I put a biturbo on my sachs and i think it needs more air. The plug is a little wet and black. What effect will i get by moving the needle in the carb? do i just start drilling the air box til its right? Thank you everyone
I put a biturbo on my sachs and i think it needs more air. The plug is a little wet and black. What effect will i get by moving the needle in the carb? do i just start drilling the air box til its right? Thank you everyone
505/1a on a suburban
No you need to rejet. First off, ditch the old plug. do a plugchop and rejet the main jet. if you don't know what any of these terms are, look on fred's guide under articles.
word. search is your friend. and ps- sachs square bing jets are hard to find.. try doing alternatives first like drilling your airbox.
what is plug chop??
search is your friend.
if you're convinced you're running too rich, then yes either adjust your needle or deristrict your airflow. By lowering the needle you can lean out your mix a bit, but as far as i know this really only affects from 1/4 to 3/4 throttle. If you can find some jets, rejet. If you cant, then you'll need to drill holes or deristrict in some similar manner. aka take your airbox off and experiment with varying levels of pantyhose, laundry sheets, screen window mesh, performance filters, etc, to let the perfect amount of air in.
But what i dont get is how after putting on a biturbo you now run too rich... i was under the impression that expansion pipes required _more_ fuel, not less...
Sorry Robert, Square bing jets are pretty much unobtainable(not sure if they even made different ones) I have a 505/C w BiTurbo, Bing 12mm w/58 jet and I'm definitely running a tad rich, with panty hose filter. Which is wierd even with a practically open airbox setup. Which carb do you have robert? most likely a 10mm carb!? what jet size?? If you take apart your carb, your Bing has only one jet, which can be unscrewed with a flat head screwdriver. Stamped on the side of the jet is a number (reeally small) thats your jet size. This is a good opportunity to clear the jet and the needle and holes in your carb.
actually most sachs bings are 12mm carbs with 14mm intakes. they aren't hard to find either. check ebay or handybikes.
There is another brand of jet that works with that carb. They use a completely different numbering scale so you have to cross reference. I want to say its a Dellorto but I'm not sure. Call Shaun at Myron's mopeds he can tell you what it is. He also has a conversion chart that cross references all brands of jets and drill sizes.
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