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 The previous version was outdated and no longer supported.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

Finding TDC

390wr Jon

390wr Jon

Husqvarna
AA Class
This is probably a stupid question so please don’t hammer me on it.


I’m in the process of installing a Powerdynamo system in my 1980 390WR using a dial indicator through the spark plug hole. When the piston nears TDC there is a slight resistance when turning the flywheel. The dial indicator then stops, whereby I can rotate the flywheel back and forth ever so slightly without moving the dial indicator. When I continue turning the flywheel toward the downstroke, there is a similar slight resistance.

Note that there is no slop in the connecting rod to crankshaft bearing or connecting rod to piston.

So is the correct procedure is to set the timing on the downstroke as soon as the dial indicator starts to move again? I plan on retarding the timing about 1.8-1.9 mm. Is this done by removing the flywheel at its TDC and rotating it counterclockwise (without moving the crankshaft) to achieve the 1.8 mm retarded timing setting?

I used to be reasonably good at this stuff but I guesss my gray matter is going south as I get older…..
 
I used to be reasonably good at this stuff but I guesss my gray matter is going south as I get older…..
Click to expand...
I'm right there with ya brother. :oldman:

I've have zero experience with aftermarket ignitions but I do have a fair amount of timing experience with a Femsa and Motoplat. An ignition fires before TDC. So, using your dial indicator find TDC then rotate the crank backwards the recommended timing amount which you indicate is 1.8-1.9mm BTDC. At this point a mark on the flywheel must align with the a mark on the stator. This is where the plug will fire.

As for moving the flywheel back and forth one millimeter at TDC without moving the dial indicator, IMO thats normal. The resistance you mentioned isn't something I'd say is normal. I will say that there may be a different feel to turning the crank past TDC but there certainly shouldn't be resistance. If this was my project, the head would be removed for a visual inspection.
 
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