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 The previous version was outdated and no longer supported.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

2007 SMR 510 heat and coolant issues

S

SMR510 Rider

Husqvarna
B Class
A couple weeks back I started up my 510 and it was really hard to start. Finally got it going and let it idle to warm up, per usual. Went to get on and notice coolant squirting out of the reservoir. I immediately feared the worst, a blown head gasket. Dumped the coolant and oil and didn't find any coolant in the oil and vis-versa. I took off the valve cover and noticed that the clearances on all the valves were completely tight. Did a Cylinder Leak Down test and found it was leaking into the exhaust and intake. I adjusted the valves and had to go from a 2.35 to a 2.25 shim on the intake and a 2.25 to a 2.15 on the exhaust. All four were worn the same. I know I checked less than 2000 km ago and they hadn't moved for 4000 km since the last rebuild, so I got a bit lazy.

I put the cams back in and did my best in lining up the timing marks. I know the piston is dead on with the main cam gear. With the intake and exhaust cams, they have a little mark to line them up. Trouble is, when the head is on the bike, you can't see the marks clearly. I'm not sure you could see them clearly on a bench. Did a cylinder leak down test and found it was sealing extremely well. Virtually no leakage with 100 psi going through it. The oil screens were super clean, almost like I'd done an oil change yesterday and it's been 800 km. Nothing on the drain plug magnet. Checked the tensioners and everything looks great.

Put everything back together and did another leak test, good result. Put coolant in it and fired it up. Took it around the block. Runs good. When I pulled back in I noticed that the exhaust pipes were glowing red after a 6 minute ride. I'm not sure if that's normal. Adjusted the carb, checked coolant levels, and took it out again. This time about a 3 minute ride. The fan came on. Now I had the water pump off it and all is good in that department. Brand new coolant. The spark plug is a nice brown color, so I don't think it's lean. First, is it running too hot? Second, if so, why? I've ordered a temp sensor but it's on back order.
 
Sounds normal to me. The glowing pipes is normal if it was getting dark or in a garage. They do that on all modern thumpers. I would check your rad cap seal or get a new cap. The temp sensor will be nice but i think you are ok. I run my 08 tc510 up to 115C or more in the woods with no fan. I have a higher pressure cap on the rad.
 
SMR510 Rider said:
A couple weeks back I started up my 510 and it was really hard to start. Finally got it going and let it idle to warm up, per usual. Went to get on and notice coolant squirting out of the reservoir. I immediately feared the worst, a blown head gasket. Dumped the coolant and oil and didn't find any coolant in the oil and vis-versa. I took off the valve cover and noticed that the clearances on all the valves were completely tight. Did a Cylinder Leak Down test and found it was leaking into the exhaust and intake. I adjusted the valves and had to go from a 2.35 to a 2.25 shim on the intake and a 2.25 to a 2.15 on the exhaust. All four were worn the same. I know I checked less than 2000 km ago and they hadn't moved for 4000 km since the last rebuild, so I got a bit lazy.

I put the cams back in and did my best in lining up the timing marks. I know the piston is dead on with the main cam gear. With the intake and exhaust cams, they have a little mark to line them up. Trouble is, when the head is on the bike, you can't see the marks clearly. I'm not sure you could see them clearly on a bench. Did a cylinder leak down test and found it was sealing extremely well. Virtually no leakage with 100 psi going through it. The oil screens were super clean, almost like I'd done an oil change yesterday and it's been 800 km. Nothing on the drain plug magnet. Checked the tensioners and everything looks great.

Put everything back together and did another leak test, good result. Put coolant in it and fired it up. Took it around the block. Runs good. When I pulled back in I noticed that the exhaust pipes were glowing red after a 6 minute ride. I'm not sure if that's normal. Adjusted the carb, checked coolant levels, and took it out again. This time about a 3 minute ride. The fan came on. Now I had the water pump off it and all is good in that department. Brand new coolant. The spark plug is a nice brown color, so I don't think it's lean. First, is it running too hot? Second, if so, why? I've ordered a temp sensor but it's on back order.
Click to expand...

sounds a bit hot to me. You got a thermostat? is it working? got good coolant flow? clean radiator fins? etc. I guess if coolant was leaking into the overflow tank this might be moot. but hell, it's a couple of simple checks.

what about an air leak or bad manifold? howz the carb?

there have been reports of double & triple-checked cam timings that were actually off by a tooth. I don't have experience with this motor... maybe someone who does will chime in.
 
I had a similar problem with mine. If the coolant level is low and the motor overheats, it will blow steam into the overflow bottle. If the bottle is empty, it will melt a hole in it. I switch to Evans waterless coolant, installed a fan and had no more problems. Prior to this I had the cross-over hose explode on me when it got hot. Scared the hell out of me and was very uncomfortable, but I was lucky I didn't get badly scalded.
 
I do realize I didn't have to pull the cam. I was convinced it was a blown headgasket so I went ahead and pulled the cams off.

Since the post, I pulled the valve cover. I still can't see the timing marks indicated in the manual, even with a mirror, on the exhaust cam. The frame is in the way. I can see the intake makes and they looked good. I noticed that there's a mark on the front of the cam gear that lines up with the edge of the head. The exhaust was off by one tooth, by this measure. So I adjusted one tooth and the bike fires right up. Runs a bit cooler as well. After riding around a few minutes, the exhaust header still glows red at night, just for the first few inches out of the head. I haven't been able to run it for more than a few minutes. I have 5 month old twins, so that's a time sink.

I plan to adjust the carb again and check the spark plug. Everything else should be in order. We'll see. I can't get waterless coolant out here. (I live in Taiwan.) I put a high quality conventional coolant in it and it has a fan. This bike doesn't have a thermostat. I think it'll be fine if the carb is adjusted correctly. A few months ago I went through a huge process, getting the carb adjusted. I found what I thought to be the right needle setting and idle adjustment. The issue I've found is that when I adjust it to run good on engine braking, it doesn't idle great. It sounds like it's running rich. I feel like the optimal adjustment for idling at redlights isn't the same as the optimal adjustment for engine braking. But I think my idle issues lately have been due to the valves.
 
i have yet to have my header pips glow red. sounds like it is way fuckin lean to me. should b jetting specs for a 450 in the threads on here. go through and make sure all jets are clean, carb spic n span. and perhaps s get some help on adjusting your valves.
 
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