Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Solo => Topic started by: adam32 on July 08, 2014, 10:12:22 am

Title: 603 top end on 680 bottom end...
Post by: adam32 on July 08, 2014, 10:12:22 am
So I'm thinking I might try it for a 6 cube saw. A stock 603 has a 56mm bore and 42mm stroke so it's 103cc, just above 6 cube. So if I take that jug and put it on the 38mm stroke 680 bottom end then it'll be 94cc, right in the middle of the class. Or stroke it to 40mm and be right at 99cc  ;D ;D ;D

The beauty of the 603 jug is the removable transfer ports  ;)
Title: Re: 603 top end on 680 bottom end...
Post by: KilliansRedLeo on July 08, 2014, 01:27:09 pm
Adam, that REALLY sounds like a neat project! Keep going!
Title: Re: 603 top end on 680 bottom end...
Post by: aclarke on July 08, 2014, 03:51:17 pm
Have you tried doing it the other way around? Smaller 680 jug on the longer stroke 603. Could have a lot of torque with the extra stroke.  Rod the same length?
Title: Re: 603 top end on 680 bottom end...
Post by: adam32 on July 08, 2014, 05:15:33 pm
Have you tried doing it the other way around? Smaller 680 jug on the longer stroke 603. Could have a lot of torque with the extra stroke.  Rod the same length?

I did try that a while ago, it ran for a couple minutes too lol. I need to make a better spacer and figuring out the port timing was a pain in the azz, I tried several 52mm pistons, even made a couple pop ups to try.
Title: Re: 603 top end on 680 bottom end...
Post by: aclarke on July 08, 2014, 10:36:41 pm
Ok.  The big jug route might be easier do they both have a
"spigot" on the cylinder or flat?
Title: Re: 603 top end on 680 bottom end...
Post by: adam32 on July 08, 2014, 10:47:27 pm
Both have the spigot...thought about cutting it off...