390 not ticking over

got the bike running and noticed before the jets where not standard,so replaced to standard jets and fitted boysen reeds,will not tick over on its own. throttle stop wound allway in and mixture screw 1.5 out so changed to 50 pilot but still only just tick over again with throttle stop wound allway in-anything im missing ? bit lumpy spluttery first quater throttle stripped and cleaned carb twice mmm any info guys

35 pilot, 400 main,

will try

it did have 35 pilot in it and i think 360 main but trhought i would put it back to tandard and give it a try,do you think maybe too much fuel ?

better

well guys whent back to 35 pilot and 360 main lots better ticks over but still bit spluttery up to 1/4 throttle

all day on her

well guys spent all day fiddling,will only tick over with iddle screw nearly all way in but runs great otherwise havnt got excesive smoke or drooling oil after quarter throttle she goes like a train mentaly quick,just first start off in first gear bit spluttery am i running on mainjet by having idle screw so far in is pilot circuit still blocked? any info would be appreciated cheers.

whats your elevation?

sea

sea level ish

I would look at your slide cutout. If your having to raise the slide to keep it running or idle my suggestion is to go to a higher # slide cutout. This allows more air in the way of velocity to pass through the carb allowing more ventury effect= stronger pull of fuel through pilot circuit. This also allows the slide to be lower allowing the pilot circuit to actually work. You are probably "past" the pilot circuit in slide height and running off of the main circuit, pilot is always a factor but majority is coming from the main. I always start with a 3.0 slide and have modified them to probably a 5.0 to obtain best tuneability from idle screw. Goal is having slide shut as far as possible and have the most adjustment range of the idle screw. This will "clean up" your idle, mid-range. There was a thread with some great pics of slide modifications awile back, I think Husky T posted them if your searching. Scott

yep

this is pretty much what i thought,as the mixture screw doesnt seem to have a great deal of affect,and im running on jn instead of pilot circuit its on first overbore boysen reeds and circle f exhaust all within spec but ime asuming timing is correct would this factor as it runs fine with open throttle ? would it be worth removing carb again an re checking pilot circuit ?i did go up one clip on the neddle and this seemed to make a diference any info would be appreciated

sea level, id try a 400 main..leave your pilot alone,
set yoru needle in the middle, and adjust from that point...hard to say without hearing it run...make sure your runing a B8ES blug...maybe a 7
stock jetting was 440 i belive, and set fat for break in.

I have specs from my 80 OR390, stock Main-430, 45 pilot, R-2 needle jet, 2.0 slide but doesn't say which needle. I'll dig and see what was changed in my carb-if I can find it? I went to the 420 "kit" with mine and desert raced it, never a hint of siezure when 390 or 420'd. I know we probably cut the slide to a 3.0 or 3.5 spec. The shop here usually did that at assembly because they were so "fat" at idle at this elevation, 1200ft and most headed right for the hills, up to 4000ft. My 390 and other big bores Ive had always needed some warm upriding before they would clean up past 1/2 throttle. My "mixed gas mentor" said that was a safe tune. Probably went through more gas than most but never have siezed a Husky owned since 80! Now probably next ride.......

There is a Husky bulletin maybe on this site that has the race mods for a 390 and the 420 upfit instructions. Might look at those being you are "piped". I raise the needle one clip and go up 10 on the main on mine when putting a pipe on for something to start with, just a thought.

ok

clip at mo is fourth notch from bottom,and a 360 main that was in it.but i thought the main and neddle dont come into play untill after 1/4 throttle as its up to 1/8 throttle i have the issue, will try bigger main and see what happens,yep running a b8 plug did try running iridium plug but it foulled that slight carbon/sooty so running way too rich yes ? any info is good carbs are my archiles heel so really would like to get my head around this,there isnt excessive smoke have little oil deposit from header but not much when i lifled clip position it seemed to run crisper and lot zingier if that makes sence cheers guys.it is lott better than it was so im doing something right just little hesitant on take of then goes awsome.surely bigger main and lower clip is going to make it run richer ? in between 1/4-full throttle and full.i havnt had her full throttle yet as i havnt got a big enough field near by lol was trying to rectify one issue at a time.but open to any input cheers,allso guys my plug is at .024 is that about right?

update-ran her this morning moved clip to top ran lots better hardly any hesitation from sandstill up to quarter moved idle screw out slightly so not competely allway in but still not right not far though-then checked for any air leaks and noticed mating surface between head and barell bubling have lapped this in before could this be my starting idle issue? any tips guys to stopping this leak have lapped it in before certainly not going to help issues is it

I run .018 plug gap, less coil saturation time to jump the gap and I feel it stays cleaner. Was your iridium a resistor plug? In the states thats all you can buy now. Never been big on the precious metal plugs as they are more for longevity in wear than a "hotter spark". I run a B8EG in all of mine, its a NGK race plug, fine nickle electrode, works flawless for me. I would set the carb to stock specs to start with and work on the primary circuit. That way you know your safe on the upper end. What air jet if any does yours have? That would effect the pilot circuit also. Air jet is what is metering the air before the idle air/fuel screw. That adjustment effects the "signal" to teh pilot circuit. Increasing the cutout of the slide also does somewhat the same. Increasing the velocity/amount of air passing over the pilot is the venturi effect, think of holding a bottle full of water out the window of your car, faster you go the venturi effect pulls water out of the bottle into the air stream. Air jet and idle mixture screw would be a another aid to put the liquid into the air stream. I dont grind my slide all the way across as some pics show, I will start with a concave in the middle of the slide cutout and increase that untill I'm satisfied. I believe that concave further directs the air over the pilot and its concentrated in that area to further improve the signal. What we easily forget is? A gasoline engines output is regulated by its air input, we open the throttle to increase output. That greater throttle opening then allows more air into the engine. Venturi effect in the carb. then pulls more fuel into the air stream for combustion=output. Sorry to get long winded......Scott

On the cylinder head sealing, my old trusty 84 WR250 woods bike has always done that when cold, seals up fine when warmed up. It doesnt look anything like your bike so the "drool" isnt an issue with it! I would find the non-sealing place with something like blue valve/gear marking compound. Apply a very thin film, torque head down and remove and see where its not sealing and determine why.

Found my 420 spec.

Here are the carb specs I had for my 80-390/420. Stock is on the left, right side is what I ran

Main-430/440
Needle Jet-R2
Needle-6DH-3/ clip in middle
Pilot-45/42 after slide modification
Slide-2.0/ cut to 3.0-3.5
Air jet-2.0

You might look at your needle as you didn't state what it was. The 390 carb specs from the parts manual in my previous post didn't state a needle number. Hope this helps.

right

removed head and barell spent lot of time relapping head and getting it just perfect was small imperfection managed to get thet out,re sealed all inlet gaskets and exhaust,re cleaned and checked carb all clear, pilot is 35 with 40 or 45 couldnt get it to idle at all and plug was fouling so asuming it was running way too rich,today got it running pretty good hardly any bog or stumbling but to do that had to have clip on top.will try it again tomorrow see what affect re lapping head has had if any.when i removed the head the piston was quit oily/fuel saturated.will try again tomorrow and keep you informed thanks for help
here is what is in it at mo:
air jet 2.0
main 360
nj 166-r2
slide 2.0
nedlle 6dh3

Worn parts?

Idea only! I have seen needles and needle jets worn to the point they were flowing alot more fuel than stock, just an idea? I would definately start with a 3.0 slide.

thanks

yep will take that into account,if there is no change will look at replacing jn and nj and then slide was thinking of checking compression allthough everything was in spec not enough compression coul have an affect on tick over iddle yes? any one know what it should be thanks for help will keep you updated.

sounds like your close, try a 350 main. and move your needle in the middle, and try again.

nearly there guys

right put neddle clip back to middle 35 pilot back in, idle screw about half turn out from allway in,ticks over runs good revs sweet little oil from exhaust and seam on end can (and header allthough i have sealed it again) air screw/mix 1.5 out but still little bog from standstill not much but little.did try 45 pilot as i didnt have 40 but going out on air screw and revs just kept rising untill allway out,think i may need a 40 pilot.

As revs increase with air screw decrease idle speed with idle screw/slide untill satisfactory idle is obtained between both adjustments. That is a good sign that the air screw increases revs. Then lowering slide to reduce idle speed will help clean up idle and off idle as your utilizing more of the pilot circuit! Sounds like your winning