help on xc500 1985 / OR 390 1978

sorry to post a thread with two different bikes but i think they may have simalar problems,i need to restore my faith in my huskys, i have always loved and adored huskys i purchased 2x a xc500 1985 and a or390 1978 they were imports from California (to UK) I have modistly restored them so i can have a good blast now and then .... but they are a total b*tch to start and it is taking the fun away from my love for huskys and riding... could it be my jetting setting are incorrect for my country?thus making hard stating of them both?both have fuel spark and compression please help.

while yes, jetting can be an issue, and something you should do some research on,,what jets for your alt, ect.
i have found that with the bigger bore 2 strokes flywheel timing is a issue with starting.
its should be set, just as it says in the book..and some racers, restores like to advance it a bit thinking they will make the bike a bit faster.
another issue on the older huskys...is the intake spigout, were the carb slips into, a lot of times they crack easy, and suck air and make them hard to start, and hard to get to idle.
just push on the carb a bit, if you see cracks,,replace it, its a easy part to find, and is available through Ebay or other restoration parts suppliers, for about 25.00 US.

i think i can find something on timing my 390 but cannot locate anything on my 500 anywhere,cheers UK dave.

I'll track it down, I have it at work but from memory I think its 2mm before TDC but I will verify.

both are the same..
there is a hole in the flywheel, that mates up with a hole in the stator,
that should be at TDC..
the Husky 2 stroke timing is the same from 125 to 500 CC..
use a large paper clip straightened out to mate the holes up.

I think the guys at the Husky Importers (back in 85 when I bought mine) set the timing to 1.5mm which they said stops any nasty kick backs and makes it easier to start..... I hope to find out soon again as my engine hasn't been fired up since '87... I think.

Stu

Good to know!!

I think there might be a service bulletin on the 500's from around that time frame on a ignition timing change. 84/85/86 ????

HD you are right with the 2.2mm BTDC. I found my service bulletin dated 2-20-86. I had my 87-430XC @ 2.2mm and it kicked back hard enough to make be hobble for a couple of days. Set it to 2.0mm and life was better. As I refresh mine they are going to have decompression valves before another case gets broke.

those updates are the ones everyone was trying..yes, they give you a bit of power, but make the bike hard to start, and it will hurt you...
my sugestion was TDC, as stated in the Husqvarna service manual, i set mine at the start of the crest, just as it hits TDC.
and with an old 450 cc with a 5 inch kickstart lever, its makes them much easier to start.
the 500Auto i used to have was set a 2.2MM before TDC, and was a bear to start, i reset it at TDC, and it was a dream to start..
one thing you want to check..if you have a Motocross style stator, with the flywheel inside the stator, instead of the regular outside heavy flywheel, you going to just have a hard to start bike, no matter what you do,
the internal flywheels didnt have enough weight to keep the Engine spinning over during start up on the 500cc bikes.
i also learned this the hard way..switch it over to the WR or XC type set up, and youll be happy as a clam.

I have chased the big bore Husky starting problem for many months. It should start in 3 or 4 kicks hot or cold ( usually the 2nd good kick).

The ignition must be grounded very well. Clean the motor mounts and the coil mounts from any paint or corrosion. Also clean the bolts where the stator mounts to the engine cases ( you can do this without removing the flywheel).

Next check the timing. Mine was advanced ( it ran perfectly once it started, but was a bear to start sometimes). It should be set at 2.2mm BTDC. Also set the plug gap to 18-20 thousanths. I retarded the timing just a little and it will light off easily now.

Just to add my experience, After a few years of riding the 83xc500 I found a "deal" on an 85-86 xc500. The guy I got it from could start it fine, I could start my air cooled one fine with either leg but never could start the water cooled one. I spoke with the dealer, a one man shop AA level rider and he said something about the ring not sure by now exactly what he said. Later on I got another "deal" on an 85-86 xc500 but was told it was an 87. I could actually start that one but disassembled it anyway and put the engine into service as an air cooled easier to start for me. Lately I have had better luck finding mahle pistons for the 500 models and may well be able to try out a water cooled 500 with a fresh ring in the bore and see if what the dealer was telling me agrees with my findings.

I also don't believe with the 10 pound weight and diameter of the crankshaft assembly changing the ignition components will have much effect at all on the rotational mass of the engine. Believe what you want.

inside flywheel stators have basicly no weight,,if the weighted mass wasnt an issue....
then why are so many companys selling weighted flywheels to ad lower torque to a 2 stroke..just look at any trials bike..
the kickstart lever on my Beta is less then 5 inches long, with a highcomp piston 270CC 2 stroke..without a heavy flywheel id never be able to start the thing.
simple weight vs mass comes to mind...think about it...
if you spun a shaft with a ten pound weight on one end vs a shaft with no weight, wich one is going to keep spinning longer???hmmmmmmmm.

This seems to be a dear subject to many of you, and me too actually
What I understand of what I've been reading was the advance 2,8mm for the 83 and 84 500cc.
Different recommendations says to lower the advance to 2,2mm to prevent the nasty kick backs from the big bore two strokers.
I've seen this recommendation in several forums and threads.
But it seems to me as it would be a good idea to lower it some more after reading your posts in this thread, correct?
I hurt myself too many times trying to start big bores

As strange as it sounds--- set the timing per specs, then back it off a little at a time until it starts good. Then ride test for performance.

hi there after many days of doing this kicking doing that re-kicking , my problem on the 500 was very simple and embarrasing but may be good inspiration for others ..... check the basics ! ... as i was going down the timing route removing the flywheel i discovered some of the pick up points on the rotor were rusty , cleaned them up chucked t flywheel back on.... got a massive spark more than before and i am now in the 1-2 kicks club yeah .... i am so happy and have feel back in love with huskys..... now for the 390-.....

Yeah,

Not sure about your terms rotor and flywheel are the same aren't they. Stator is the part which stays put, Just out of curiosity did you also change the spark plug? I had this strange thing happen with my husqvarna chain saw lately. I didn't have hardly any spark it seemed to work if I left it in the sun for half a day. I tried things like hanging the coil with the pick ups over the furnace over night, polishing and re shimming it. The spark plug made great spark when put into the kawasaki engined gasoline air compressor spark plug wire. Saw ran fine and had good spark with a new plug. Strange.

Fran

More great info for a newer first time Husky owner.

Good info, thanks! Can not wait to get home and check mine for rust.