is my saw irreparable?

[ArborSharp]

I knew I had mixed my fuel a little bit lean, 2.6 oz to maybe 1.25 gal, but was out of mix and made a few cuts trying to finish up a job.

next day temperatures in the single digits, I added mix to the fuel, making it a little rich. the saw ran for a while, then I had trouble starting it and then would not start at all (heard a pop then the sound when I pulled the pull cord changed)

I open it up and it almost seems like the spark plug was pushed out, screwed up the the threads (see pic)

this is a homeowner saw that I have put through quite a few hours of commercial work, kicking myself for pushing it while a little lean. is this thing toast?

 

[Frankie]

Can be repaired

 

[lumberjack]

Welcome to the forum, @ArborSharp !

Not a big deal to fix, this is what you want Thread Repair Kit

 

[Nutball]

Looks like the plug got loose and ran that way for a while allowing vibration to destroy the threads. Fixable.

As for oil: more oil in the gas will make the saw run leaner, less will make it run richer, also cold weather makes them run leaner and warm weather makes them run richer. It's best to stick to 40:1 all the time for longevity, and tune the carb a little richer in cold weather below 30-40 degrees.

 

[Bermy]

Umm... rich or lean is to do with air/fuel mix, not oil/fuel mix, or am I missing something in your reasoning?
As long as my carb air, fuel settings are correct a bit more oil in my gas will only serve to make the saw boggy and foul the plug

 

[Altissimus]

True that on terminology Fiona ... Only once I had a plug loosen and back itself out then saw no run. No thread damage though. Also if worried about potential wear or damage from too little mix oil it probably wouldn't be at the plug but scoring cylinder walls , you can peek with a flashlight while the plug is still out.

 

[treesmith]

Welcome to the forum, @ArborSharp !

Not a big deal to fix, this is what you want Thread Repair Kit

Hard to believe someone would do that to a saw....of all the careless things....

 

[Frankie]

It's best to stick to 40:1 all the time for longevity, and tune the carb a little richer in cold weather below 30-40 degrees.

Haha ... complete rubbish ! ALL manufacturers recommend 50:1 using THEIR mix oils ... EVERY ... SINGLE ... ONE ! I’ve put hundreds of hours on saws and torn them apart and everything was well lubed and clean with exception of some carbon buildup on piston. The high compression 2-stroke , gotta “machine” the cylinder crowd advocates 32 or 40 to 1 because they KNOW that the increased heat created and produced , coupled with the hammering the crap out of the bottom end (yeah nutball this is unavoidable when you take the compression from stock 155psi up to 200+psi) requires more oil ! Trouble is (and I’ve tried 40:1) you have to RUN THE PISS outta the saw otherwise you will carbon the heck outta the engine- and now the longevity will be LESS than if ya just used 50:1 from the get go - a piece of carbon flakes off and bye-bye topend ... Use the best gas / mix you can (motomix is great) and follow the manufacturer’s recommended maintenance and you should enjoy 1000-2000hrs of operation on a pro saw ... That’s the FACT JACK

 

[Frankie]

Umm... rich or lean is to do with air/fuel mix, not oil/fuel mix, or am I missing something in your reasoning?
As long as my carb air, fuel settings are correct a bit more oil in my gas will only serve to make the saw boggy and foul the plug

A gallon is 128 Oz .... at 50:1 the amount of oil used is 2.56oz per gal - at 40:1 the amount of oil used is 3.2oz per gal or approximately .64oz of oil per gal more at 40:1 than 50:1 ... If you are running an mtronic or autotune stay with 50:1 despite what nutball insists, there are reasons why. I find it humorous that some individuals think they are smarter / more clever than the engineers from Stuttgart and Stockholm - rest assured , they are not!

 

[Bermy]

50:1 here all day. Measured and mixed a litre at a time and decanted into my every day 5l combi can.
Sometimes when measuring either the oil or the gas I get it a wee bit wrong, but I'd rather have the mix a bit too oily than not enough. It just means my mix is too oily, the saw will smoke more, be boggy on pickup and foul the plug, and that's only if it's waayy to oily,
Just a smidge more makes no never mind in the long run.

 

[Nutball]

Haha ... complete rubbish ! ALL manufacturers recommend 50:1 using THEIR mix oils ... EVERY ... SINGLE ... ONE ! I’ve put hundreds of hours on saws and torn them apart and everything was well lubed and clean with exception of some carbon buildup on piston. The high compression 2-stroke , gotta “machine” the cylinder crowd advocates 32 or 40 to 1 because they KNOW that the increased heat created and produced , coupled with the hammering the crap out of the bottom end (yeah nutball this is unavoidable when you take the compression from stock 155psi up to 200+psi) requires more oil ! Trouble is (and I’ve tried 40:1) you have to RUN THE PISS outta the saw otherwise you will carbon the heck outta the engine- and now the longevity will be LESS than if ya just used 50:1 from the get go - a piece of carbon flakes off and bye-bye topend ... Use the best gas / mix you can (motomix is great) and follow the manufacturer’s recommended maintenance and you should enjoy 1000-2000hrs of operation on a pro saw ... That’s the FACT JACK

They recommend 50:1 for emissions reasons. 50:1 offers little extra protection against harsh conditions. Carbon will depend on the gas, the carb setting, and what oil you use. I have seen engines run cleaner with more oil, but I think it is more of a heat thing. Run hot, and the oil can bake as carbon on depending on what kind of oil. Tuned right will help keep excess carbon burned off.

As for tuning: If you have more parts oil in your gas and the carb only flows a fixed amount dependent on the needle setting, then less gas gets through and more oil. Less oil means more gas gets through. That changes the fuel/air mix. Take a leaf blower, run it on 50:1, then try 20:1, then try 300:1. You will notice a difference. It will be too lean to run on 20:1, and will run rich on 300:1.

I have not heard of loggers getting overall fewer hours out of high compression saws.

 

[lumberjack]

I'm crazy in that I'll put 2 gallons of whatever regular gas is available at the station I'm at, a 2.5 gallon oil mix bottle, and just run the saws... hardly ever have a stitch of trouble aside from occasionally running one over. @treesmith was running the Masterminded 461 when it spit the spark plug out, don't know why he can't take care of my stuff...

 

[Frankie]

50:1 is what is recommended in the manual that comes with STIHL and Husqvarna Saws I own. The advances in oil tech have come a loooong way and 50:1 synthetic oil with a spot on tune will provide the end user with 1000-2000hrs of use providing a sharp chain is used and recommended maintenance performed. If you are concerned about “harsh conditions” then run 50:1 and a little fat on the high-idle - that’ll give her a tad more mix and let her run at a cooler temp .... I can tear down a saw run on 50:1 Motomix that has over 500hrs on it and aside from some carbon on the piston crown (which is normal) the bearings, bore piston etc are in like new condition, Oil HOLDS HEAT bro , it’s simple physics that cannot be denied ... If YOU choose to run 40:1 or 20:1 in YOUR saws then knock yourself out - especially if you want to kill mosquitoes and breathe toxic fumes 😂 . There are people here on this forum who have been running saws longer than you have been alive son , so give it a rest already. I’ve heard of plenty of loggers not getting 3months out of high-compression “machined” saws and plenty that have blown up in less than 50 tanks of fuel! When you up the compression excessively you put more stress on the bottom end , again simple physics that cannot be denied, I’ve even seen the castings crack at the base from excessive “machining” BIG difference between comparing 40:1 and 50:1 and throwing in 300:1 bro .... let’s keep it real ok ?

 

[lumberjack]

I'm interested in the simple physics of "oil holds heat" in this context.

 

[Pelorus]

I'm curious why Stihl recommended 40:1 for years and then switched to 50:1 using the same oil. I believe it has to do with emissions not carbon build up.
I'm still mixing @ 40:1 using premium ethanol free gas and have had zero issues with saws conking out.
@ Frankie: if you were running a MS880 with an Alaskan Mill, would you honestly mix 50:1?

 

[lxskllr]

I'm somewhere between 40-50:1. I measure 40:1, but I don't rinse the container, or let every last drop drip out, so it's probably ~44:1 mixed.

 

[Nutball]

I'm crazy in that I'll put 2 gallons of whatever regular gas is available at the station I'm at, a 2.5 gallon oil mix bottle, and just run the saws... hardly ever have a stitch of trouble aside from occasionally running one over. @treesmith was running the Masterminded 461 when it spit the spark plug out, don't know why he can't take care of my stuff...

It's usually not a big deal, but something to keep in mind. I worked with some guys who didn't know much, and they were filling the trucks, and one guy decided to top off the 4-5gal saw gas can. I tried to stop him, but he wouldn't listen and poured a whole bottle of oil in and already 1/3 full can. He said more oil won't hurt anything. That day I had to use the power pruner at full length all day, which wasn't pleasant because it had stalling issues the whole time since it was too lean to idle very long and couldn't run full throttle.

 

[BIGTWIG]

Haha ... complete rubbish ! ALL manufacturers recommend 50:1 using THEIR mix oils ... EVERY ... SINGLE ... ONE ! I’ve put hundreds of hours on saws and torn them apart and everything was well lubed and clean with exception of some carbon buildup on piston. The high compression 2-stroke , gotta “machine” the cylinder crowd advocates 32 or 40 to 1 because they KNOW that the increased heat created and produced , coupled with the hammering the crap out of the bottom end (yeah nutball this is unavoidable when you take the compression from stock 155psi up to 200+psi) requires more oil ! Trouble is (and I’ve tried 40:1) you have to RUN THE PISS outta the saw otherwise you will carbon the heck outta the engine- and now the longevity will be LESS than if ya just used 50:1 from the get go - a piece of carbon flakes off and bye-bye topend ... Use the best gas / mix you can (motomix is great) and follow the manufacturer’s recommended maintenance and you should enjoy 1000-2000hrs of operation on a pro saw ... That’s the FACT JACK

How else would one run a chainsaw?

 

[Frankie]

I'm curious why Stihl recommended 40:1 for years and then switched to 50:1 using the same oil. I believe it has to do with emissions not carbon build up.
I'm still mixing @ 40:1 using premium ethanol free gas and have had zero issues with saws conking out.
@ Frankie: if you were running a MS880 with an Alaskan Mill, would you honestly mix 50:1?

Milling is a different ball of wax ... IF you are running the snot out of the saw a “torque port” and 40:1 ain’t gonna hurt the saw ... Remember you are taking looooong extended full throttle cuts when milling - much moreso than a 10-20 sec cut when bucking or limbing with a rest in between ... My dirt bikes called for 20:1 way back in the day. Now they call for 32:1 to 40:1. Advances in synthetic mix oil are responsible for the change. The engineers at Stuttgart and Stockholm spend millions on R+D

 

[Frankie]

How else would one run a chainsaw?

Big difference between chainsaw milling (running the piss outta the saw - full throttle long extended cut time) and limbing and bucking where you are making cuts intermittently and not on the throttle continuously

 

[ArborSharp]

Thanks for the counsel and the welcome! I will look into thread repair. maybe I can get some more life outta my late gpa's saw after all
And for the correction about terminology- I probably just heard someone whom I considered more experienced use lean/righ to describe oil mix. I saw another forum in which a respondent suggested just using the word 'ratio' to describe the mix.

 

[Al Smith]

I'm old school and use 32 to 1 ratio and have never had a problem with carbon or fouling a sparkplug .You could run 16 to 1 and all it would do is smoke like it's burning soft coal .Those old outboard boat motors ran on 16 to one for decades with no problems .The only problem they ever had was running at trolling speeds for long periods which could foul the plugs .Simple enough, pull the lines ,lean it out and run the pizz out of it then get back to trolling .

 

[Frankie]

Fuel cools , oil lubes -gasoline will produce more power per ounce than oil and cools the top of the piston . The service manual recommends 50:1 on my STIHLS and Husqvarnas. These are modern hi-performance chainsaws , not Pullins from 1970s era. Too much oil will bite you in the ass down the road using mtronic/autotune strato “controlled air leak” saws . Besides what have ya got against mosquitoes 🦟 ?