walbro 990

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Aussie MT Rampage

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I have a zen 4 bolt 29.5 with WB990 HSN 2 1/4 turns out and LSN 2 1/4 turns out from closed this is how it was new out of the box and it ran and started great with stock muffler and pipe


I just bolted on a side mount tuned pipe


My question is should i start leaning or richening the HSN due to the new installed tuned pipe to gain the most performance
 
Changing pipes is like changing engines. You should really go back to stock carb settings and tune by idle speed and plug color. Also, those carb settings are WAY too rich. Reset the LSN to 1 1/4 out and the HSN to 1 3/8. Those are the stock settings and are good for all engines.
 
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On my 46 cc is stock LN 1,25 and HN 2,5 and with my new custom pipe i ve LN 3 and HN 5 ,so if the engine run great on this setup ,i ll let it. With the stock can my engine rungreat on 1,5 and 2,75.
 
I know the maual that came with my engine says factory setting LSN1 1/4 HSN1 3/8


But before I even started it I checked the setting and both HSN and LSN were 2 1/4 from closed so I left it at that and It started and ran great with stock can


Now that it has a tuned pipe I need to retune to get the most out of the pipe and as Alex mentioned you richen the LSN and HSN needles when upgrading from stcok can to tuned pipe in this correct?
 
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