Ot carbon fiber pull start cord ?,cant find

[MattiJ]

How about Dyneema, should be available in different gauges from your local arborist suppliers. Very strong stuff and abrasion resistant too.

Dyneema, Spektra or UHMWPE or whatever you want to call it has about 3000 lbs strenght in chain saw cord size
Good abrasion, UV and chemical resistance.
Slippery as hell and knots don't work well but even if you get only 20% of the strenght with ugly knot its still good enough

[MattiJ]

I am not very strong or ham fisted ,but I have broke the cords on 2 diferent stihl saws and a Polaris 4 wheeler and an expensive honda mower.Nylon pull cord has been about the same for fifty years. I am not looking for a '' LIFETIME GAURANTEE''. I want a cord that WILL last a lifetime. Edwin Dirnbeck

Try the 6mm version for Polaris:
https://www.marlowropes.com/product/...rand-prix-rope

11 000 lbs rating so it should have decent margin even if you use it with Caterpillar to pull your 4-wheeler out of swamp.

[Yondering]

I am not very strong or ham fisted ,but I have broke the cords on 2 diferent stihl saws and a Polaris 4 wheeler and an expensive honda mower.Nylon pull cord has been about the same for fifty years. I am not looking for a '' LIFETIME GAURANTEE''. I want a cord that WILL last a lifetime. Edwin Dirnbeck

What you need to look at is not strength of the cord (guessing that's why you thought carbon fiber would be good?) but resistance to abrasion and aging. You're not breaking cords in their new condition from pulling too hard, they break from abrasion or the material properties decaying as they age.

Regarding abrasion though - technique matters a little there too; pulling the cord directly away from the hole will let it last longer than pulling it to the side. Avoid forcing the cord to bend over corners and rub a lot.

[RichR]

I am not very strong or ham fisted ...

Really?

... ,but I have broke the cords on 2 diferent stihl saws and a Polaris 4 wheeler and an expensive honda mower.

This would suggest otherwise.