Jetting

[schimmelaw]

Hawaii,

Bless you - just the type of material I wanted. Thanks. Any More? Not to be a pushy dk head BUT please post more or any of the Husky material you might have or find. Any and all models?

Rick

 

[HuskyT]

Hey guys. This is my first post so i hope that it works out. I have 2 1980 420's. They are wicked bad. They make my 81 Maico 490 seem tame. With out a doubt the best motor husky ever built. 430's are short shifters and vibrate a lot. 500's rev out even less and vibrate more. The 420 motor will put the boots to either one of them in my experience. A stock pipe will work just fine. I run one on 1 of my 420's, and an Asche/Uptite pipe on the other. Both bikes are scary fast at any rpm, and they absolutley scream when you turn em loose. I have riden them all, and the 420 motor is the best IMO. A 390 is a very powerful bike by anyones standards, and they are very underated, but the 420 will make you feel like a little school girl. When i have time I will post some pics. One bike is a factory ProCircuit bike from back in the day. The other is a 420 conversion that i did myself. Both rock.

My jetting recommendations are as follows for 2500 ft, but will definitely be in the ballpark whever you are at.

480 main
2.5 slide (3.0 is too crisp) Husky's like to run a bit rich
40 pilot
2.0 air jet (inside of bell at the back of the carb)
R2 needle jet
6DH3 needle jet

14 counter
56 rear

Watch out bud! Your arms are gonna be longer when you get off this beast.

Take care guys - awesome forum.

Welcome to the forum Plesh 490 .... you sent me some very nice pics a while back of your 390's when I emailed you from the Husky Yahoo Group. Thanks for joining in over here.
I'm restoring a 1980 390.

Are you running a 17" rear wheel... I'm going to be running a wheel off of an '82


Tim ( HuskyT)

 

[tapio]

Hi! anybody have a cr500 w/38mm carb?

I m going to try an flat side on my 500 and would like some jetting tips to get me started.

Thanks!

 

[Picklito]

The Keihin PWK fits on really well where there was a 38mm Mikuni round-slide (390's, 430's, 250's). I've got several KTM versions lying around and just about any would work well, either 38 or 39mm models. Actual jetting will depend on which carb body you end up with, because they changed things over the years like the height of the shroud and that effects the fuel draw quite a bit.

On a 430 I've got a 39mm carb with the 6mm tall shroud. Based on what my big KTM's run (500 and 540) I threw in a 45 pilot, 6.0 slide, DGH needle and 175 main jet. It's a little rich across the board, but that's a safe starting point, and should be a safe start on the 500, too.

One issue you'll have for the 500 swap is the intake boot. The 500's came with 44mm Mik's in 82.5, then 40mm Mik's for 83/84. I think the I.D. of the intake boot will be too big for a PWK. Find one of the 250 intake boots from 82-on and you should be good to go.

 

[Leftcoast leftkicker]

I talked to Carb Parts Warehouse last month and the dims on the PWK's didn't match up to the inside dia of the inlet on the engine side or the airbox side. Did you machine yours?

 

[plesh490]

Here ya go boys. Just got er finished. Look close and you will see a lot of very hard to find trick stuff. One off factory swingarm, D&H intake (pre mossbarger and bigger), PC brake pedal, Terry brake rod conversion, Terry fork kit, 18 in Ohlins piggys, NOS Uptite/Asche pipe (still has the sticker), PC ported cylinder, PC greaseable chain tensioner, vibration welds (verticle on the cylinder) - To answer Rick, there are Asche pipes still out there, but you have to hunt for them, they are very hard to come by. You can shorten up a stock pipe if you have the specs (i believe that they are on this forum somewhere) and it will work great. The biggest advantages of the Uptite pipe are that it has the correct chamber volume for the 420 displacement and they are way lighter. I run a stock one on my other 420 and the bike screams nightmare scary style. - To answer HuskyT, I run a 17" Bridgestone M22 with a little less air pressure. Husky knew what they were doing with the 17 inch. They have a taller sidwall, and are wider. If you run a little less air pressure, the extra sidewall acts as another suspension component, effectively helping the beast to "track" better. Makes sense huh. The ProCircuit 420 is unbelievably fast, so fast that it is scary to even a salty veteran like myself. I LOVE it. The closer i come to death, the more i like it.




Please, please and pretty please post photos of your ProCircut 420. Have the same bike and would love to see what you are working w/. Thanks in advance.

Asche/Uptite pipes still available? Want/need something other than the stocker.

Rick[/QUOTE]

 

[hawaii-rider]

Major Droooool factor here.........WOW

Dude, you need someone to break that thing in for you?
I should have it done (the formal break in) in a bout 12-14 months.
let me know just ship it up!


Okay....where did you get the brake pedal and some close ups of the brake pedal and mount. My XC500 pedal is a joke...

nice job on her...I just decided my Next Vintage EVO will be a 430.
period
end
DOT.

HR

:usa:

 

[plesh490]

Dude, you need someone to break that thing in for you?
I should have it done (the formal break in) in a bout 12-14 months.
let me know just ship it up!


Okay....where did you get the brake pedal and some close ups of the brake pedal and mount. My XC500 pedal is a joke...

nice job on her...I just decided my Next Vintage EVO will be a 430.
period
end
DOT.

HR

:usa:

That is a ProCircuit greaseable brake pedal from 1980. PC was one of the only companies that worked with Husky's back in the day. Mitch Payton (PC founder) was a Husky dealer and got the ball rolling ona lot of stuff. I got mine from a friend who's brother was a Husky factory support rider from the late 70's-early 80's. He had access to all kinds of trick stuff. I am very lucky to have been able scoop it up. I have NEVER seen another one like it. The chain tensioner is gold anodized, and has a zerk fitting also. Both parts are much better than what came stock. A 430 can be a monster if they are set up right. Clean up the transfers and raise the piston window a bit. It will come alive bigtime. Put on the right pipe, and you will have something NASTY. Take care. Thanks for the props bud.

Jared

 

[Picklito]

I talked to Carb Parts Warehouse last month and the dims on the PWK's didn't match up to the inside dia of the inlet on the engine side or the airbox side. Did you machine yours?

The stock Mikuni VM38SS carb is 43mm on the reed side and 62mm on the air filter side.

The PWK is 46mm and 62mm. So, the reed side stretches the rubber boot just a touch, but fits normally into the back. I've had no problems and it looks stock. The PWK is also a bit shorter which makes it slip in and out a bit more easily. The original Mikuni had that loooooong intake bell and it can be a bit tricky to snake in and out of there. I also used a KTM Domino throttle and cable. It's working great. Few ounces lighter than a Mikuni, too.

The front rubber boot, by the way, is a standard Mikuni/Sudco part VM36-200. You can buy them inexpensively through just about anybody.

 

[Leftcoast leftkicker]

Jared- that 420 is the bomb! BTW, Up-Tite made the brake pedals and chain tensioners you're describing but they're hard to find & George won't make any more. Same with the pipe, I've begged & pleaded (as have others) and he has all the jigs but just won't do it. I had one on my '78 390 he built up for me in the mid-'90s and it was INSANE. There are A LOT of people who would buy replica U-T/Asche pipes.

That cylinder welding is pretty trick, hadn't seen it before. Wonder if i could get Applied to make a set of -2 degree triples for my FoxForxs??

Regarding 430 porting, i raised the exhaust port 1mm and squared off the back (only) of the transfers and it does perk it up. Bigger gains from grinding down & smoothing the exhaust "hump" (looking from the outside of the exhaust spigot into the cylinder- you'll see a hump on a stock cylinder) which allows for smoother exhaust gas exiting. I've also played with different squish settings (settling on mid .30s to low .40s) and run race gas & Spectro 40:1. Using a Vintage Iron pipe (lighter than stock and more volume) but have also heard good things about the pipe from Maicos Only.

 

[plesh490]

Thanks Leftcoast. I've been into Husky's forever. I love um! I have talked to George about reproducing his pipes too. I think that it would be a good move for him. Husky's are gonna come on strong with all of vintage stuff blowing up. I think that Maico Only builds the pipes for Vintage Iron. Haven't ever tried one. I have seen your bikes too. Very nice brother. Porting is the way to go on a Husky. They just need a little attention in that area. Get um right, and you won't want run anything else. Sounds like you got the 430 motors figured out. The verticle welds on the cylinder really help to tone down vibration, and adds strength. A 430 can be a very NASTY motor as i am sure you know.
Older race bikes just need more attention/setup, that is why it is so addicting. You know that maico guys deal with a lot more issues than Husky guys, mostly because they had crappy quality control. Gimme a modified Husky, and I will give you a whooped on Maico any day. - Fox Forks? I have been looking for some forever. Cool that you got a set. Just as a suggetion, you could use some 86 Husky triples and have them bored to accomodate the Fox 44mm tubes. The 86 triples really help to bring in the rake, more so that a set of 81-84 40mm triples. All you have to do is machine a spacer to compensate for the difference in steering stem length, and you can find them pretty cheap. Good stuff Leftcoast. Take care.

Jared

 

[Leftcoast leftkicker]

Hmmm, hadn't thought about the '86 triples, you say the offset was changed on those? I know they started (way late) to modify the head angle but didn't know they also changed offset. The FF triple are about the same as stock Husky's (eye ball) but if there's a cheap way to pull in the offset (and it doesn't crap the rest of the bike out0 then I'm gonna start looking at it hard!

 

[Picklito]

Regarding 430 porting, i raised the exhaust port 1mm and squared off the back (only) of the transfers and it does perk it up. Bigger gains from grinding down & smoothing the exhaust "hump" (looking from the outside of the exhaust spigot into the cylinder- you'll see a hump on a stock cylinder) which allows for smoother exhaust gas exiting. I've also played with different squish settings (settling on mid .30s to low .40s) and run race gas & Spectro 40:1. Using a Vintage Iron pipe (lighter than stock and more volume) but have also heard good things about the pipe from Maicos Only.

Leftcoast,
I just picked up a really clean early 81 430 WR that's had some obvious cylinder work, 'similar to' what is suggested in the Husky service bulletin from that time (transfers opened at the base gasket, re-angled a bit, intake boost ports reshaped, piston window reshaped, reed block streamlined and V'd at the inside of the tip). I also measured the squish... which came out at .044" with a new off the shelf base gasket (stamped 1.2mm thick). I don't know the history of this motor, but a squish like that was probably set very carefully. I know the later 430's were sent out a lot looser than that (I had a late 82), mainly because some of the early ones were too tight and smacked the head (I've got one of those on the bench right now, and there's a service bulletin warning about that, too). As far as I can tell, they opened up the squish by machining back the squish band in the head - you can see this step in my later heads, but this early 81 is flat across from the mating surface through the squish band.

What I'm curious about is how you set the squish. As far as I know, Husky only made the one thickness of base gasket, and the squish you get is what you get. Are you making your own base gaskets in different thicknesses ala KTM, or are you machining cylinders and heads? And based on that, what is your final exhaust port height? The service bulletin mentions 40mm for a WR and 39mm for a CR or XC. Mine was at 40mm from the top of the cylinder, but that would be 40-1.1mm from TDC. Unfortunately, Husky is not very clear on this in the service bulletin.

 

[Leftcoast leftkicker]

Picklito- I use 3 types of base gaskets, 1 is available from my parts whore in OH and is built sturdily and thick, the other 2 (medium and thin) are paper and available from John at Vintage Husky. Honestly, I didn't want to machine the cylinder so I just tried all 3 and measured (measure at the wrist pin side of the piston). For my bike (with the stepped head as you described) the thin gasket gave me high .20s and the thick high .40s so like Goldilocks I went for the medium. I did run the flat head (no step) and played with squish but blew it up.

I measured exhaust port height from the top of the cylinder down then raised it up 1mm.

The 430s changed a lot over their first 3 years and Husky played with porting having learned from the race teams and PC. Mine's pretty tame, set to the Service Bulletin specs, VI pipe and Mossbarger.

 

[Picklito]

Cool! That gives us 3 base gaskets to work with. From your numbers, it sounds like John's thin gasket is about .020"/0.5mm thinner than the current Husky gasket. That should be plenty to work with.

I've done a TON of this sort of cylinder juggling over the years on the KTM's. But for some reason I've always just "put a stock one in there" with the Husky. Then, one day, I started thinkin... and you know where THAT goes.

 

[Fritzcoinc]

Thanks for the info Steve.
No I do not want to sell it yet as I have only just bought it, but I have been having trouble starting it,I shall fit new jets and see if that helps.
Ian

An often overlooked item needed to start one of these two strokes is to hold the throttle open some while kicking.

 

[flyarmy]

I would also buy one or two of Georges reproduction pipes. I think he could sell a lot of these to the post vintage husky crowd. George...Are you listening to us?

 

[Picklito]

I'd buy at least one, probably two... and that's just for the current projects!! I'm finding that these 27 year old pipes are pretty much done.

 

[robertaccio]

i love that who grinds their own needles now,,thats brilliant

 

[schimmelaw]

I'll be number 3 in line for an after-market pipe. Does pretty please help at all?
Rick