I have decided to go with the 100 octane low lead Aviation gas for my chainsaw and other yard equipment (trimmer, hedge trimmer, mower, etc). All of the gasoline available around here is required to have 10 percent ethanol in it and I do not want to use it anymore due to the poor shelf life and possible damage it can do to my equipment. The local airport has the 100LL gas and its easy to get and does not cost that much more than regular gasoline. My question is.... do I need to re-tune the carburetors on all of my stuff in order to run this fuel? I just filled up the tank on my husky 455 and It seemed to be fine, possibly idles a little differently but I did not notice any performance changes right away. I do not really have any experience tuning carburetors and my husky dealer already had my saw setup before I took it home. With running this aviation fuel do I risk doing any damage to the saw without having it specifically tuned for it?
100LL AV Gas, adjust carb necessary?
- Thread starter TommyGun
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Absolutely, you will need to retune both the L and H sides.
J.W Younger
ass kissing impaired
i change the settings just due to weather conditions so thats no big deal. my leaf blower(reed valve) seems to really like the avgas but chainsaws not so much
wigglesworth
Booned
I run 100LL in all my saws. And yes, you have to adjust it.
J.W Younger
ass kissing impaired
I,m thinking the SG of avgas is real close to what pump gas averages but the burning rate may be a little slower. If this is the case it won,t hurt anything but leaning a tad may help throttle response.
Ok.... any tips on how to adjust a carburetor? I know where the adjustments are and such, I also have a workshop manual that shows what they do, but whats the process for correctly adjusting a carburetor? Id like to be able to do this on my own just in case I switch back to regular gas down the road.
J.W Younger
ass kissing impaired
rt, (clockwise) leans, lt (ccw) richens. 1/8 turn is a bunch so don,t get carried away.
Banshee
Addicted to ArboristSite
You can run 100ll on a saw set up for pump without harm. It will run rich though and not give you it's best performance. But you don't want to run pump on it if it's set up for AV. It will run lean.
I can't really see a differance in performance with 100 but the shelf life more than makes it worth it.
I've been reading a lot about how 100ll doesn't idle as well, but who cuts at idle?
I can't really see a differance in performance with 100 but the shelf life more than makes it worth it.
I've been reading a lot about how 100ll doesn't idle as well, but who cuts at idle?
yo2001
ArboristSite Operative
I think since the 100LL is slower burning fuel, it take little bit more timing to get complete combustion. It'll be more noticeable at idle becase of the lower volume effieciency.
To take full advantage of higher octane fuel, you would want more timing. That'll give you more trust leverage (leverage=torque) at the same time, you would have more complete combustion since you are starting an ignition earlier. Plus, higher the octane, less likely to detonate the end gas.
Nitroman
Addicted to ArboristSite
Your owners manual should have a section on how to tune the carb. If you really want to fine-tune it, get a little tach from Bailey's.
I like to tune my saws when the weather changes; temperature and humidity can make a surprising difference. Changing fuel would be a factor in tuning the carb. It isn't a big deal. I have to disagree with changing the timing for homeowner use, but then, I disagree with quite a few things other forumites say about avgas.
But that is me, your mileage may vary.
Also just the fact your saw is an expensive tool that if maintained properly, will last for years (if not a pro-logger), and part of that maintenance is setting the saw up for the conditions. It only takes the time to warm up the saw while getting on the chaps and checking things out, then tune the carb; good to go.
I like to tune my saws when the weather changes; temperature and humidity can make a surprising difference. Changing fuel would be a factor in tuning the carb. It isn't a big deal. I have to disagree with changing the timing for homeowner use, but then, I disagree with quite a few things other forumites say about avgas.
But that is me, your mileage may vary.Also just the fact your saw is an expensive tool that if maintained properly, will last for years (if not a pro-logger), and part of that maintenance is setting the saw up for the conditions. It only takes the time to warm up the saw while getting on the chaps and checking things out, then tune the carb; good to go.
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Smokerr
ArboristSite Operative
You are moving from a gasoline that has NO lead, to a gasoline that has a lot of lead.
Your saw will be designed to deal with the ethanol, and your saw oil has preservatives in it.
Stay with the gasoline.
Your saw will be designed to deal with the ethanol, and your saw oil has preservatives in it.
Stay with the gasoline.
wigglesworth
Booned
Yes it has a very small amount of lead, but lead lubricates, I cant imagine it hurting it, unless it built up, which I have not experienced.
Do a search for "ethanol". Most people report problems due to ethanol, such as smoked top ends, water in fuel, dried up carb gaskets, etc. etc. Ethanol=Bad for your saw.
See... this is where my dilemma is. I have no choice locally but to purchase either the 100LL at the local airport, OR pump gas which is required by Missouri law to have 10 percent ethanol in it. I have read more negative about ethanol than 100LL which is why I decided to go and purchase some. I have not really ran the saw with the aviation fuel yet. I don't do a huge amount of cutting, therefore I would also like to be able to use a fuel that won't go bad within a month or 2. I have never had any problems with ethanol, but I have heard plenty of horror stories and do not want to ruin my equipment. Regular 91 octane pump gas with no bull#### additives would be great if I could find it.....
Just use pump gas. I doubt you're going to have problems with 1-2 month old fuel.
If you have access to reasonably priced 100LL,I'd take any day that over any type of ethanol fuel.Two problems with pump gas are shelf life and alcohol.No problem with the AVgas.My dealer sells 100LL and tunes all his saws for it.Mine runs great great on it.(Dolmar 5100s) Ron
billyjoejr
ArboristSite Guru
oneoldbanjo
Addicted to ArboristSite
Motodeficient
ArboristSite Guru
I have an MS361 that was ported and muffler modded by Brad. I have been using 91 octane pump gas that has the 10% ethonal. I work at an airport so I have easy access to 100LL. Should I switch, or just keep using the pump gas?
smokinj
Addicted to ArboristSite
I would stick with pump its much cheeper
