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 The previous version was outdated and no longer supported.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

Replaced my 1.1mm head gasket with a 1.2mm, now bike won't idle

OlderHuskyRider

OlderHuskyRider

Husqvarna
Pro Class
For 2 years, the bike has idled at 1900 on the button, with very little change in the idle screw. As I buttoned up the bike, I shimmed the exhaust valves a little looser, right at the middle of the spec, they were a little tight. Bike has always run great in the middle of the spec.

Bike started up and idled a little low at 1700 but I thought, hey, it'll get better, it dropped to 1600 pretty quick and I reached down to try and get it higher, the idle screw would not get it any higher, it started getting lower, I said heck, I'll ride and get it hot. I rode it and at the first light it got so low it died. I rode home and had to keep it above 2000-2500, it ran so bad below that, but above that it ran great.

The only thing I thought of was tight valves, so I took the cover off and checked them warm, still right in the middle of spec.

I'm prepared to shim the valve sloppy loose if that's what it takes.

But I feel like there's something else that I may have inadvertently changed and don't realize it.

I don't have ibeat and have never messed with the TPS and don't really want to start now, I feel like I can get the bike back to where it was somehow.

Looking for ideas on why my idle gets lower and lower as the bike gets hotter and hotter.

Could the temp sensor be bad and the ECU keeps feeding it enrichment even tho its getting hotter?
 
Ok so once again I am a car guy and know nothing of modern bikes FI system- but some dodges as well as others require a relearn drive cycle procedure to learn where there at, it takes longer than you think, and will make you think you have screwed something up. You may want to unplug battery both sides,while unplugged touch neg and pos together this will fully discharge system then run it on the stand- hold at 2000-2500 rpm and then let it try to find idle it wont work the first dozen times or so if it is like a early car system-try not too let it die all the way out and repeat cycle, thats the old school way of resetting adapitives if you dont have a scan tool to do it for you, one last thing and then I am done my bike does not have a fan I dont know abou yours so you may have to be careful of overheat situation.
 
Thanks Kam, that's something I can try in the morning after I button it back up. I'm gonna leave the valves where they are, they aren't tight and it's run good before so....

Yeah, i have a floor fan I put down in front of the bike for stuff like this, it wont over heat for sure.

I may even try to adjust the throttle stop screw to get it back up to 2000 idle.
 
Perhaps experimenting with doing the procedure kam listed with the air idle screw turned down some? If it finds sort of steady idle, then you will have some adjustment left on it. Could totally be talking out my butt, but heck I'd try it.
 
Here's what I am chasing now, I find what I think is a partial grounding of my Green with red stripe wire. This wire connects the relay, the fuel injector, the fuel pump, and the coil. When I put a test light on any of this wire's terminals, I get a faint little glow on the test light bulb, with the light being grounded to the frame. The relay and fuel pump are unhooked for this test. Is a partial ground ever acceptable or should I start hunting this down. Bike runs great at higher RPMs, but below 2000 and without throttle blips, it will eventually die down to nothing.


UPDATE:

I had unplugged the fuel pump and the relay to take those items out of the mix, but I had not unplugged the injector, wow, unplugged the injector and the partial ground went away, plugged it back in and the light came back on. Is this normal from a electrical standpoint or should it be completely not-grounded?

UPDATE:

I took the injector off the bike.
There is no continuity/grounding between the 2 injector connectors on the harness.
There is no continuity/grounding between the 2 prongs of the injector itself.
There is no continuity/grounding between the body of the injector and either of the 2 injector prongs.

Yet, when the injector is plugged into the harness, there is a tiny grounding on the Green with red stripe wire which is the fused/relayed power wire.
HuskyPartialGround_zps5d304f55.jpg
 
Head gasket difference will not make any difference in regards to idle fluctuations.
Gasoline will tho with the varing amounts of BS addatives that are now put into it.
Sounds like need it put on I beat and reset the TPS
Later George
 
Up-tite said:
Head gasket difference will not make any difference in regards to idle fluctuations.
Gasoline will tho with the varing amounts of BS addatives that are now put into it.
Sounds like need it put on I beat and reset the TPS
Later George
Click to expand...

Thanks for your input George, always good to see ya around, did you see the shot of your skid plate in action....

UDSfeb2013e_zps5fc0c36c.jpg
 
Hmm, so the harness is grounded when both the relay and injector are disconnected?

That doesn't sound right. If it ran good before and haven't messed with anything else it's not likely your fi system suddenly got all lost on you. I would guess the issue is somewhere in a voltage drop and a chaffed wire perhaps.
 
Huskynoobee said:
Hmm, so the harness is grounded when both the relay and injector are disconnected?

That doesn't sound right. If it ran good before and haven't messed with anything else it's not likely your fi system suddenly got all lost on you. I would guess the issue is somewhere in a voltage drop and a chaffed wire perhaps.
Click to expand...

The Green with red stripe wire was showing to be slightly grounded to the frame WHEN the injector was plugged in, the grounding went away with the injector unplugged.I may have gotten rid of that by replacing the connector on the fuel injector, but the bike is still not idling. I turned the idle up with the throttle stop screw and took a ride, idling 2000-2250 RPM, but when I pulled into the garage, and let it idle by itself, it just kept getting lower and lower and lower and finally died. Very disconcerting.
 
I guess what I am looking for is any input on what parameters would make the bike idle worse and worse the hotter it gets. First thing to my mind is the WTS, that maybe it's sending bad data to the ECU and the bike is choking to death because the ECU won't lean out the mixture as the bike gets hotter. I let the bike idle until the water temp was 210 and bam the fan came on like clockwork, just like always, so I am thinking it's not the temp sensor.
 
motosportz mike said:
Let me know if you would like to try to reset the TPS, I have an I-beat set up I could let you use.
Click to expand...

Thanks for the offer Mike, but I believe it is something quasi-mechanical that is causing this, like the partial gounding of the Green with red stripe wire.

I was thinking maybe the temp sensor was bad and the bike was continuing to run rich, but I pulled the plug and it was not black and not carboned up after dying out hot. The plug looked great.

So now I am thinking, as the bike gets hotter and the ECU leans out the mix, MAYBE I have low fuel pressure problem, the bike is not getting enough fuel to run at idle.

So a question here: would a failing/low pressure fuel pump run good at speed/higher RPMs but not run good below 2000 RPM and not idle well?

Similar question: would a partially grounded fuel pump power wire run good at speed but not idle well?
 
I borrowed a fuel pressure tester from the auto store, my 2 year old after-market 38mm pump tested at 55 lbs right out of the top of the pump, and then tested thru the $5 fuel filter and the pressure regulator, 45 lbs. That's off the bike with an old battery I use for the weed whacker. Now, I just need to make sure I am getting full voltage to the fuel pump, and coil and fuel injector (all 3 are on the same wire) while everything is on the bike.

To test if I am getting full voltage to the Green with red stripe wire, do I connect one multimeter probe to the wire and the other one goes..where?
 
at the time when my smr450 09 was new, he reacted poorly to the screw idle and very difficult to start engine. But there were all the signs of a lean mix and I found the reason for this rather quickly. There was deformed surface under the air filter.
 
mr.Skin said:
at the time when my smr450 09 was new, he reacted poorly to the screw idle and very difficult to start engine. But there were all the signs of a lean mix and I found the reason for this rather quickly. There was deformed surface under the air filter.
Click to expand...

I am running a foam filter which is wide open, I don't think any extra air coming thru the air cleaner area could be possible. Were you running the OEM filter cover, that plastic snorkel thing?
 
Well, I tested the fuel pump, spent a few hours just going over all the wiring under the tank, especially the Green with red stripe wire, put the OEM connector back on the fuel injector, buttoned it all back up and same behavior: starts fine, idles rough at 1700 instead of smooth at 1900, gets progressively worse, down to 1600, 1500 and at 1400 it starts snatching the clutch and transmission and I shut it off. Wait 10 minutes, and starts good at 1700 RPM and then goes downhill.

OlderHuskyRider said:
Similar question: would a partially grounded fuel pump power wire run good at speed but not idle well?
Click to expand...

Also, now the Green with red stripe wire shows to be completely grounded with almost zero resistance and fully bright test light bulb. So before, it was just barely grounded, now it's fully grounded. It's why me and electricity don't get along, it claims to be logical and claim it's not....
 
I had a thought that maybe I was one tooth off on the cam drive sprocket versus TDC, like maybe it moved a little when I was installing the drive sprocket, but everything there looked normal. I did move the intake cam one tooth, looks like it matches the exhaust cam for angle now, but the dimple dot on the left side is way off from where I've always set it. Bike exhibits the same behavior, wont idle for long.

I'm thinking I have a cam timing issue somehow, my marks are all way off, things seem real weird, tomorrow is the 7th day since I tore it down for a damn head gasket swap.
 
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