500WRLC

[ajcmbrown]

I have searched this forum for an idea that I have in mind for a future project but cannot find any definitive info, I believe it is possible to build a 500WRLC by using a 400/430 bottom end with 500 crank, cylinder and head, my question is whether or not the 400/430 gearbox is up to the task?

Has anyone here built one of these before? I would be surprised if it hadn't been done unless there is a very good reason not to.

Tony.

 

[suprize]

should all be the same Tony.

 

[ruwfo]

agreed 400/430 & 500 should be the same

 

[ajcmbrown]

So the 500's don't have a reputation for eating 6 speed gearboxes? The only reason I ask is that I read on this forum somewhere that the 6 speed gearboxes were a little weak, is that true?

 

[fran...k.]

The primary drive is different. The fingers of the clutch basket (5 spring) for the 500 are solid while the others are kind of shaped like structural steel channel. I suspect the primary drive for a 500 six spring clutch is quite rare. Half the gears are the same as some or most of the 250 are not they? The actual gears and shafts for a 430wr are the same as a 500xc and the one year they made a 500wr. Of course the input shaft changed 87-88. You will need the 500 head nuts.

As to the gearboxes being weak. The problems of the bearing pockets enlarging will be the same if a 4 or 5 speed shaft and gear assembly are in there. I never have had let alone had apart any 4 or 5 speed gearboxes. The problems with the six speed ones, including the one 250 I have had apart are in second and third gear faces and engaging parts. It can be pretty hard to find a good third gear. The part third engages to also can be a bit banged up. Weak or not the 430 wr/xc 500xc, 510te transmission gears share the part numbers in the six speed four stroke Italian for another 10 years.

 

[slosh]

When I bought my first Husky (from a tender style auction) I had no clue about anything Husqvarna other than the bike I bought was cheap and it started.
I was convinced it was an 85 WR 400 for years as it had a headlight, WR rear subframe and six speed box. A serious oil leak forced an engine rebuild, which made me look for parts, found Café Husky and discovered that my bike had a CR brake stay rear wheel/ swingarm and it was a 500. A 1986 500cr in fact.
Since I did not do the engine rebuild I don't know what bottom end parts are WR (or XC) and what is CR but I could pull the cases off and have a peek if you want.

 

[fran...k.]

Has anyone here built one of these before? I would be surprised if it hadn't been done unless there is a very good reason not to.

Tony.

I will answer this the second question here.
I at one point intended on putting the water cooled 500 in the dual shock water cooled 400 dual shock frame. I have yet to do it, a good reason for postponing is that I have not been real successful starting the two water cooled 500 bikes I bought whole and running. One the guy I bought it from could start it multiple times in front of me and after much frustration I made it a parts bike. Maybe with a compression release and a fresh bore job things would be different.
It would to me be more sensible to start with a 500xc and use the shorter suspension and what else one felt like.

 

[2premo]

I have searched this forum for an idea that I have in mind for a future project but cannot find any definitive info, I believe it is possible to build a 500WRLC by using a 400/430 bottom end with 500 crank, cylinder and head, my question is whether or not the 400/430 gearbox is up to the task?

Has anyone here built one of these before? I would be surprised if it hadn't been done unless there is a very good reason not to.

Tony.

I have swapped gears and cranks back and forth to keep certain bikes going
the biggest difference besides the crank and barrel is the primary gear set, it is unique to the 500XC 39:70 ratio vs 33:76 CR500 and 430 400
i have only ever lost one gear box, 3rd gear on an 87 430XC so they really are tough

 

[fran...k.]

The primary drive ratio has an effect on how far around the crank goes with one kick.
The 500 two stroke with 33:76 has a few more than the ten teeth built into the input shaft for first gear.
Pretty sure the air cooled 430 had the 39:70 primary drive.

 

[ajcmbrown]

Thanks Slosh, don't go pulling your bike apart just to satisfy my curiosity, besides I think 2premo has answered my question, it can be done and the 6 speed gearboxes are quite tough.
Is there a reason why the primary gearing changed for the 500, or could the 33/76 primary be used?
Would it have any drawbacks, assuming the primary gear can fit the crank of course?

 

[2premo]

Thanks Slosh, don't go pulling your bike apart just to satisfy my curiosity, besides I think 2premo has answered my question, it can be done and the 6 speed gearboxes are quite tough.
Is there a reason why the primary gearing changed for the 500, or could the 33/76 primary be used?
Would it have any drawbacks, assuming the primary gear can fit the crank of course?

33:76 is fine unless you are looking for high speed, with the 39:70 they were known to do 100mph stock
add a tooth to the countershaft and dirt riding becomes a blur

 

[ajcmbrown]

Back in 1992 my 400WR was clocked at 95 mph, though I don't know how accurate that was and don't remember the final gearing.

 

[fran...k.]

The primary gearing did not change in the 500 two stroke the way I see it. From 1982 1/2 on the six speed had the 39/70 and the four and five speed had the other one. The 430 with the six speed is the one that changed over time. I am not real sure about the few 1987 500 bikes but pretty sure about the others.
a) kicking
b)torque able to put on the clutch
c)how fast around the starting gears go that seem to wear out
d)how fast the transmission is spun around, faster is less point loads

It is kind of a mixed bag so to speak. If you can start it chances are the clutch will slip to protect the transmission they are supposed to design things that way. That is what I attempt to point to here. It would seem likely the 4 and 5 speed transmissions have wider gear faces and more robust engaging dogs.

 

[2premo]

The primary gearing did not change in the 500 two stroke the way I see it. From 1982 1/2 on the six speed had the 39/70 and the four and five speed had the other one. The 430 with the six speed is the one that changed over time. I am not real sure about the few 1987 500 bikes but pretty sure about the others.
a) kicking
b)torque able to put on the clutch
c)how fast around the starting gears go that seem to wear out
d)how fast the transmission is spun around, faster is less point loads

It is kind of a mixed bag so to speak. If you can start it chances are the clutch will slip to protect the transmission they are supposed to design things that way. That is what I attempt to point to here. It would seem likely the 4 and 5 speed transmissions have wider gear faces and more robust engaging dogs.

you are correct, the 4 speed gears are quite wide

 

[justintendo]

i have 1 4 speed transmission from a 500cr, the gears are huge!

 

[SteveJ]

Just for reference, here are some pictures that illustrate the things mentioned above. These are from my air cooled 500. The four and six speed gear sets. Although the six speed gears are narrower, I've haven't heard of anyone breaking the gears, but as noted by Fran...k above, some have reported damaging the engagement dogs. I thankfully haven't myself and the bike is more fun with the six speed. The third picture shows the large crankshaft gear in the primary gear set, which makes starting somewhat of a challenge when cold. this is a 39:70 primary. The fourth picture shows the solid style clutch basket used on the 500s.