Oil mix ratio.

[North by Northwest]

I've always put 200ml of Stihl oil in 17 liters of gas so that's like 43:1 I guess? And never had any issues but sharp chains and clean saws make more of a difference than 40:1 vs 50:1 IMO

Absolutely , more saws damaged by dull chains and poor tuning then improper fuel / oil ratio's !

 

[Joseph W Santora]

Back in the mid '70s motocrossing in Japan we all used 20:1. Then someone smuggled in a 6 pack of BellRay Synthetic and we tried 50:1, and ran a gold spark plug of some kind, and the bikes ran like scalded dogs.

 

[sean donato]

Got to try and stop them blowing up somsomehow

I've actually never blow any engines up, normally just wear them out, and I can't say lack of lubrication was a cause in early demise.

 

[TBS]

Your link mentions Opel fuel but I'm not sure what that is. Any idea?

Only exists because stupid people huff gasoline.
https://www.bp.com/en_au/australia/home/products-services/fuels/opal-fuel.html

 

[tomalophicon]

Only exists because stupid people huff gasoline.
https://www.bp.com/en_au/australia/home/products-services/fuels/opal-fuel.html

Oh yeah I knew about Opal. Maybe it's a spelling mistake in the document.

 

[Ted Jenkins]

I've actually never blow any engines up, normally just wear them out, and I can't say lack of lubrication was a cause in early demise.

Lucky you. I will never forget the first few engines that I built lasted about ten minutes and some lasted about four. I was at least twelve or thirteen. I worked hard to get some specs and formulas on tuned pipe design. I had two bikes at the time. It took me about two weeks about a hundred hours to build the first. No it was not as pretty as the next few. So I mount the thing and start it up and wow. It went about an eighth mile down the road screaming so turned around to go back to the shop. About a hundred yards it completely stopped and to find that that there was a huge hole in the piston. What do you mean these things have to be carefully jetted. It took about a dozen pistons and bores to figure out about jetting and then the porting story for another time. Thanks

 

[Ted Jenkins]

Does any body like good burritos with some spicy salsa. A little salsa is great as it makes the thing taste like heaven. A little is great so about smother the thing is salsa. Not so good. So there is a balance to great tasting food. There is a balance with a well tuned chain saw motor and especially the fuel. To richen up the fuel air ratio will cool the piston and cylinder because that will make the combustion a little less efficient. Without adequate oil in the mix there will be less lubrication to achieve a little wear ratio. Too much oil will result in too much carbon that will stick to rings causing much wear. A great ratio that can be depended upon is 30:1 to 38:1. The source of oil does matter just not much. Thanks

 

[sean donato]

Lucky you. I will never forget the first few engines that I built lasted about ten minutes and some lasted about four. I was at least twelve or thirteen. I worked hard to get some specs and formulas on tuned pipe design. I had two bikes at the time. It took me about two weeks about a hundred hours to build the first. No it was not as pretty as the next few. So I mount the thing and start it up and wow. It went about an eighth mile down the road screaming so turned around to go back to the shop. About a hundred yards it completely stopped and to find that that there was a huge hole in the piston. What do you mean these things have to be carefully jetted. It took about a dozen pistons and bores to figure out about jetting and then the porting story for another time. Thanks

Must have sucked not having anyone around to teach you how to do things. I have 2 uncles that are career mechanics, dad is a career welder. Between racing and our normal activities I've about always had my head under a hood, and fingers in an engine.

 

[cookies]

use 100LL av gas mixed 20-1 with sae 30 non detergent synthetic oil ...saw makes so much power it drops panties 30 feet away and kills mosquitos like raid

 

[Huskybill]

I rebuilt 2t bikes, I learned to pressure leak down check the assembly. I started washing car parts for the oldman at 6 yo. I’m 70 yo now.

 

[Ted Jenkins]

I rebuilt 2t bikes, I learned to pressure leak down check the assembly. I started washing car parts for the oldman at 6 yo. I’m 70 yo now.

I will be 70 next year and have had a pretty good go around with 2 smokes. I still have about eight dirt bikes. My last race was at 62. I waited until the line left then fought my way to 2nd or third in the 50 class. I knew I had a whole mess of stuff to do so I knew had to take a break. Maybe will be back or not. I have never tested any dirt bike or chain saw motor for a leak down test ever. At this point never had to. When working professionally on jet skis snow mobiles and dirt bikes never checked any of those either as they ran well until retired or burnt. All my dirt bikes got rebuilt at 40 to 50 hours. Never had a chain saw that did not run well. If I questioned the compression the saw was rebuilt and of course all saws always got new seals. I have often wondered why people check their saws. My saws never sit which is maybe they have not stopped. Thanks

 

[Huskybill]

I had a used Honda 125 cr that drove me nuts. I found out in the leak down test the PO took a screwdriver to remove the cylinder from the case. After filing the cylinder base on the case it tested almost 8 hours holding pressure. Ran ok after that, I started checking every engine.

Every used 2t bike it’s crankbearing, seals, new piston, gaskets, reeds, clean carb, then ride the snots out of it. We rode the pipeline in mass miles from the car, not a place to break down.

 

[Vintage Engine Repairs]

32:1 both in my motocross bikes and now chainsaws.. brapp

 

[Ted Jenkins]

I had a used Honda 125 cr that drove me nuts. I found out in the leak down test the PO took a screwdriver to remove the cylinder from the case. After filing the cylinder base on the case it tested almost 8 hours holding pressure. Ran ok after that, I started checking every engine.

Every used 2t bike it’s crankbearing, seals, new piston, gaskets, reeds, clean carb, then ride the snots out of it. We rode the pipeline in mass miles from the car, not a place to break down.

When I was much younger would ride in the mountains and desert which seemed like a blast. As I got older only rode tracks with paramedics and a cold Gatorade five minutes away. In twenty plus years of tracks only had one engine that rattled as it crossed the finish line. A new fresh engine was installed before the next Moto. Thanks

 

[Huskybill]

I fouled a sparkplug once with a pack of coyotes not far behind me. I learned to change the plug before every ride.

 

[holeycow]

32:1 both in my motocross bikes and now chainsaws.. brapp
View attachment 917756

Black on white. Low number.

expert?

braaaap!

 

[holeycow]

I fouled a sparkplug once with a pack of coyotes not far behind me. I learned to change the plug before every ride.

For whatever reason would you be worried about some coyotes?

 

[Bob Hedgecutter]

For whatever reason would you be worried about some coyotes?

That might depend on the Coyote being hairy and four legged....... or if it was a metaphor for the trailing pack of riders looking to steal first place from Wonder Bill?

 

[Huskybill]

We were just trail riding with Freinds and family. I never raced. I helped the kid.

You wouldn’t worry about a pack of yokes coming your way?

 

[holeycow]

No. I chase them, they don't chase me. They are pretty low in the heirarchy here, what with the wolves and the bears and the cats...

And yes I have literally chased them through the woods unarmed while they were after my silly dog. More than once. Silly dog.

with wifey two of those times, her chasing too.

anyway, you don't get chased by a pack of coyotes around here.