• Husqvarna Motorcycles Made In Sweden - About 1988 and older

  • Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

    Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.

    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

Needle valve ass question

Northern Husky

Northern Husky

Husqvarna
AA Class
hello,

the specs for my carb say i need a 3.0 needle valve (throttle valve as ive seen it called), if i run 4.0 what will be the difference?

ls there a 'rule of thumb' to ajust using a different pilot jet etc?

thanks
 
Northern Husky;98169 said:
hello,

the specs for my carb say i need a 3.0 needle valve (throttle valve as ive seen it called), if i run 4.0 what will be the difference?

ls there a 'rule of thumb' to ajust using a different pilot jet etc?

thanks
Click to expand...

A 4.0 is leaner than a 3.0. The reason it is leaner is more air passage across the pilot jet venturi with LESS throttle opening. I always start with the recommended pilot jet and if I have to give the engine more throttle to keep running at idle my throttle is too rich. Opening the throttle more to keep the bike running at idle and off idle is then allowing more air to pass through the carb but also starts pulling fuel from main circuit also making it more rich!
I try to tune my bikes so it will start easy and idle well with the least amount of slide opening. If I have to screw idle screw in more and dont get response from idle air/fuel screw, I'll lean my slide more. It takes time but you want to be able to have good response with the idle air/fuel screw. This keeps all the carbs circuits working like they are designed to, somewhat independent of each other with some overlap. I always jet my bike for WOT high load and then clean up the idle circuit. Never lean the main to clean up the idle. This is just the way I do it and there could be better ways and please chime in.
 
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