• 4 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
     TE = 4st Enduro & TC = 4st Cross

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 The previous version was outdated and no longer supported.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

04 TC450 Exhaust Cam Question

HardCoreHusky

HardCoreHusky

Husqvarna
AA Class
I just bolted everything together, doing a head swap, checked everything , and it fired it up. I have a big "clicking" coming from the top of the head. That little cam like disc on the end of the exhaust cam, the little protruding end is riding on the cam follower causing a the clicking but it appears to me that it should be rubbing on the side of the follower, when the decompressor is used? I'm off to work am unable to look it up on the service manual, just wondering what the hell that is? Some part of the decompression circuit?
 
HardCoreHusky said:
That little cam like disc on the end of the exhaust cam, the little protruding end is riding on the cam follower causing a the clicking but it appears to me that it should be rubbing on the side of the follower, when the decompressor is used? I'm off to work am unable to look it up on the service manual, just wondering what the hell that is? Some part of the decompression circuit?
Click to expand...

You talking about this thing, in the pic below?

If so, it's the auto decompressor, and a small, weak spring keeps it pushed out to where the ear will ride on the cam follower and bleed off about half of the normal compression, for starting. When the RPMs are above starting levels, (over 500-800 RPMs), the weighted side opposite the ear works to pull the ADC in towards the cam, thereby pulling the ear of the ADC from hitting the cam follower.

If your ADC ear continues to hit the cam follower at idle RPMs (1600-1900 RPMs), then something is preventing the weighted side of the ADC disc from being pulled in by centripedal force and thus clearing the cam follower. In the pic below, the screwdriver is acting as the action of an idling engine and the ADC ear is pulled away from where is can ride on the cam follower. The spring is in the weighted side and it could be jammed/crushed/messed up, etc.

The second pic shows the weighted side of the ADC on top, with the ear visible at the bottom riding on the cam follower.

20k535u.jpg


HuskyADCRocker.jpg
 
OK, I'm getting closer I think. I removed the exhaust cam, thoroughly cleaned that cam spring etc and checked everything else, moved smoothly and easily, all looked good. Checked the cam chain tensioner, you name it, all looked good. Clearances spot on, Bolted things back together and same noise!! So I yanked the motor again and stripped the head off to start at square one to see what it could be. Lo and behold as I remove the head gasket, now is when I notice that the fire ring is a smaller diameter than the bore! Halls sent me a gasket most likely for a 250? And I didn't match it up or check when installing it. I just dropped it on, slid the head on and torqued it up. The pic shows the original gasket on top and the bottom gasket is the one Hall's sent me. And the side of the gasket that faces the piston looks to have signs of something hitting it. You can see that in the next pic. I'm going to say that was my problem, what do you think? Yeah, major "Bonehead".....:doh:
 

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Thanks for posting the solution, might help someone down the road.....although, this may be the only time this ever happens....
 
My '07 TE250 has a problem with the ADC.. It just stopped working and now the e-starter can't turn the engine over.. I can hardly kick it over.. The little De-Comp lever works fine and the e-starter will spin the engine with it pulled in. But let it go and no dice.. ??? Can I easily pull the valve cover and check the ADC cam or do I need to take it in? Any help is appreciated..
 
Shotgun Jimmy said:
My '07 TE250 has a problem with the ADC.. It just stopped working and now the e-starter can't turn the engine over.. I can hardly kick it over.. The little De-Comp lever works fine and the e-starter will spin the engine with it pulled in. But let it go and no dice.. ??? Can I easily pull the valve cover and check the ADC cam or do I need to take it in? Any help is appreciated..
Click to expand...


You might wanna check your starter brushes. I had the same problem as you and I spent $100 fixing the ADC and then I discovered it was my starter.
 
HELP !!! I re-shimmed the Intake and Exhaust valve clearances and it still won't turn over with the e-starter. The Starter is clean (disassembled and checked) and the Exhaust valve clearance is now .011". Still a little wide by .003" but if i went with the next size (235mm) shim it would be too far closed by .002" so what the hell ?

The ADC seems to work ok.. it pivots and clicks the valve open as it should. Could the ADC can be too far worn to open the valve ? Im stumped… Any ideas are more than welcome.. I need to get her working for the Desert 100 in April .!!
 
Shotgun Jimmy said:
HELP !!! I re-shimmed the Intake and Exhaust valve clearances and it still won't turn over with the e-starter. The Starter is clean (disassembled and checked) and the Exhaust valve clearance is now .011". Still a little wide by .003" but if i went with the next size (235mm) shim it would be too far closed by .002" so what the hell ?

The ADC seems to work ok.. it pivots and clicks the valve open as it should. Could the ADC can be too far worn to open the valve ? Im stumped… Any ideas are more than welcome.. I need to get her working for the Desert 100 in April .!!
Click to expand...


Have the cams been out of this bike? Was the elec start working and then it stopped working? When did it stop working? Was there any work done on the bike and then the elec starter stopped working?
 
It was running fine one after noon when it started to die on me.. then it just completely died couldn't bump it nothing I let it cool of and it started then again quit and locked up like something in the ADC failed.. checked the ADC and valve clearance did the re-shim and it looks good. Possibly the ADC cam lobe is bad or the Exhaust cam lobe is out of tolerance.. I didn't measure it.. thats next i guess…
 
After reading a bunch of forms on the ADC, I'm gonna go ahead and replace mine. I am betting the ADC lobe just wore down and it finally got to the point it just doesn't open the Exh valve enough to release any pressure. Now, how hard is it to replace? Anyone know if there's a trick to pulling the cam bearing?
 
When you pull the cam, look at the rocker arm and use you finger to feel if there is a groove in it, and feel of the other exhaust rocker arm. I thought about swapping out the 2 exhaust rocker arms.
 
Ok, Still no joy…. I replaced the ADC cam and put it all back together and still no way the E-Starter can turn it over.. Its close but its just too much compression.. I checked the Exhaust valve gap again and now its .011" and .010".. Still over the recommended .008" max so now I'm back to shimming to the next larger shim.. the 2.35mm if that dosen't do.. I'm really stumped...
 
OlderHuskyRider said:
You might wanna check your starter brushes. I had the same problem as you and I spent $100 fixing the ADC and then I discovered it was my starter.
Click to expand...

I pulled the starter and disassembled.. Its clean and looked good.. I burnished the stators with some emery cloth and re-assembled..
 
The starter still has real problems spinning the motor even with the new ADC cam. It will do it but its struggling and real slow.. I'm thinking of pulling the head now and checking the valves.. If one of the valve seats has carbon buildup or something it might explain the lack of opening. I have already shimmed the exhaust valves closed .010" each and it still isn't enough... ???
 
Shotgun Jimmy said:
The starter still has real problems spinning the motor even with the new ADC cam. It will do it but its struggling and real slow.. I'm thinking of pulling the head now and checking the valves.. If one of the valve seats has carbon buildup or something it might explain the lack of opening. I have already shimmed the exhaust valves closed .010" each and it still isn't enough... ???
Click to expand...


Have you checked the things I suggested in my thread?
 
Shotgun Jimmy said:
The starter still has real problems spinning the motor even with the new ADC cam. It will do it but its struggling and real slow.. I'm thinking of pulling the head now and checking the valves.. If one of the valve seats has carbon buildup or something it might explain the lack of opening. I have already shimmed the exhaust valves closed .010" each and it still isn't enough... ???
Click to expand...

.010 inches is way too big, the exhaust valves should be at .006 - .008
 
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