• Husqvarna Motorcycles Made In Sweden - About 1988 and older

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 The previous version was outdated and no longer supported.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

The 390 won't start

Thanks for the info Peter. Yes, I realise that I did not describe the timing settings correctly. The 21.8mm setting is shown in the manual and is the distance you should turn the rotor back from TDC to set the timing. By turning the rotor back this far, the piston ends up in the right spot (2.18 mm BTDC from memory, pretty much the same as you state above.) I have now returned the timing to this setting, although there seem to be many posts from lots of people who have retarded the ignition slightly on the big bore engines, resulting in easier starting, and this is what I was hoping would happen.

I am away all next week, but by the following weekend I hope to have more idea of what the problem is.
 
heres a easy way to set your timing..
remove the sparkplug, and flywheel cover,
put a long screwdriver down the hole with one hand, and turn the flywheel with the other hand,
youll notice that as the the piston reaches TDC you have an arc...were the crank still moves, as the piston doesnt.
set the timing at the start of the arc..just as the piston hits TDC.. the timing marks are lined up by a small hole in the flywheel that meets a hole in the stator...use a long allen wrench that will fit inside the hole..
 
Well I won't be on the 390 for a while yet!
cry.gif


I ended up stripping the top end of the motor and basically it is knackered (that's old English for in a complete mess). The grit they used to clean it up hasn't been washed out and so it has scored up the bore again and now got low compression. I dread to think what else has been damaged by the grit, plus the guy who rebuilt it has bodged the base gasket.

It appears he has used three layers of gasket paper and used silicon to stick them together, then the silicon has oozed out when the barrel was bolted down and it has then blocked up the transfer ports, which is why no fuel was present on the plug. I can't believe it really, because I gave the motor to a reputable builder who I will not name as I have not yet spoken to him about this and it was not a cheap rebuild (480 pounds). I will be speaking to him next week and will be expecting a full rebuild free of charge or maybe even a replacement engine if this one is beyond repair. I can only think he gave the engine to someone else to rebuild and this person has screwed up basically.
mad.gif


I am really pleased I didn't sell the 125 so at least I can ride that for now. Will let you know the outcome.
 
Sorry to hear about your troubles. Alot of wanna be mechanics out there should give things a bad name. Rick Lago at Motocentre in Yakima Washington is a great honest guy. He does alot of Husky and maico engines for the racers around the PNW. I have his contact info if wanted or just Google Motocentre. Sorryabout your luck with that guy.
 
wow....id avoid giving that guy a briggs and stratton....
im sure you can find a real motorcycle wrench if you look, if your in the UK, twin shock Huskys are big,..just look in some of the racer sites and start doing some searching...
beadblast media will ruin your day for sure.,, anytime you use a bead blaster on any ingine parts they should be blown out or washed, or both....that stuff gets in weird places,,,and comes out at the worst times.
 
Well, the guy who rebuilt the engine has acknowledged that it was not up to his usual standards and has taken it back for a full rebuild free of charge. I have every confidence it will be done properly this time and hopefully this will sort out the starting problem. I will be getting the engine back on April 10th so will update you once I have got the bike back together.
 
Well, at last she is running.
banana.gif
The motor was rebuilt properly this time. Rebore, new piston, fully cleaned out bottom end etc and after a bit of effort, she has at last fired up. Racing tomorrow for the first time, so will let you know how we get on. Hope to get a few pics from the meeting.

Hopefully the jetting is about right, although I think she sounds perhaps a bit hunty at the bottom, maybe a tiny bit lean, so I will take a few jets and have a play. The carb is off an 84 CR250 and the jets installed are the standard sizes from the 390 manual. I will have a look at the jetting for the 250 engine and see how it compares, but otherwise she revs cleanly enough.
 
Well, the day started very promisingly. Managed to start the 390 on the kicker, which amazed me, and practice went ok. I was taking it quite steady as this was the first ride on the bike and I have been riding a 125 for the last 2 seasons, so it's completely different.

Race 1 also went quite well, a poor start but early days yet. Managed to pass a few riders but finished well down as I expected. The bike felt great, motor pulls like a train compared to the 125. Definitely not jetted right yet. Still a bit hunty at lower revs. By this I mean it seems to just races a little with small throttle openings, maybe as if it has a small airleak, but it is fine in the middle, so maybe the 45 pilot is a bit lean. Any other thoughts from anyone on that?
confused.gif


Currently running a 430 main as stated in the manual, but not sure yet if that is right or not. Haven't really run it at full throttle, but the engine is fine at mid throttle, really pulls well.

Second race is when it all went pear shaped. Could not start her up at all. Tried bumping, kicking, new plugs old plugs. The plug was just getting wet all the time and eventually I gave up. I am wondering if the Motoplat just hasn't got a strong enough spark to reliably start her up. The kickstart engaging position is also not right, so I will have a look at that first. It isn't providing a full swing, it engages about half way down through it's travel so that is making kicking her very difficult. But she should have started with the push, and that is why I am thinking electrics again.

But the day wasn't a complete disaster. I now know that the bike runs an certainly has great potential. Just need to iron out the bugs and she will be a rocket ship.
 
Have now sorted out the kickstart engaging problem.
smile.gif
Stripped mechanism down and worked out the best position so that it now engages almost right at the top of it's travel. Tested for a spark by pushing the kicker by hand and got a great big fat spark, looks much better now I am turning the engine over properly. It is too late to try starting it up now, so will have another go tomorrow and let you know.
 
Still not starting easily, even with the fuller kick start travel. Ran briefly then spluttered and died. Sparks are good, I am convinced it is carb related, so I have taken the plunge and ordered a new 38 mm VM Mikuni with suitable jetting.

I have another question. Transmission oil. I have read so many opinions on what is the correct stuff to use. I am currently using standard 10/40 engine oil and after reading lots of info on this I am not sure if this is a good idea. General concensus is that this type of oil can cause the clutch to slip. Any suggestions welcome.
 
Murph said:
Still not starting easily, even with the fuller kick start travel. Ran briefly then spluttered and died. Sparks are good, I am convinced it is carb related, so I have taken the plunge and ordered a new 38 mm VM Mikuni with suitable jetting.

I have another question. Transmission oil. I have read so many opinions on what is the correct stuff to use. I am currently using standard 10/40 engine oil and after reading lots of info on this I am not sure if this is a good idea. General concensus is that this type of oil can cause the clutch to slip. Any suggestions welcome.
Click to expand...
Look at your kill switch as this seems to be a problem area with these old Huskys, my buddy has had all the same symptoms you have with starting and we disconnected the kill switch and all the problems went away. Ive had the same with my CR250 and the same thing Kill switch.As for Transmission oil the book calls for straight 20 Wt. but try to find that on the shelf!! I'm using Rotella 15-40 and that seems to work pretty well.
Bill
 
Murph said:
Still not starting easily, even with the fuller kick start travel. Ran briefly then spluttered and died. Sparks are good, I am convinced it is carb related, so I have taken the plunge and ordered a new 38 mm VM Mikuni with suitable jetting.

I have another question. Transmission oil. I have read so many opinions on what is the correct stuff to use. I am currently using standard 10/40 engine oil and after reading lots of info on this I am not sure if this is a good idea. General concensus is that this type of oil can cause the clutch to slip. Any suggestions welcome.
Click to expand...

Spark plug- make sure its a non-resistor, B8ES or B8EG NGK. I gap my plugs at .018 max. It helps starting as it doesn't need so much coil saturation to jump that gap. It also advances the ignition timing a little. The running briefly and died I would look to make sure you dont have a crankcase thats overloaded with gas.
 
Husq.fleet said:
Spark plug- make sure its a non-resistor, B8ES or B8EG NGK. I gap my plugs at .018 max. It helps starting as it doesn't need so much coil saturation to jump that gap. It also advances the ignition timing a little. The running briefly and died I would look to make sure you dont have a crankcase thats overloaded with gas.
Click to expand...

Thanks for the suggestions. I have run it with a B8ES and a B8EG, and it has run with both plugs. The plug cap is a non-resistor NGK. I have set the gap to 0.018 based on your advice from a previous thread, and the spark is good. You may be right about the crankcase filling with fuel, so can you suggest any way of getting it out without turning the engine upside down? With the fuel off is it enough just to turn the engine over a load of times with the kicker to force the fuel out?
 
I have used a air suction gun to basically "vacuum" out the crankcase as I can't tip my bike upside down. Pulled carb and reed cage off, went down into crankcase that way. On my big bores, I actually drill and tap a 1/16" NPT plug in the crankcase to be able to clear the crankcase if needed. Best to do it with cases split.
 
Husq.fleet said:
The running briefly and died I would look to make sure you dont have a crankcase thats overloaded with gas.
Click to expand...

Well, you were absolutely right, the cases were full of fuel. I managed to get it out by turning the bike upside down and with the new carb fitted, she fired up fine, and sounded a lot better.

However, whilst tweaking the airscrew she died and then would not fire up again. She has filled up the cases again and I can get the bike to fire up briefly then it splutters and dies.
banghead.gif


I am losing the will to live and am so close right now to selling the damn thing. Do you know the cause of this problem? It is baffling me. Why should the cases fill up so quickly making it then impossible to get the bike to run?

The new carb has the following settings:

Slide 2.5 Would a 3.0 slide make that much difference? I went for the 2.5 to be on the slightly richer safe side.
Main 390
Pilot 45 Could this jet be too big causing the problem?
Needle is a 6F15 (I think this is the number)
Needle jet Q8

Any suggestions before I throw in the towel for good and go back to YZs for good?
excuseme.gif
 
Murph, deep breath! or two. I think your carb base setting are good other than the slide. I have better luck with 3.0's. First thing I would make sure of, silencer now all saturated and plugged? Clear the crankcase out-again. Start with the slide all the way down, idle screw out, turn in one turn. This will ensure you are only "pulling fuel" from pilot jet. Set airscrew at 2 turns and fire it up and run it until its warmed up before making any adjustments. You cant hold throttle more open to keep it running then adjust idle speed later. Just my 2cents. I went through the same thing with my 83 500XC, one extra drop of gas in the crankcase and it wouldn't fire. It had reeds that weren't sealing and low compression.
 
I'd check the float levels and make sure there's no holes the floats.Check the needle valve to make sure its sealing.
 
Thanks again guys, I think I have calmed down a bit.
cool.gif
I thought about the reeds because I haven't changed them as they look ok. I am struggling a little to think of a reason why the reeds should be the cause of this problem, surely all they do is let the fuel in? They have nothing to do with the amount of fuel getting in, right?

The carb is brand new, and I must admit I have not checked the float height, but according to the website of the supplier Allens Performance, the float height for this carb is 18mm, which is the height recommended in the 390 manual.

I am running out of time for my next race, which is on Sunday, and I am losing faith in the bike. I don't want to be let down by the bike again, so I will get the YZ ready and ride that. I will have to summon the enthusiasm to try emptying the motor out again and see if I can get it running a bit better. My Dad helped me turn it over today, but he is going to South Africa tomorrow for a couple of weeks, so the only way I am going to do this on my own is by taking the whole motor out. Oh joy!
rolleyes.gif
 
Well, a quick update. The suggestion to check float levels was spot on. They were set at 13 mm instead of 18 mm, allowing the floats to be a lot higher, hence loads more fuel in the float chamber. I have now adjusted this correctly and will try the bike again later today. I was certain the carb would have been supplied with the float set at 18 mm, so hadn't checked this, live and learn. Hopefully this will sort out the flooding problem.
 
You must log in or register to reply here.
Back
Top