There's a couple types of 650, a 4150 and a 4160. Do you know which this is? At least one company makes replacement jet blocks that have externally removable jets so you don't have to take the whole carb apart to make a change.

This: http://www.summitracing.com/parts/php-15001

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250