High RPM chainsaws

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hemlock

Feeling the Heat
May 6, 2009
455
east coast canada
Hello,
I am wondering about newer high RPM chainsaws. Does anyone have any concern that they may wear down quicker (rings), or throw a bearing faster than "older saws". I speak from seeing a new Dolmar 5100s, and a 346xp in action. Very impressive, but left me wondering what was sacraficed to get these new "screamers". I know technology changes, but still, a two stroke is a two stroke. High RPM = High heat. I may be way off as well. Wouldn't be the first time....


Husky 137
Husky 50
Husky 262xp
McCulloch PM 10-10 (RIP)
 
5100 runs at 15,500 they dont have any issue that i know of and i run my stihls at 14,200rpm 96 octan no issues, doent run any hotter than the old ones
 
smokinj said:
5100 runs at 15,500 they dont have any issue that i know of and i run my stihls at 14,200rpm 96 octan no issues, doent run any hotter than the old ones

where are you getting 95 octain and is is corn free??? is it expensive, i have to get my saws off ethanal
 
CTBurner said:
smokinj said:
5100 runs at 15,500 they dont have any issue that i know of and i run my stihls at 14,200rpm 96 octan no issues, doent run any hotter than the old ones

where are you getting 95 octain and is is corn free??? is it expensive, i have to get my saws off ethanal
I buy 93 octane and put some octane boost in with it corn free!
 
What could I safely run at 262xp at, RPM wise? Is it a carb adjustment that would have to be made?
 
catfish said:
What could I safely run at 262xp at, RPM wise? Is it a carb adjustment that would have to be made?
with a muffler mod you can get about 1000 more rpm's over stock
 
in theory probably shorter life span in hours, as ring life in miles or whatever is reached sooner.
in reality, so much better oils now theylast so much longer.
and the amount of wood cut per day, or per lifespan of the machine, is so much more.
Lighter, higher rpm, better chains, higher productivity.


there were much better saws, made of rugged metal, but weighing 15 and 20 lbs. and they cost a months wages. Now, a good pro saw is a weeks wages. And there is the choice of a days wages for a box store plastic junky saw. So not fair to compare a metal mac of a months wages with a plastic Home Dep saw really cheap.

the 'good old days' were better in memory than in reality maybe....
I am very thankful for the better technology, especially with age. I appreciate light weight, better AV, better mufflers, less smoke, and more 'fun factor' to get the job done.

k
 
I buy 93 octane and put some octane boost in with it corn free![/quote]

What is the purpose of adding octane boost to your fuel? It does not have any more power with octane booster added to it.
 
svannoni said:
I buy 93 octane and put some octane boost in with it corn free!

What is the purpose of adding octane boost to your fuel? It does not have any more power with octane booster added to it.[/quote]
chainsaw will run better at higher octanes less bogging and quicker starts and it just smells good!
 
If it is worth the cost to you to make it smell good that is your choice. However the higher the octane the fuel has the slower the fuel burns. It has no more power potential just the speed of which it burns. As far as i know all chainsaws are 2 cycle so with mixed fuel I think any additive will just help the economy not your chainsaw.
 
smokinj said:
svannoni said:
What is the purpose of adding octane boost to your fuel? It does not have any more power with octane booster added to it.
chainsaw will run better at higher octanes less bogging and quicker starts and it just smells good!

You've been smoking too many j's. ;-)

Octane != power. Octane booster doesn't add power. Race fuel happens to have more power and a higher octane rating. Premium with ethanol has less power and a higher octane octane than regular without ethanol. There isn't a direct correlation between octane and power.
 
svannoni said:
If it is worth the cost to you to make it smell good that is your choice. However the higher the octane the fuel has the slower the fuel burns. It has no more power potential just the speed of which it burns. As far as i know all chainsaws are 2 cycle so with mixed fuel I think any additive will just help the economy not your chainsaw.

good for you bring your saw and put it in a 50-60 in silver maple and see witch gas can you start using not telling you to use it! But Iam telling you the proforamce is better in the large wood and thats what i cut! but if you say so i will go back to e 85 lol
 
smokinj said:
svannoni said:
If it is worth the cost to you to make it smell good that is your choice. However the higher the octane the fuel has the slower the fuel burns. It has no more power potential just the speed of which it burns. As far as i know all chainsaws are 2 cycle so with mixed fuel I think any additive will just help the economy not your chainsaw.

good for you bring your saw and put it in a 50-60 in silver maple and see witch gas can you start using not telling you to use it! But Iam telling you the proforamce is better in the large wood and thats what i cut! but if you say so i will go back to e 85 lol

Don't get me wrong. Ethanol is the wrong way to go. A quality standard fuel is the way to go. There is just not the need for the octane boost. High octane fuel should only be needed if you have a high compression engine. Since the is not a hotsaw forum I assume you have a stock saw. Plus the oil you are mixing with your fuel is all the octane boost you need. Since it is slowing the burn time of your fuel.
 
svannoni said:
smokinj said:
svannoni said:
If it is worth the cost to you to make it smell good that is your choice. However the higher the octane the fuel has the slower the fuel burns. It has no more power potential just the speed of which it burns. As far as i know all chainsaws are 2 cycle so with mixed fuel I think any additive will just help the economy not your chainsaw.

good for you bring your saw and put it in a 50-60 in silver maple and see witch gas can you start using not telling you to use it! But Iam telling you the proforamce is better in the large wood and thats what i cut! but if you say so i will go back to e 85 lol

Don't get me wrong. Ethanol is the wrong way to go. A quality standard fuel is the way to go. There is just not the need for the octane boost. High octane fuel should only be needed if you have a high compression engine. Since the is not a hotsaw forum I assume you have a stock saw. Plus the oil you are mixing with your fuel is all the octane boost you need. Since it is slowing the burn time of your fuel.

you assume too much!
 
smokinj said:
svannoni said:
smokinj said:
svannoni said:
If it is worth the cost to you to make it smell good that is your choice. However the higher the octane the fuel has the slower the fuel burns. It has no more power potential just the speed of which it burns. As far as i know all chainsaws are 2 cycle so with mixed fuel I think any additive will just help the economy not your chainsaw.

good for you bring your saw and put it in a 50-60 in silver maple and see witch gas can you start using not telling you to use it! But Iam telling you the proforamce is better in the large wood and thats what i cut! but if you say so i will go back to e 85 lol

Don't get me wrong. Ethanol is the wrong way to go. A quality standard fuel is the way to go. There is just not the need for the octane boost. High octane fuel should only be needed if you have a high compression engine. Since the is not a hotsaw forum I assume you have a stock saw. Plus the oil you are mixing with your fuel is all the octane boost you need. Since it is slowing the burn time of your fuel.

you assume too much!

Your right I do assume too much. And also I did just notice in your list of saws does indicate a ms 460 ported. That does indicate you do not have a stock was. However porting has and extremely minimal effect to compression. Porting increases volumetric efficiency. The only was it can increase compression is through the supercharging effect. If it was truly a hot saw that would require high octane fuel would would not be dropping trees with it. And if you are then you have enough extra money to continue to stimulate the economy for the rest of us.
 
svannoni said:
smokinj said:
svannoni said:
smokinj said:
svannoni said:
If it is worth the cost to you to make it smell good that is your choice. However the higher the octane the fuel has the slower the fuel burns. It has no more power potential just the speed of which it burns. As far as i know all chainsaws are 2 cycle so with mixed fuel I think any additive will just help the economy not your chainsaw.

good for you bring your saw and put it in a 50-60 in silver maple and see witch gas can you start using not telling you to use it! But Iam telling you the proforamce is better in the large wood and thats what i cut! but if you say so i will go back to e 85 lol

Don't get me wrong. Ethanol is the wrong way to go. A quality standard fuel is the way to go. There is just not the need for the octane boost. High octane fuel should only be needed if you have a high compression engine. Since the is not a hotsaw forum I assume you have a stock saw. Plus the oil you are mixing with your fuel is all the octane boost you need. Since it is slowing the burn time of your fuel.

you assume too much!

Your right I do assume too much. And also I did just notice in your list of saws does indicate a ms 460 ported. That does indicate you do not have a stock was. However porting has and extremely minimal effect to compression. Porting increases volumetric efficiency. The only was it can increase compression is through the supercharging effect. If it was truly a hot saw that would require high octane fuel would would not be dropping trees with it. And if you are then you have enough extra money to continue to stimulate the economy for the rest of us.
lol your funny assumeing again! your right with the picture your painting but porting the saw also meens the squish has been done ("that would be assuming") your already there so finish the job right!
 
My Stihl recommended mid grade 89 octane gas. Octane doesn't give you power it allows you to tune your saw to make more power by slowing combustion. Adding high octane fuel to an engine that was optimized for low octane fuel will not creat more power and might even reduce power. Still I use premium fuel with 93 octane in all of my small equipment so since the premium fuel should be of higher quality. Hard to say.

I could even buy race gas not for the octane but so that I get non-ethanol fuel of good quality.
 
Highbeam said:
My Stihl recommended mid grade 89 octane gas. Octane doesn't give you power it allows you to tune your saw to make more power by slowing combustion. Adding high octane fuel to an engine that was optimized for low octane fuel will not creat more power and might even reduce power. Still I use premium fuel with 93 octane in all of my small equipment so since the premium fuel should be of higher quality. Hard to say.

I could even buy race gas not for the octane but so that I get non-ethanol fuel of good quality.

well said the set up I have with my 460 octane will make a big differnce mainly in big wood where you have a 28 in. bar beaver tailed for 4-5 mins. the name of the tread is "High RPM chainsaws" I am set to run 14,200 rpms ported intake ported exhaust squish if i can rember right .006 and 3/4 in muffler port octane helps.......... stanard modd. 460 work saw
 
It is becoming evident with what you are telling all of us that you have one hopped up saw. It is also becoming clear your saw does not run like it should on 93 pump gas. To a simple minded guy like me this says either you should be running race fuel and not the oxygenated tree hugger fuel you get from the pump or you need to have your carb tuned correctly. Likely the carb will have to be tuned several times a year due to the season changes. A small price to pay for such a highly modified piece of engineering.
 
svannoni said:
It is becoming evident with what you are telling all of us that you have one hopped up saw. It is also becoming clear your saw does not run like it should on 93 pump gas. To a simple minded guy like me this says either you should be running race fuel and not the oxygenated tree hugger fuel you get from the pump or you need to have your carb tuned correctly. Likely the carb will have to be tuned several times a year due to the season changes. A small price to pay for such a highly modified piece of engineering.
wrong on all accounts when the bar is barried it just runs better with higher octane hopped up not really.Tuning no problem i tune by ear in and out of the wood runs fine on 93 and idles fine! point is you can run stronger in the big cuts atleast with my saw with a little higer octane 96 seems to be the sweet spot if you will. 4 hrs. cutting with the bar barried is normal for me! Its like driving up a mountain with a heavy load higher octane helps
 
I dont know either of you guy's or what you know about engine's and fuel. That said "race gas" has many additives to improve pawer, however Octane is not one of them it's ONLY purpose is to reduse or eliminate denotation which is when the fuel ignites at the less than optimum time," Kind of like the ignition timing being off in your car and you hear that pingging noise" and can and will have catistrofic results including eroding holes in top of pistons. Now when you start hot roddin any engine two or four stroke. i.e. Bumpin up compression, cams, porting, intake and exhaust. the engine will have a tendency to detonate, then you start adding octane to counteract all the work you have done.
 
svannoni said:
It is becoming evident with what you are telling all of us that you have one hopped up saw. It is also becoming clear your saw does not run like it should on 93 pump gas. To a simple minded guy like me this says either you should be running race fuel and not the oxygenated tree hugger fuel you get from the pump or you need to have your carb tuned correctly. Likely the carb will have to be tuned several times a year due to the season changes. A small price to pay for such a highly modified piece of engineering.
Actually alot of race fuel is oxygenated http://www.vpracingfuels.com/index.asp :coolsmirk:
 
It is safe to say I am fairly competent with internal combustion engines. I did also now there are so race fuel suppliers going into oxygenated fuels. This is for the street legal racers out there from what I understand. I also no there are a lot of additive in race fuel most of which is not just octane boost. As I stated before I think the 2 cycle oil would act like and octane boost by slowing the furn time. To what extent I am not sure of but I'm sure it would be plenty. In my opinion if you modify an engine my porting and milling heads to increase compression ratio the fuel system needs to be retuned. Most likely a bump in jet size and not just twisting on some idle bleed screws. If smokinj's saw runs better with octane boost in it I don't think it is due to it too low of octane. It is more likely running too lean.
 
:bug:
svannoni said:
It is safe to say I am fairly competent with internal combustion engines. I did also now there are so race fuel suppliers going into oxygenated fuels. This is for the street legal racers out there from what I understand. I also no there are a lot of additive in race fuel most of which is not just octane boost. As I stated before I think the 2 cycle oil would act like and octane boost by slowing the furn time. To what extent I am not sure of but I'm sure it would be plenty. In my opinion if you modify an engine my porting and milling heads to increase compression ratio the fuel system needs to be retuned. Most likely a bump in jet size and not just twisting on some idle bleed screws. If smokinj's saw runs better with octane boost in it I don't think it is due to it too low of octane. It is more likely running too lean.
Sorry if I came off wrong wasnt trying to,Dont 2 strokes have a tendency to "run away" when they get leaned out? Have had it happen to me twice once in a sea-doo and once in a 6-71 detroit<that one was scarry :eek:hh:
 
ok again I dont want to tell anyone how to run there saw but when under heavy loads were not talking 8x8's 10x10 or 12x12's were talking 55x55 log's you may know more about engines then I will ever know and I am fine with that but my saw is not running lean or anything else that you may be trying to think might be going on(TO RUN THIS SAW LEAN WOULD BE IN THE 15000 RPM RANGE) !!!!!!!!!! when racing a saw everyone must use 93 octane out of one can there is a reason why they do this so no one gets an edge. there is other ways to get more proforamce out of the fuel as well sure not going there with this bunch. There is always something you can learn every day.Toulene is whats in the octane boost that gives you the power the higher octane is just a by product. If your not running a high rpm saw (13500-15500) in big wood this is hard to know but you pick up things along the way. 2 things when cutting a 55x55 14ft to 16 ft 18in's. cuts then 1/4 each piece your going to be thinking one of two things I will never pick up a saw again or how can I make more power!!!!!!! If you want to try to see a differce octane will make use 2 gallons of 87 (in your saw)then switch to 93 you will tell a differnce again "high rpm saws in heavy load"
 
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