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 The previous version was outdated and no longer supported.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

Really tore into the 630...

jtemple

jtemple

Husqvarna
Pro Class
Coming up on 12,000 miles

New beefy clutch spring cups

New clutch bushing (lots of slop in my clutch)

New cam chain, gear and sliders

New fork oil

Checked valve clearance (been in spec since 6000 miles)

I didn't think the cam chain was all that loose, until I got the new one on and saw how snug it was. Very little slack on the new one, even without the tensioner installed.

The OEM clutch spring cups are very flimsy. Most of mine showed very little wear; you could still see the machining marks on them. But, to me, even the non-worn ones looked weak, especially when compared to the upgraded ones.
 
I was pretty nervous starting it up after doing all of that. I have never ripped into an engine this far before.

It took some cranking to get it going. At first, I didn't think it was going to start. It would crank and everything sounded normal, but it just wasn't wanting to fire up. 2-3 attempts later and it fired up.

After running it a little, it seems to start fine now. Idle was a bit low and I turned that up. Maybe that had something to do with it.
 
I got it running last night, and everything sounded smooth.

I was thinking it might be the iridium plug, and I was going to swap it back out for a standard plug today. This morning before work, I decided to try to start it, just to see (still with the iridium plug in place). Now it won't start it all, it just cranks and cranks. If I give it some throttle, the RPMs climb slightly while cranking, but all I get out of it is a backfire.
 
I would not think the IR plug is an issue; I've been running one for most of my 610's life without issue.

Nevertheless, it's a pretty quick change to swap back to the OEM plug to see if it makes a difference.
 
If you replaced the cam chain are you sure about all the timing marks being lined up? Being off a tooth on the exhaust valves will certainly cause starting issues...
 
I hand cranked the engine a few times while it was all opened up and everything lined back up with each turn back to TDC.
 
JT, you´re a BRAVE man! This is the moment I´d panic. Am extremely grateful I´ve got an aged (younger´n me) ex-East German bike mechanic whose shop is not far off. His main experience is with MZ 2-smokes but he can diagnose any bike correctly at 100 yards. That´s where I´d go and grovvel for help.
 
Halls says it sounds like my cam timing is off. I took the rest of the day off of work to investigate.
 
number of links between the cam chain markers were always helpful for me before removing the chain but you are beyond that point unless someone with a 630 that has not been worked can provide that number for you.
 
jtemple said:
Halls says it sounds like my cam timing is off. I took the rest of the day off of work to investigate.
Click to expand...

Keep us posted. I keep thinking back to your comment about how snug the new cam chain was. Doesn't sound right to me but of course I don't know if what you call snug and what I do is the same. Could have had uneven chain placement (more links on one side). While you hand cranked the engine when still opened up did you feel the chain tension in multiple locations? Possibly chain then jumped after you first started and ran the motor??

_
 
Success!

My exhaust cam was off by one tooth. The outer cam marks lined up with the top of the head, but the inner mark on the exhaust cam did not line up with the mark on the cam chain gear.

I reset the exhaust cam using the inner marks and lo and behold, the outer mark sat higher than the head when the bike was at TDC.

The inner marks are darn near impossible to see. I had to do it with the cam brackets removed and use a flashlight and inspection mirror to see them very well.

One trick I did was to get the cam on the mark with the dots up where I can see them, then slowly walk the cam down into its place, ensuring the teeth didn't skip in the process.

Once I got it back together, it fired right up. I have my bike back. :)
 
Good job troubleshooting. Did you recheck your exhaust valve lash after? I would think slightly different now.

Also curious as to how both your chain sliders looked? Any obvious wear?

_
 
I checked valve clearance before the initial tear down and it was in spec. I did not check it again afterward; probably should have, but I didn't expect it to change.

The chain sliders showed no noticeable wear. I replaced them anyway. The shop manual says to replace then when they wear down to the metal. I couldn't even see where that would happen. They looked identical to my brand new sliders; no grooves in them or anything.
 
After fixing the timing, It blew some black smoke when I first started it up. That cleared up after a few seconds.
 
jtemple said:
I checked valve clearance before the initial tear down and it was in spec. I did not check it again afterward; probably should have, but I didn't expect it to change.
Click to expand...

Yeah it shouldn't change but then in your case you would have known something was up when you found the exhaust valves changing. Not sure how much one tooth would have changed it but I bet noticeable.

_
 
jtemple said:
My exhaust cam was off by one tooth. The outer cam marks lined up with the top of the head, but the inner mark on the exhaust cam did not line up with the mark on the cam chain gear.
Click to expand...

Funny how I can troubleshoot from 2000 miles away. If it were my bike right in front of me there is no way I would have thought of this. :)
 
Before & After Clutch Spring Cups:

IMG_3072.JPG


IMG_3073.JPG


IMG_3114.JPG


IMG_3115.JPG
 
So it looks like he didn't use a fancy press for the rivets, he just heated them up and bashed in the end to flare them?
 
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