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 The previous version was outdated and no longer supported.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

83 Cr250 Jetting

H

Husky457

Husqvarna
Hello all. Im new to this Forum so before I get started forgive me if I make any mistakes. I am glad I found a place that deals with Husky. I do have a few Husky dirt bikes.

I have an issure with a 83 Cr 250. Hopefully someone out there can point me in the right direction as I've heard many answers but none the same. The bike has good compression, leak down test is good. New gaskets and rubber on intake. Timing is spot on at 2.55 BTC. Carb is a 38mm Mikuni thats as clean as I can get it. Repacked my silencer which is a good thing for everyone to do. My problem is this. Bike starts up on second kick. From zero to 1/8 throttle at load is great. At 1/4 throttle is blurbs ike an old dog, and past that it comes alive and runs great but kinda falls off at WOT. My main jet is a 440, air jet is a 2.0,needle jet is an R4=166, needle is a 6DH20 and Idle jet is a 45. The slide was a 2.5 but went back to stock which is a 2.0. Air screw is out 1 1/4 turns, and The cab still has the old style steel float needle. Air filter is clean and so is the inside of the expansion chamber and there are no mice in it. At 1/4 throttle when im rollen and just give it a bit of choke blubbers more. If I drop the clip on the needle it blubbers more, if I put the clip all the way up, the bike doesnt have juice at WOT. The plug is a NGK B8ES. I was running 32 to 1 Castrol 927. Changed it up to 36 to 1. After a 1 mile run at 1/4 throttle the porclen on the plug is a pretty brown, the electrode is kinda black, rich looken with a bit of oil on it.

Now I had a Husky dealer tell me that I may have to go up to a 4.0 slide or somewhere in between a 2.5 to 4.0. Had another dealer tell me to run 50 to 1. Had another tell me to change gearing to a 12/56. Im running 11/53 now. Had another tell me my diode was going out on my Motoplat. Sudco tell me I need a 50 pilot jet which is comeing snail mail. Not one had the same answer twice. I guess every mind is a different world.

Maybe someone else has had this issue and is willing to pass on knowledge. Im haven fits, cuz I have never had this much trouble with tuning a carb.
 
Well I guess a few of you are curious whats going on, but no one posted suggestions. I possibly posted the beginging of this in the wrong place. I did finally get some answers to my issues in a phone conversation. Theses are some of the questions a well respected Husky engine tuner said. (1) Did you grab Right side crank end and try moven it up and down, maybe your crank bearing is going bad. (2) Top end in good shape. (3) Did you repack your silencer. (3) Did you check for any mice nests in your exhaust pipe. (4) Did you try adding a bit of choke at that throttle position, and a few more questions, but those were the most important. His answer, your running to fat.

Carb parts are ordered. I trust the man with his advice. If all goes well I will post the changes here in about a week when I get the parts and some time off from work to put them in and run. If I have a chance in the next few days I will post some interesting facts about a Mikuni. These charts should be helpful to some, others may have them already. But they were hard to find. I may also post them in the tech reference section as these charts are not in the Mikuni vm tunning manual to my knowledge.

If your gonna do the Husky hop, do it right. WFO ****************************************
 
For comparison here is from a vintage jetting chart for - Last number is the slide and the second to last unsure Just picked up an 82 250 engine so keep the updates coming

HVA 250 -82
Mikuni VM 38
430​
45​
R2​
6DH3​
2.0​
2.0​
 
I missed this earlier. This is copied from another thread by Husky T. For a 1980, but should be close.
Jetting info From Procircuit CR 250 and 390

Jetting for 250/390 CR 1980 ProCircuit
"Here is the reccomended jetting for the 1980 250/390 CR from ProCircuit for Southern California elevation 0 to 3000 ft

Pro Circuit knew Huskys back in the day information is a direct quote from ProCircuit

250 CR Husky 1980
38 mm Mikuni Round slide
Stock Needle 6DH3 change to 6F15
Stock Main jet 430 change to 480
Stock R2 Needle Jet change to R0 or Q8
Go to a 60 Pilot
These changes from the stock factory bike will result in cleaning up the bottom end and make the top end a lot fatter.

390 CR Husky 1980
38mm Mikuni Round Slide
all the same changes but go with a 50 Pilot

Also recomended:
Throw away the stock Husky air boot clamps and replace with standard hose clamps
Seal the air boot to the air box with Silicone Sealeant

T"
 
Here is the jetting for my 84 wr 250. Again not exact match but hopefully the info helps.
42 pilot Q-4 needle jet, 6F-16 needle, 410 main, 3.0 slide.
This was setup by husq.fleet. He is very knowledgeable and is always willing to help. You should be able to pm him. If no luck I will hit him up for you if you like.
 
I have had good results with the dial a jet and UFO from thunder products. Both items work really well on round slide Mikunis. I got the jetting pretty close on my xc500, but still had some funky carbureting areas. I installed the dial a jet and UFO as recommended by the manufacturer, and now it runs crisp all the way thru the rpm range. Since then, I have installed it on all my 2 strokes- a banshee and 05 cr125, and have had similar results. I was scheptical at first, a lot of people seemed scared to try it. I read some magazine testamonials with positive feedback and decided to give it a try. I think it was money well spent.
 
Thanks for the replys !! I see that some of the posts are pretty darn close to what was ordered. Once I get the parts and run the old girl I will post what worked best. BTW, that dialajet is interesting and the UFO makes sence
 
hmm. have now done a days riding, and it seems rich? sputtering along at any cruise light throttle, smoking a bit and slight oil spray. i wonder if increasing the bore from 240 to 250 makes it suck more fuel, or did i richen it for break in, then forget that i had done so. it spent 3 months in my apartment livingroom under repair, and i dont recall what all ive done. another is new crank seals n bearings.
the symptom is erratic onset of power, and to run smoothly the throttle must not be stationary, rather opening gradually or fast, but not constant at any position. i think ill start by looking up initial settings for both the 84 wr240 and 250 to see the differences in settings. i might have lowered the needle clip. if i recall it was originally on second groove from top and maybe ive put it on third. i hope thats all it is. perhaps 30:1 is too much oil and rich fuel/air. i llike extra oil, and the good stuff. dont want to blow motor again! leaning the carb is like panning for gold, it makes me knees tremble. you need a very fast bike for gold panning, you see, theres no wastin time to getting there, and also to get away quickly if your on somebody elses claim. hypothetically speaking.

went rippin, lowered jet needle by 1 clip position . i forgot i had raised needle for a break in. now thats more like smooth power and consistent
 
I didnt see where you verified the float level was correct. A high float level will give a rich off idle/midrange just like the needle jet is too big. I would also try a size or two smaller needle jet.
 
OK OK Stop!

Until you can verify that the crank seals are perfect and you are not pulling oil from the gearbox - or losing crankcase compression into the gearbox past the left side mains seal, you will always be wondering. Likewise drawing air or letting air into - and out past the ignition cover.

When you do replace the seals, be sure to use double lipped Viton seals. The left seal has its spring side facing the clutch cover. The right seal has the spring side facing the crank - both as you would be sat on the bike.

Assuming all is now fine, get the bike to run flat out, slightly up - hill, so it is under load and get the bike to run perfectly on the main jet, going from 'say' 450 down to what works best. Forget any other jetting until this is right, giving a nice light brown plug colour.

It doesn't matter what main jet everyone else is using, just go with what works. Also, be consistent with fuel. Use the same grade you always do and an oil ratio you are happy with. Again - don't worry about what other people do, just be consistent.

I think if you get to this point, you will then find selecting the smaller jets and needle adjustments easier, as you will not be masking over the problem of having the wrong main jet giving false readings.

I do simpathise, as I have built a couple of 300cc Huskys recently (based on the 250 motor), and It has taken me a lot of testing to get the jetting right.

Hope this helps!

Andy Elliott
 
You can not change the pilot jet size without affecting the main jet. The pilot jet feeds fuel in front of the slide at all times, seperate from the main circuit.
With the correct pilot jet the bike should idle nicely with the air screw turned out between 1 to 2 turns.
More than 2 the pilot is to large. Less than one the pilot is to small.
Get the pilot jet right first, then go after the main jet.
 
Try a 3.0 slide. The 2.0 is way too rich. Your other jets are close but you'll have to finalize your own settings.
 
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