Clutch Basket Question

[chris squires]

Hi,

I recently split a 430cc WRLC engine for rebuild. To my astonishment when I removed the clutch cover two kicktart shaft pawls dropped to the ground, oh dear this doesn't look good!
Further digging revealed the kick start idler gear's needle roller bearing had also disintegrated, spraying material throughout the engine, contributing to the loss of a tooth on the first gear output shaft side (now replaced) and some damage to the clutch basket 'ring gear'.
I have cleaned up most the deformation on the clutch ring but it is in a bit of a state.
This is my third rebuild and I would really like to use this one piece clutch basket, but could someone with a bit more experience than me offer some advice? Is this part usable or not? I aim to use the bike for some street riding and some competitive enduro races?



Please see the attached, The final image shows the worst of the damage.

Thanks for any advice!

Chris



View attachment 51794View attachment 51795

 

[wrx]

you need a basket my friend. the kicker idler bearing is a common failure. my 85 cr250 is in the same condition. find a good donor motor and start from scratch.

 

[hva-factory]

What is the 3 digit number on the back of the basket Chris? (there are at least 4 variations)

Andy

 

[chris squires]

you need a basket my friend. the kicker idler bearing is a common failure. my 85 cr250 is in the same condition. find a good donor motor and start from scratch.

Thanks wrx

I have a mint 250 basket and matching primary drive crank gear, do you think I could use that as a donor, I'm a little concerned about it not taking the torque of the 430 motor!

Thanks

 

[Bigbill]

The strength of the material should be the same. The 250 ratio maybe different. The 250 ratio maybe lower so you use third through fifth gear more. First gear will be like a granny gear.

 

[chris squires]

What is the 3 digit number on the back of the basket Chris? (there are at least 4 variations)

Andy

Andy,

It is stamped 403 and is the six spring clutch.

Thanks

Chris

 

[chris squires]

The strength of the material should be the same. The 250 ratio maybe different. The 250 ratio maybe lower so you use third through fifth gear more. First gear will be like a granny gear.

so the difference between the 250 and 430/500 basket which I think are the same is purely for ratio (engine speed) purposes, so could be used if compensated at final drive (secondary ratio) then?

Thanks Bill

 

[Bigbill]

You could raise the sprocket ratios to compensate for the lower primary ratio. Either a larger front sprocket or smaller rear sprocket. Yup your right. With the lower ratio primary it's less wear and tear on the motor. But there's more torque going through the tranny. It shouldn't be a problem. It's more of mechanical advantage.

A larger front sprocket increases the chain life by lessening the chain wrap. A larger diameter is less force on the chain. Figure it out on paper both standard ratios the figure out your new primary ratio then adjust your secondary or final drive ratio so it's close to the numbers of the original final output. It should pull harder with the lower ratio primary. You could be on to something?

I like the bottom end hit. To me it's wick it and hang on. I know it's right when I hit it standing up and the bike wants to leave me. Power I like it.

 

[Kartwheel68]

so the difference between the 250 and 430/500 basket which I think are the same is purely for ratio (engine speed) purposes, so could be used if compensated at final drive (secondary ratio) then?

Thanks Bill

Yes, they parts are identical except for the gear ratio. The easy fix for the hard starting on the air cooled 430 is to put the 400LC primary gearing, or the 250 if you cant find the 400 gearing, in place of the stock ratio.

 

[hva-factory]

We have new ones and a mint used one...

Call me if we can help!

Andy

 

[chris squires]

You could raise the sprocket ratios to compensate for the lower primary ratio. Either a larger front sprocket or smaller rear sprocket. Yup your right. With the lower ratio primary it's less wear and tear on the motor. But there's more torque going through the tranny. It shouldn't be a problem. It's more of mechanical advantage.

A larger front sprocket increases the chain life by lessening the chain wrap. A larger diameter is less force on the chain. Figure it out on paper both standard ratios the figure out your new primary ratio then adjust your secondary or final drive ratio so it's close to the numbers of the original final output. It should pull harder with the lower ratio primary. You could be on to something?

I like the bottom end hit. To me it's wick it and hang on. I know it's right when I hit it standing up and the bike wants to leave me. Power I like it.

Its good to know it can be done, and it appears there might be some advantages to be had. Thanks again for your input Cheers

 

[chris squires]

Yes, they parts are identical except for the gear ratio. The easy fix for the hard starting on the air cooled 430 is to put the 400LC primary gearing, or the 250 if you cant find the 400 gearing, in place of the stock ratio.

I forgot all about this trick. Cool it leaves options open, thanks Kartwheel

 

[chris squires]

We have new ones and a mint used one...

Call me if we can help!

Andy

Cheers Andy

 

[GaryM]

One more option for using the two piece clutch the one bolted to basket is Ric Horvart has some remanufactured 81 82 clutch ring gears

He has new kick gear made in both styles - the small tooth idle gear and large tooth idle gear style. The gear is attached to the old ring gear.

Its cost is about $300 for this gear.