• 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 The previous version was outdated and no longer supported.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!

Closed throttle issues

grouty

grouty

Auto Lover ...
Finally got the 78 390WR back on the road after a long lay off. Yes, cleaned carb, filter done etc etc.
I had this problem last time I rode it a few years ago.
Plug is a NGK B8ES with a change today to the iridium version.
When decending a hill with the throttle closed, every now and again it "pings" and will lurch forward on the power stroke created. Today, after an hour or so riding I noticed the revs did not always drop back to idle when stopping. A blip of the throttle usually cured this. Maybe this is not accociated with the pinging. The carb is new, as well as the inlet rubber, throttle cable and twist grip. The engine was rebuilt not long ago with all new bearings and seals.
My thoughts on the pinging are maybe the reeds are tired ?
It is very annoying decending a very step wet rocky decent with it pinging just when you don't really want to be going any faster.
 
Was a new base gasket used and have the head nuts been properly tight all along since the rebuild? I have seen mechanics wave a propane torch (not lit) around carb and stuff like that to see if a difference in running sound could be detected.

That not properly coming down to idle is one of the things I noted as I played with needles and pilot jets on my pwk carb swap. I cant really tell you what changes to make but going richer on something probably will cure it if it isn't something like I mention above. A lot of my stuff doesn't always come down to idle exactly the same but usually works good enough not to tamper with it. Having hardly any water in a 1998 125 will do it as well I know from experience.

If the decent is long enough just shut it off that takes away a good deal of stress.

Is what you have pinging which is detonation without the spark plug starting it or four stroking where it fires on some but not all cycles?

Was the head polished? (make shiny like a mirror) I read on here not to polish the head and if you must polish something polish the piston. This symptom might be what happens.

Fran
 
Not coming back down to idle usually means you're lean somewhere, if it's not mechanical. So first make sure you've got a nice clean throttle and cable and that there's a bit of slack in the cable at idle so the slide comes FULLY back down. If it's not mechanical, then it's a lean mixture somewhere. If you work the bike hard in that lean range the temps go up (especially on these air-cooled bikes), then when you chop to idle, the bike acts lean at idle due to the temps. A blip of the throttle sends additional fuel mixture in and cools things off. It doesn't take much for this to happen. So... look to richen the needle jet by 1, or try a lower clip/higher needle position, or a richer main.

What's happening to you on the downhills I call "Bing" rather than "ping," just to distinguish it from a ping you might get while on the gas if the octane's too low. On a downhill this can be from either too rich at idle (fuel builds up a bit then goes POW) or too lean, in which case it's like a single firing of your "idle doesn't come down" problem.
 
Fran - There is no four stroking, as Picklito says, it is more of a "bing". I tried a steep decent after a gentle cruise to cool the motor. Still the same. After maybe 5-10 seconds of closed throttle on the decent it bings.
The complete intake system is new, apart from the reeds. Yes, it had a new base gasket, and yes the head is tight and has been checked.
Maybe it is sucking through the pilot jet ? If so why ? More to the point, if it is, how can I stop it. None of the two strokes I have had down over the years has done this.
 
I agree with the a bit lean theory, close the air screw a quarter turn, also helps starting when cold. It is not a trials bike so a litle richness on opening the throtle will not matter. Any way what are you doing going slow
smile.gif
 
Thanks Steve. I will try the air screw first as it's easy. I have a new set of reeds here to in before I do it though. Just doing that will alter things a bit.
Slow.... me ..... not usually, but you can't overdo it when out green laning
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Nice to see it out and be able to ride it after 6 years in the workshop though.
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how is your float? not surging fuel into the engine on deaccelaration...? (you spell it!)
 
Ahh yes ... the "Bing" factor.
I put a new set of Boysen Dual Stage reeds in there after writing that. That was the start of many jetting issues ! Suffice to say it still went "Bing"

A rebuild followed some while later. All new bearings, seals and gaskets. Still went "Bing"

Fitted a new Lectron 38mm carb a few months ago. Totally transformed the bike. It was always a good starter, but now it will burst into life on a half hearted kick. Runs sooo much better. What about the "Bing" you say ....... it still does it, just not as often.
I guess I will learn to live with it.
 
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