Cleaned air filters and both were very dirty. #3. A reddit for all operators of chainsaws to post experience with tools, pictures of their new saws and old workhorses and any maintenance tips. When you start your chainsaw, the crankshaft spins, creating vacuum pressure on the carburetor, pulling the gas from the tank and into the combustion chamber where it mixes with air and ignites. A compression gauge is used to measure the compression of a chainsaw which works similarly to the tire gauge. Similarly, a 4-stroke engine needs 2 times more compression than a 2-stroke engine, around 180-210 PSI. Another big issue that causes too much high compression is the lack of oil in the starter system. Starting fluid will make the fuel more combustible and makes the process of clearing out the combustion chamber much quicker. We and our partners use cookies to Store and/or access information on a device. Sparkplug was correct but I think it was a little flooded. Now, how much compression the engine of a chainsaw needs depends upon its motor capacity and temperature. Make sure you have a gauge with a schrader valve right at the tip of the spark plug adapter or you will get a low reading every time. Not sure I would do it to a saw, but the engine is running at rather high rpm when the water is sprayed into the carb air inlet. Soaking in water will do nothing but rust things up . The engine must be up to operating temperature, spray a light stream of water into the engine carb air inlet and the cold water shocks the hot carbon and the carbon flakes off and blows out the exhaust pipe. You're familiar with how to start a stihl yes? If it does maybe it is plugged. You will notice the compression less. Have had it into dealer and nothing wrong with it and dealer said that from time to time they see saws come in with nothing wrong with them but have increased compression. Not sure I would do it to a saw, but the engine is running at rather high rpm when the water is sprayed into the carb air inlet. Oct 7, 2019 / Minimum compression for a Stihl 2 cycle #3 the actual numbers will vary from one tool to another Getting accurate numbers without special tools is quite difficult because of the small volumes. It would give you rusted bearings. Would not be afraid to do it to a 4, 6, or V-8. Make sure the keyway is lined up correctly and tighten the nut down good and tight. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright . If any of these components are worn or broken, the chain saw wont start even with fuel. Gas with ethanol also burns hotter than gasoline which can cause the engine to overheat and burn the plug electrodes. The saw runs and starts great. Winterize Your Pool Like a Pro: A Comprehensive Guide for Home owners. Get you some Sea Foam at the local auto parts store. When you start the chainsaw, it triggers the worm drive to engage the oiler to send oil through a port that releases onto the bar. There is no carbon build up and all looks like new. And some will have more. Carboned rings will decrease not increase compression. I have a MS250 that has come up on compression since new. In other words, the problem is in the trigger itself, not a. carb adjustment screw. NelsGarage will share the knowledge Ive gathered about different tools and give you tips to accomplish your DIY projects faster. A problem in the ignition system is likely to be the culprit when the chainsaw doesnt spark. NelsGarage.com All Rights Reserved 2021 Theme: Prefer by, Stihl Chainsaw Troubleshooting & How-to Guide. I changed to synthitic. I have a MS250 that has come up on compression since new. I have plenty of engines with REALLY low compression that I'll be glad to swap him. Are you sure the starter rope isn't a little too short? That is a high compression saw, pull the rope slowly until you feel resistance then give it a short quick pull. $75.00. Does the saw have a compression release? By accepting all cookies, you agree to our use of cookies to deliver and maintain our services and site, improve the quality of Reddit, personalize Reddit content and advertising, and measure the effectiveness of advertising. I was given (estate) a small McCulloch chain saw and it started and ran great. People sometimes try to cut down a tree that is too big for their chainsaw. Check the chain oiler and ensure it is functional. Remove the filter, engine control lever and Stihl carburetor. Little two stroke motors as on chainsaws have to have a lot of compression to make the needed power. Use of this Web site constitutes acceptance of our. I agree the saw runs great, but when your helping old men with ideas of their own its hard to say I wish I had 190 pounds of compression. Is the spark plug the correct one for the saw? You can check the compression by pulling the spark plug out and holding it in your hand. I pulled them over with plug out ,They seemed to pull normal and believe they were fuel locked. I would never put water in it! The first step is to remove the cover that covers the spark plug on your chainsaw. This site is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. in the, All Rights Reserved. By rejecting non-essential cookies, Reddit may still use certain cookies to ensure the proper functionality of our platform. Replace with a new starter house Problem 2: Damaged pulley system Solution: 1. A chainsaw with no spark will shut down suddenly or not start at all. I would suspect the timing is too early. Try it, it may just do the trick! To ensure correct functioning and to prevent excessive compression, you might have to repair worn-out parts with new ones. i have a ms 250. Turn the engine to get under the piston and blow the crankcase out. A chainsaw engine generates this compression through the explosion of the fuel in the combustion chamber and the movement of the crankcase. Any ideas? of compression. I would suspect the timing is too early. "name": "Yesterday's Tractor Co.", Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Temperature Of The Engine A heavy-duty engine gets hot faster and works better than a cold engine. Loosen the nuts holding the clutch cover and disconnect the chain shroud and remove the oil plate. If it is over loading on fuel the carb may need rebuilt to stop the diaphragm from leaking fuel into the cylinder after the saw is shut off. A 250 has a fair amount of compression for a smaller saw but not that bad. It can be from something as simple as starting the chainsaw wrongly to more severe issues like a damaged carburetor. This is because your oil is not rated to get to work at a low temperature. It is significantly tougher to pull over than an 024 or the new 241. Youll need to clean the cylinder and piston to fix this thoroughly. Get it ported and it brings it to another level. chain saw compression release mod. The engine must be up to operating temperature, spray a light stream of water into the engine carb air inlet and the cold water shocks the hot carbon and the carbon flakes off and blows out the exhaust pipe. No it wouldn't go straight to crankcase because you would spray a light mist through air intake with hot engine and let it run for a while after doing it.You might want to do it with screen removed from muffler. As a result of using bad fuel or leaving fuel in the chainsaw for a long time, the fuel evaporates and leaves behind a sticky substance that accumulates and clogged the carburetor. Friction is usually the cause of a rope failing to draw when it should. My one and only MS250 was a kicker to start it but that was the only problem. Carboned rings will decrease not increase compression. Do that to the starter side when you're looking at the starter assy. Press question mark to learn the rest of the keyboard shortcuts. ", You need to pull the exhaust to check that. Quoting Removed, click Modern View to see Don't put water in the saw-ever. If repeated cleaning does not fully unclog the carburetor, you will have to replace it. Quoting Removed, click Modern View to see That would be quite the trick to get the oil to separate out of the gas, LOL. Every chainsaw requires a specific amount of compression if this compression is more or less than the required amount, the engine will not be able to produce energy from the fuel source, and it will be exhausted faster. Check the saws exterior for loose bolts, nuts, and screws and tighten them with an adjustable wrench or screwdriver. When starting the motor when its col, you should engage the choke position to increase fuel intake and reduce air to allow the engine to start. Drain and discard the old fuel, mix new fuel and cycle oil in the ratio 50:1 in a container, shake it and then pour the mixture into the chainsaws fuel tank. It is typical for the Stihl chainsaw to develop some issues, and when this happens, some basic troubleshooting will help identify the source of the issue and solution to help it run smoothly. "dateModified": "2017-08-17", If you do not replace the starter spring on time, it will cause you to replace the whole starter assembly. Every chainsaw requires a different compression level according to its built-up and model number. Compression problems are usually due to an air leak in the engine, usually around the gaskets and seals of the crankshaft. Replaced the chain and did some serious cutting and was so pleased. Why is the Garage Door Opener Light Not Working? Remove the right side cover, bar, and chain. Thanks! Oct 24, 2011 / Chainsaw excessive compression #1 . idle. Save my name, email, and website in this browser for the next time I comment. Check for clogged shafts and jets, clogged carburetor, damaged valves, stuck levers, and damaged or warped diaphragms, all of which can interfere with the fueling process. Would have to remove spark plug and rinse cylinder with gas to be able to start. Don't put water into the 2 stroke. Pull the rope until it starts. The excess gas can be cleared simply by removing the plug and operating the starter a few times. To fix this problem, turn off the chain saw and let it sit for about 30 minutes to allow the excess gas to evaporate. read more Vince O. What is the minimum compression for my STIHL chainsaw? Each chainsaw has a different level of compression. But the saw just has a rubber piece on the top shroud with a slotted nut that just fastens it to a stud on the cylinder head, where the valve should be. Press question mark to learn the rest of the keyboard shortcuts. The compression limit should also be doubled if the engine capacity is 100 CC. This is bad practice, and can damage your chainsaw. The chainsaw has grooves all around the outer edge of the guide bar, and the chain has teeth that run within the bar rail to keep the chain in place and moving straight. Wipe off any flammable fluid from the metal surface of the engine with a clean rag. Mar 24, 2019. Unscrew the spark plug wrench using a spark plug from the engine. After that, using a ratchet, remove the spark plug from the engine. Usually, this happens when you use a chainsaw after a very long time or by wear and tear of the rope. "datePublished": "2017-08-17", If you refuel your chainsaw and it still won,t start, below are some of the possible causes and solutions that will get the chainsaw functioning again. 1. saw has new carb 2. flywheel has been removed and key inspected. Of all the Stihl saws, the MS250 is the toughest to start in relation to it's size.