synthetic oil on old 18:1 chainsaw?


Old 11-25-07, 01:33 PM
Thread Starter
Join Date: Aug 2006
Location: usa
Posts: 902
synthetic oil on old 18:1 chainsaw?

Can I use the newer synthetic 2 cycle engine oil on my older Jonsered (sp?) chainsaw? It takes a 16 or 18:1 ratio, much lower than the new stuff. How do I determine the correct mixture?

Sponsored Links
Old 11-25-07, 03:30 PM
Join Date: Jun 2006
Location: St. Louis
Posts: 2,365
The old 2 cycles will run on any oil designed for 2 cycle engines, the newer oils are designed to give proper lubrication and meet the EPA requirements at a 40:1 50:1 ratio.
To calculate the measurements divide 128(ounces in a gallon) by the ratio ie. 16 for 16:1

128/16 = 8 , so for 16:1 you need 8oz. oil to 1 gal gas
128/32 = 4 , so for 32:1 you need 4oz.
128/40 = 3.2 40:1 3.2
128/50 = 2.6 50:1 2.6
Old 11-27-07, 11:45 AM
puey61's Avatar
Join Date: Apr 2004
Location: Upstate New York
Posts: 3,224
If you had the original owners manual for the saw you'd also find that the recommended oil was SAE40 engine oil, not 2-cycle oil. I've had good luck with Opti and AMSOIL synthetic oils in all two stroke engines. Never once had a return with a seized engine using either of these oils, even with the old Homelite chainsaws that called for the 16:1 ratio with 40 wieght oil.
Old 11-30-07, 06:44 AM
bontai Joe's Avatar
Join Date: Apr 2004
Location: Pennsylvania
Posts: 592
So you guys have had good experiences with the new synthetic oils in a 2 stroke? Any other advantages besides it runs well, like the mix being more stable if stored a while? etc.? I ask because I'm totally ignorant on synthetic oil in this application.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes