCOE) carbs with synthetic (squared-off plastic) floats, the setting is 12mm. Caterham used this figure as well. There are some individual engine builders that alter these figures for their own special recipe. God and the builder only know why. Caterham does do some special drilling of idle progression holes, but as far as I understand, that's the only permanent machined alteration. Link to comment Share on other sites More sharing options...
twobone Posted July 1, 2011 Author Share Posted July 1, 2011 Just to be sure as I have the later 151 type carbs with the plastic float and a 1.75 needle valve. Its 12.5 with the float compressed fully against the needle valve? I just set it at 8.5. Oops Link to comment Share on other sites More sharing options...
bball7754 Posted July 1, 2011 Share Posted July 1, 2011 Set with it just touching the ball on the valve, I believe. I bought a long 12mm bolt and used that to measure. Easier (to me) than trying to get a micrometer in there. Steve Link to comment Share on other sites More sharing options...
twobone Posted July 1, 2011 Author Share Posted July 1, 2011 That's what I thought....just touching at 12mm Link to comment Share on other sites More sharing options...
twobone Posted July 1, 2011 Author Share Posted July 1, 2011 Well whatever I did, its working. No more gas leaking on my battery and a nice progression between idle and main jet Link to comment Share on other sites More sharing options...
bsimon Posted July 1, 2011 Share Posted July 1, 2011 A shaved bit of plastic or wood 8.5mm X 12mm that's just long enough to span the cover flanges works a treat. Just flop it one way or t'other depending on the vintage of the Webers you're working on. Since you guys are fiddling with DCOEs, do a little research on the issue of internal throttle return springs. They can break and jam at WOT. Not a fun experience, I assure you. Only use external return springs. A redundant return spring is a good thing as well. Caterham used to remove the internal springs, but you should still check to make sure. If you have the carb off the manifold, the spring can be removed by unhooking it from the bell-crank between the bores and lifting it out through the top of the carburetor with the cover off. 48DCO/SPs as used in the VX powered Caterhams have no springs. Link to comment Share on other sites More sharing options...
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