echo heats up?

[cjrenegade82]

i have an echo cs520 that gets real hot when i run it and im not sure y
im running the carb a little rich because of that didnt help much
useing echo 2cycle 50 to 1 poulan bar oil as much as i can get on there so i still run out of gas first i tryed a heavier oil echo and stihl didnt notice a differance the chain brake dosent seem to be dragging the clutch could be slipping not sure how to tell if its not real bad but the saw is a year old not to much use 50hrs or so i clean everything off blow any dust out of it after every use. spark plug looks good gapped to spec clean air filter gease spocket often
chains are sharp stock saw except no screen in exhaust. saw is now running at 12000 rpms after carb adjust iv been cutting mixed hardwoods
maybe this saw just runs hot i dont know but is too hot for my liking
any thoughts would be much appreciated thanks

 

[Brushwacker]

If the timing was retarded it could cause it to run hot. May check the flywheel key and be sure the the flywheel hasn't slipped. If the nut was loose it could lead to the problem.
Make sure your muffler is not loose and the gasket is not leaking. Last summer a 385 xp seized on my freind and the exhaust was loose. Nothing else was found that could have caused the seizure. We were cutting large stumps and noted it was hot but stopped to late.
Premium gas and a good oil and mix ratio and proper carb adj. to your mix should fulfill a not to hot running saw.

 

[treemandan]

clean the fins and air flow around motor?

 

[cjrenegade82]

the gasket on the muffler is split and could be leaking but i did not know it could cause excess heat and did not even think about the timing
tomarrow i will check the key and order a new gasket

i have been playing with the carb alittle to try to correct it but i dont know much about tunning them and dont have a tach i checked it before at a shop.
when running it before at 12000 it was running to rich so i leaned back out alittle. So any advice on adjusting the carb would be appreciated

i do keep the fins on the engine and fly wheel clean as well as the rest of the inside of the case as well as i can without tearing everything apart

i also recently noticed that half of the spark plug was black and the other half looked good i have never seen that before and cant imagine what could cause it

Thanks for the help

 

[Brushwacker]

the gasket on the muffler is split and could be leaking but i did not know it could cause excess heat and did not even think about the timing
tomarrow i will check the key and order a new gasket

i have been playing with the carb alittle to try to correct it but i dont know much about tunning them and dont have a tach i checked it before at a shop.
when running it before at 12000 it was running to rich so i leaned back out alittle. So any advice on adjusting the carb would be appreciated

i do keep the fins on the engine and fly wheel clean as well as the rest of the inside of the case as well as i can without tearing everything apart

i also recently noticed that half of the spark plug was black and the other half looked good i have never seen that before and cant imagine what could cause it

Thanks for the help

Sounds like your on the right track to me. Heat from the exhaust leaking could be most of the problem. Additionaly the engine would run leaner burning hotter. I would check the flywheel still though. If the flywheel nut is tight it is more likely the flywheel did not move therefore it may not be necessary to pull it. I wouldn't risk breaking anything to take it off if I didn't have the right tools. If the gasket doesn't cure it you can go back and get it off to check the key closer later.
I don't know for sure why the plug color although I've seen that myself and assumed the low carb adjustment being rich could of caused the dark side when the saw was idling.
Do a search for carb adjustment . There was a link that had the procedure explained. If your not confident your doing it right better have it done by somebody that knows how rather risk running it lean and causing engine damage.

 

[cjrenegade82]

i checked the fly wheel bolt its tight and has paint from factory on it showing no movement put a new ngk plug in it last one was champion

waiting for gasket

looked for info on cab adjust found some good info but nothing about my specific saw just older evl or small top handles

i know some basics about adjusting carbs but im going to keep looking for some saw specific info

 

[Brushwacker]

Follow all safetey procedures when operating a chainsaw as specified by a professional source such as the saw manufactor.Nothing I do supercedes the manufactors guidelines and I reccomend you use their current guidelines for safety .Don't let the saw race wildly or hold it wide open out of the cut for a extended amount of time. I am just printing how I do it to compare notes. The way I adjust I start with 1 turn out unless I see it specified differant,sometimes on the saw near the adjustments or in a manual.With a clean air cleaner I warm the saw up in some wood, then starting with the low screw I adjust it each direction listening for the highest idle speed,I set it there and adjust the idle screw where the saw idles comfortably with out the chain turning. I usually repeat the adjustment over after I set the idle speed and again after setting the high speed screw. After initial low speed adjustment and idle with the chain + bar properly adjusted on the saw, , I listen to the saw at wide open a few seconds at a time and adjust the h screw out until it sounds like a burble when wide open out of the cut, and remember the position of the screw. From there I adjust it in until rpms start peaking or I notice it racing as it idles back down whichever comes first ( a few seconds at a time ). From there I move the screw half way inbetween this position and the burble position. Then I listen for smooth acceleration and deacceleration and richen (counterclockwise) both screws about 1 tenth of a turn at a time until this is achieved and adust the idle as necessary.
I try to keep a small screw driver with when out cutting and if a saw doesn't sound good ( such as racing when deaccelrating,dogging out or whatever)I use it. If making long full cuts such as milling , cutting big stumps and logs the saw should be richened, (turned out) the the h screw until it just starts to burble at wide open. When starting the cut the saw rpms should smooth out in the cut the way I see it.
Of course if the saw will not run like it should do not use it until the problem is corrected or you risk wrecking the motor or if you do not know how a saw runs when in proper tune take it to a qualified person to do the fine tune. A tachometor is the standard procedure to final safe carb setting most normally done at a saw shop.

 

[cjrenegade82]

thanks alot for the information
im going to give it a try if i cant tell by the sound ill take it to the shop
thanks again

 

[Cliff R]

Adjust the low speed screw first, for the smoothest/fastest idle, redcue the engine rpm's so the chain isn't turning, then turn the mixture screw counterclockwise just a tad until the engine slows slightly. This will give it a slightly rich off idle, sort of like an accellerator pump, to keep the engine from hesitating. You should not need to re-adjust the low speed screw.

Set the high speed screw at WOT and no load, so that the engine is "four stroking". Just test it for a few seconds at time. Turn the high speed screw clockwise (lean) just a small amount at a time, and continue the WOT no-load test. If at any point the engine goes smooth and runs away, go back to the last adjustment where it was four stroking. Once you have determined the leanest setting the engine will tolerate without running away, do a few test cuts. If at any point, the engine goes lean, or looses power, richen up the high speed screw. It only takes a few cuts to determine the ideal settings. Any time you are in the cut and reduce the load, the engine should immediately start missing, or four stroking.

Never set the engine for maximum RPM's, or to any set "standard". Some of Echo's later models will have a rev-limiting module, which makes the engine start missing at really high rpm's. I'm not sure if the CS-520 has this part, but it can fool the tuner into thinking the high speed screw is set rich enough, when it is not.

The basic idea for carburetor tuning, is to set the low speed screw for best idle quality, just a tad rich, to avoid any hesitation/stumble when you hit the throttle quickly. The high speed screw is then set for best power in the cut without going lean. It is not uncommon to have to make very slight adjustments to the high speed screw in varying weather conditions. The DA, or density/altitude varies considerably from one season to the other. The saw engine, like any other engine, will respond well to more fuel, when temps are cooler and more oxygen is available, the incoming charge is denser, etc, and to less fuel when it's hot/humid outside.

Be aware that these adjustments are very slight deviations from your "standard" setting. If you find that you have to add a lot of fuel at any point, their may be dirt/debris/varnish in the fuel system reduce fuel delivery to the engines at full load.

It is ALWAYS best to er on the rich side, than to run the saw up near the point where it goes lean. The EGT's go incredibly high at that point, and can very quickly melt some aluminum over the piston ring on the exhaust side. I've purchased boat loads of used saws with this problem, which we have quickly repaired with a pocket knife and peice of auto body sandpaper!

One last note, the CS-520 may have a catalyst inside the muffler, as it is a later version of the CS-510? Our CS-360T had one, and it ran very hot. I cut the muffler in half and removed the catalyst, and opened up the ports some, then welded it back together. It not only quit running hot, it has at least 20 if no 30 percent more power!.......Cliff

 

[cjrenegade82]

thanks cliff that definitely helps
i think it does have the rev limiter and has been throwing me off
and i would like to remove the catalyst if it has one if it does it may have been the reason it seemed to run hotter than any other saw iv used

is there a way for me to know if it has before splitting the muffler and what it looks like once i do
as far as opening up the ports in the muffler what would u suggest
reaming out existing port or adding another hole
i would like to get everything i can out of this saw while still keeping it reliable for years to come so any other suggestions would be much appreciated
thank again

 

[Cliff R]

I could not tell by visual inspection that the CS-360T had a catalyst in the muffler. It was inside a separate chamber, and surrounded by circular metal shield, with two small exit "slits" in it. The muffler would NOT come apart, not matter how hard we tried, so I cut it apart with a very fine hacksaw blade, them MIG welded it back together after the modifications.

Opening up the muffler really helped the saw, more power at every rpm. I still do NOT like the rev limiting feature, but have learned to live with it. I make sure to set the high speed screw to four stroke just before where the rev limiter cuts in. The rev limiting device is not instantaneous, and will let the engine rev well past the set point for a few seconds, then bring it back down by causing it to miss-fire. Annoying to saw the least, but I'm sure it saves Echo many thousands of dollars in uneccessary repairs from folks setting them too lean......Cliff

 

[cjrenegade82]

what exactly do you mean by four stroking

 

[Cliff R]

A term used to describe when the engine reaches an rpm where it sounds like it is missing, or miss-firing. The ideal high speed mixture has the saw miss-firing at full throttle and no load. Basically it will be "4 stroking" just before the setting where the engine would run lean and over-rev without missing at all. When the engine sees a load, it should immediately smooth out, and may even speed up considerably in rpm's while in the cut. If/when the load is removed, it should go back into a condition where it appears to be miss-firing again. Setting the carburetor correctly ensures that the engine will get plenty of lubrication, and not over-rev, go lean, and possibly experience piston/ring/jug damage......Cliff

 

[cjrenegade82]

thats what i thought but wasnt sure thanks for clearing that up