Jonsereds 621 fuel mix

[landyman]

Evening chaps,

 

My dad is about to dig out his '73 621 to ring up some beech. Now the original user manual states it should be run on 16:1......Wow thats rich I thought but it did come from an era when oil technology wasnt that great and also i think it may have a cast iron bore instead of nikasil plated. So I told my old man i'd mix him up a 25:1 mix using some of my fully synth oil, the only thing that crossed my mind is that being an old saw, fully synth oil might not be the best to use in it and I perhaps should use some sort of vintage 2t oil.

 

Thoughts on this matter pls?

 

Many thanks

 

Pete

[woody paul]

My old boss had a 621 ran it on 50:1 good 2 stroke oil with no problems

[SawTroll]

Mine has been run on 50:1 Aspen as long as anyone remembers.

 

The change in recommended mix ratios since around 1970 mainly has been caused by better oils - and the 621 cylinders are Mahle ones with Nikasil plating.

[Eddie@aspen]

Evening chaps,

 

My dad is about to dig out his '73 621 to ring up some beech. Now the original user manual states it should be run on 16:1......Wow thats rich I thought but it did come from an era when oil technology wasnt that great and also i think it may have a cast iron bore instead of nikasil plated. So I told my old man i'd mix him up a 25:1 mix using some of my fully synth oil, the only thing that crossed my mind is that being an old saw, fully synth oil might not be the best to use in it and I perhaps should use some sort of vintage 2t oil.

 

Thoughts on this matter pls?

 

Many thanks

 

Pete

Hi,

 

We have lots of collectors of classic saws all running on Aspen2 at 50:1 as you say it was made before 2-stroke is advanced as it is today.

 

Bit like the handbook for a old car saying to use crossply tyres when we all know things have moved on.

 

Kind regards

 

Eddie

[GardenKit]

Crossply tyres?

 

That's showing your age Eddie!

 

Do you remember the stupid advice when changing over in stages "crossplies on front, radials on back"? Lethal!!!

 

Barrie