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 The previous version was outdated and no longer supported.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

510 runs lean, won't start, doesn't idle

Mehusieni

Mehusieni

Husqvarna
A Class
Decided to do a new thread because this problem seems more severe than I thought. Bike 2008 SMR 510, full power-up kit and zip-tied fuel pump. Had problems with a priming fuel pump but fixed it by sanding the ground connectors.

Thread here: http://www.cafehusky.com/threads/solved-fuel-pump-wont-prime-start-complete-mystery.90085/

The bike worked fine for a day and the next day wouldn't. Engine's just been rebuilt with about 5h on the clock. Starts, doesn't start, doesn't idle, idles for a bit, throttle kills the engine or revs up, it's all completely random.

I've:
Charged the battery
Cleaned the ground connectors again
Checked timing
Checked valve clearances (all in spec except one intake loose by a really small amount)
Checked the intake boot for cracks (I wanted to test it with brake cleaner to see if it was leaking but couldn't get it to idle. Took the EFI off and couldn't see any cracks on the inside and the revs aren't going up and down.
Made sure there isn't an air bubble in the fuel line
Brand new air filter
Changed the battery (This is a weird one. Took the battery off of my KTM and the bike would fire right up. Idles and revs like it used to, other than that small bog right off throttle which I was trying to fix with the iBeat. As the bike warmed up, the iBeat showed engine temp barely at 50 degrees C but the exhaust was glowing red. Never had this happen on this bike after a minute of idling. As I thought the new battery had fixed it, I went to adjust the TPS (warm engine) and again it didn't want to idle or start. Changing the TPS value back to what it was doesn't fix it.

Only ran with TPS at 908 mV/~103.5% WOT
Cold/warm engine has no effect.
Idle screw has no effect.
Changing TPS little or much to either direction has no effect.
There wasn't an impactful change in humidity, temperature or elevation between the two days.

All this from just sitting in the garage overnight...
 
Check air leak at intake manifold.

What thickness head gasket was used? If the original thickness was not used, cam timing will be off.

Cam timing could be off even if instructions were followed. I had my head off numerous times and when my cam timing was off by one tooth, I had the symptoms you are having.
 
OlderHuskyRider said:
Check air leak at intake manifold.

What thickness head gasket was used? If the original thickness was not used, cam timing will be off.

Cam timing could be off even if instructions were followed. I had my head off numerous times and when my cam timing was off by one tooth, I had the symptoms you are having.
Click to expand...
Checked the air boot today with brake cleaner, no leaks.
Oem head gasket was used.
Cam timing is correct 100% (used a marker to make sure the dots align)
Tested 3 different fully charged batteries

Spoke with the guy who sold me the iBeat and he said that it doesn't matter if you use V1.0 or V2.0 of the software in a 2008 bike. 2.0 just has more options for adjustments.

I suggested a clogged up fuel filter and he agreed. Told to me try it without the plastic filter and spray the metallic net filter with brake cleaner so that's what I'm doing tomorrow. I'm 100% sure that the problem is in the fuel system. Either filters or injector. I checked online for generic symptoms of a dirty filter in cars and they mention hard starting, stalling and a smell of gasoline. Exactly the symptoms I've noticed
 
I had in mine Husky like this problem. Very hard to start, when you was get bike to running, no idle etc.. Only to keep it running was turn throttle on/off, flames was coming out the silencer etc..When i was checking from powercommander, then i was see TPS reading is sail up and down, at all times. When driving that bike issue on, was very hard. In that EFI/ITB was TPS sensor broken. If you can see that TPS reading in data stream etc, if that reading is move all the time in idle your TPS sensor is broken. So was you test bike with new fuel filter?? When i was not get the bike working with universal/normal fuel filter never, is need some different. I dont have any pisc what filter would fit in there
 
Mik-3 said:
I had in mine Husky like this problem. Very hard to start, when you was get bike to running, no idle etc.. Only to keep it running was turn throttle on/off, flames was coming out the silencer etc..When i was checking from powercommander, then i was see TPS reading is sail up and down, at all times. When driving that bike issue on, was very hard. In that EFI/ITB was TPS sensor broken. If you can see that TPS reading in data stream etc, if that reading is move all the time in idle your TPS sensor is broken. So was you test bike with new fuel filter?? When i was not get the bike working with universal/normal fuel filter never, is need some different. I dont have any pisc what filter would fit in there
Click to expand...
Yes I tried a new filter and cleaned the strainer. Both were filled with this black gum, kinda like soil. Never did the fuel filter look this bad in my ownership. The junkies who stole it must've put something inside the tank.

After putting in the new filter, the fuel pump primed a bit better than before but the bike wouldn't start. I can hear it prime at a lower psi than it should and fuel isn't even coming out of the tank. Then it wouldn't prime at all. Out of anger, I punched the fuel tank and it started humming. The black gum must've gotten inside the fuel pump and blocked it. Ordered a new quantum pump and a strainer from fuelperformance.co.uk and should arrive next week :3

This is exactly what it sounds like so I'm 99% sure it's the pump that's bad:
View: https://youtu.be/UfLUezWAxGI
 
Mehusieni said:
After putting in the new filter, the fuel pump primed a bit better than before but the bike wouldn't start. I can hear it prime at a lower psi than it should and fuel isn't even coming out of the tank. Then it wouldn't prime at all. Out of anger, I punched the fuel tank and it started humming. The black gum must've gotten inside the fuel pump and blocked it.
Click to expand...


It sound like you say, blocked if fuel is not coming out there
 
Okay so a new pump, filter and a strainer today. Turn the key and nothing... Doesn't prime, doesn't start. Doesn't prime even when I punch the tank. At this point I'm all out of ideas. There are no offroad mechanics in my city. Only thing I could think of is something like a tilt sensor. Something is not getting power or has a bad ground. Got a multimeter today but have no idea what volt or ohm readings I'm suppose to get when checking connectors. The dirty filters + fuel pump was part of the issue but not a fix. How does something this bad happen overnight????
IMG_20190628_011617.jpg
 
R_Little said:
What pump did you buy?

Maybe it is bad?

Check for 12-14v at the pump leads.
Click to expand...

The pump is the quantum fuel pump from fuelperformance.co.uk. I'm not getting any reading from any connector. Resistance or voltage. Can't even tell if the problem is inside the tank or outside it...
 
Don't want to jinx it but I think I finally got it figured out. Since I didn't get any reading on my multi-meter with the new pump, I hooked up a battery directly to the fuel tank wires and this time nothing. Pulled out the pump and the ground wire connector had completely shattered from the pump even though I was very gentle while installing it. Cut the wire and soldered a new connector. Hooked everything up and turning the key fires the pump right up. Primes atleast 5x better than the OEM pump. Are the husky pumps really this bad?

Found a wiring diagram from another forum in which someone highlighted the wires that are in the circuit. I'll post it here when I get the chance in-case somebody has the same problem.
 
Yeah, that's my pic, I checked my earlier post to you and I did not mention grounding, as I usually do, my bad, glad you are sorted.

The line highlighted is the Green with Red stripe wire, incredibly important on these bikes, I had several issues with bare spots on this wire, rubbed raw by the vibrations
 
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