I've read a variety of mix ratio's for the 090...any where from 20:1 to 50:1. I have a mid to late 70's 090AV and am running about 35:1. On the Chain Saw Collector Site, every 090 Model shows a different ratio. I have a newer factory manual, maybe mid 90's, which says 50:1. I'm hesitant to run that lean. Better a little rich than too lean. Just wondered what others who have this saw in this vintage are running?
090 Mix Ratio
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Lewis Brander
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Mix Ratios:
Leebo. There was a thread that had some info from Stihl and HVA. It stated something along the lines that the smaller saws (32cc range ?) could run 50/1 mixes just fine, but I would go to 40/1 for them with a known good oil. It also stated that mid cubed saws (around 5 cubes) should be running a 32/1 mix and saws over 7 cubes should be running 24/1 mixes. Apparently they were experancing crank/bearing problems and were changing their specs. I personally would run at least 32/1 mix with a known good oil and make sure the carb was adjusted for the mix and conditions of the day. Take care. Lewis.
Leebo. There was a thread that had some info from Stihl and HVA. It stated something along the lines that the smaller saws (32cc range ?) could run 50/1 mixes just fine, but I would go to 40/1 for them with a known good oil. It also stated that mid cubed saws (around 5 cubes) should be running a 32/1 mix and saws over 7 cubes should be running 24/1 mixes. Apparently they were experancing crank/bearing problems and were changing their specs. I personally would run at least 32/1 mix with a known good oil and make sure the carb was adjusted for the mix and conditions of the day. Take care. Lewis.
Lewis Brander
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Hello leebo:
Hello leebo. The only thing I've bought off ebay is some parts for the old saws I have. Buying saws is sometimes questionable and the shipping cost, can be rediculous and doesn't add to the value of the saw. Just call me a tightwad. I visit ebay to see what some of the old saws go for and to see what's available, but haven't bought any as yet. Take care. Lewis.
Hello leebo. The only thing I've bought off ebay is some parts for the old saws I have. Buying saws is sometimes questionable and the shipping cost, can be rediculous and doesn't add to the value of the saw. Just call me a tightwad. I visit ebay to see what some of the old saws go for and to see what's available, but haven't bought any as yet. Take care. Lewis.
ross_scott
ArboristSite Guru
I agree with you lewis 33:1 or 32:1 would be ok that is pretty oily I put that through my 034 and previously my old pioneer and the dolmar ps-34 that I just recently sold I just do not trust 50:1 after seeing the bore and piston of a husky 50 that was ran at that ratio.
Lewis Brander
Addicted to ArboristSite
Oil mix ratios:
Hello ross scott. About the leanest oil mixture I would run would be 40/1 for small saws, trimmers, weedeaters and these small roto tillers. Most of my saws made after 1960 seem to run fne on a 32/1 mixture, but the older saws I have, I run on 24/1 mix. The old saws mainly had reed valves and ran at 4-6,000 rpm's, with the richer oil mixes at the time and with the newer oils of today they should run forever. Today's saws run at screaming rpms and if the carb isn't properly adjusted they will eventually seize up, so it's better to have a bit more oil in the mix. A new saw carb can be properly adjusted for that saw say, by the dealer, but once that saw has a few tanks of fuel though it it will most likely be running lean. Any saws I own, I start, warm them up, run them a bit and if needed adjust the carb for the running conditions of the day. If you last ran the saw in hot dry weather and now running in cold damp fall weather the saw is going to run differently and the carb should be readjusted for that days running (weather) conditions, altitude, barometric conditions, etc. I run my saw here at my home, then go to my brothers, then I'll have to readjust the carbs for higher elivation and cooler temperatures. I've adjusted his saw at my home and he usually will have to readjust it a bit after he gets home. Saws can be a bit temperamental, so a person should know how to adjust a carb and keep an eye and ear on what the saw is doing and how it runs. Take care. Lewis.
Hello ross scott. About the leanest oil mixture I would run would be 40/1 for small saws, trimmers, weedeaters and these small roto tillers. Most of my saws made after 1960 seem to run fne on a 32/1 mixture, but the older saws I have, I run on 24/1 mix. The old saws mainly had reed valves and ran at 4-6,000 rpm's, with the richer oil mixes at the time and with the newer oils of today they should run forever. Today's saws run at screaming rpms and if the carb isn't properly adjusted they will eventually seize up, so it's better to have a bit more oil in the mix. A new saw carb can be properly adjusted for that saw say, by the dealer, but once that saw has a few tanks of fuel though it it will most likely be running lean. Any saws I own, I start, warm them up, run them a bit and if needed adjust the carb for the running conditions of the day. If you last ran the saw in hot dry weather and now running in cold damp fall weather the saw is going to run differently and the carb should be readjusted for that days running (weather) conditions, altitude, barometric conditions, etc. I run my saw here at my home, then go to my brothers, then I'll have to readjust the carbs for higher elivation and cooler temperatures. I've adjusted his saw at my home and he usually will have to readjust it a bit after he gets home. Saws can be a bit temperamental, so a person should know how to adjust a carb and keep an eye and ear on what the saw is doing and how it runs. Take care. Lewis.
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