WildnCrazyGuy
ArboristSite Operative
Trying to simplify things a bit for carb tuning. I went from zero knowledge just a few months ago, to way too much knowledge at this point after reading all the posts on here regarding this subject. I mean if you read some of these tuning threads, it's a bit overwhelming. So, with my limited knowledge of tuning my 2 stroke equipment, saws, blowers, trimmers, etc., I wanted to check to see if I understand the concepts correctly, or if I need to adjust what I think I know and learn more. So here goes.
1. Begin with fresh fuel mix, clean air filter, check fuel filter, clean or new spark plug, clean muffler and spark arrestor.
2. Start with the L and H screws out from seat at about 1.5 turns for most 2 stoke carb applications.
3. Begin with idle, L, and LH or T or whatever opens the butterfly and adjust until idle is steady and continues to idle when turned every which way but loose. (Up, down, right, left, etc.) Then adjust the LH or T or whatever to keep the chain or clutch from spinning and continue to allow for proper idle. Turn it all around again to make sure it doesn't die. The L and LH together will allow for proper throttle response when the trigger is depressed. If there is lag or hiccup, then adjust the L leaner, clockwise toward seat until idle and throttle response is acquired.
4. End with turning the H to proper MAX rpm. Turn clockwise (right) to go faster (lean), turn counterclockwise (left) to go slower (rich).
If tuning by ear, then err on the slow side with H. Listen for the device to start to scream, then back it off until starts to have hard time keeping up, then put it somewhere in the middle.
If using a tach, as long as the desired idle rpm and max rpm are reached and the throttle responds well, is the saw pretty much tuned at this point? Is it possible with a tach to reach this effect (running great with the proper idle, response, and max rpm) with a saw or really any 2 stroke and run it lean, burn the piston if you stay below the MAX rpm for the saw or device? The only other thing I know to do is pop the spark plug after running a bit and see if it is dark and wet (rich), white (lean), or light tan (just right).
The reason I go through all this, I have a new TT-20K tach and it seems that I'm still dark and wet (rich), on a little Poulan from my testing this weekend. I can consistently rev to 12-12.5K and it still looks rich to me. Poulan gave me a MAX of 12K for the 2150. I've seen 12.6K as well for that model so I'm thinking the Poulan tech wanted me below by a bit for my own good. Rich is better than lean obviously, but wondering if I was off on any of my tuning methods. Started with my little $20.00 Poulan in case I blew it up. Now I need to move on to my Stihl's, so I want to make sure I'm on track with this method.
Also, when I pulled the plug on the 2150 Poulan, it was wet and dark (rich), but maybe it should be that way given that I only idled and revved the saw for a few seconds at a time while getting it to MAX rpm. Would it probably go more tan like it's supposed to if I were to actually get to run it in wood during normal course? Or, maybe while I was getting the settings right, it was rich and the plug didn't get enough time to clean itself when I did get the rpm's right. Much thanks for useful input.
1. Begin with fresh fuel mix, clean air filter, check fuel filter, clean or new spark plug, clean muffler and spark arrestor.
2. Start with the L and H screws out from seat at about 1.5 turns for most 2 stoke carb applications.
3. Begin with idle, L, and LH or T or whatever opens the butterfly and adjust until idle is steady and continues to idle when turned every which way but loose. (Up, down, right, left, etc.) Then adjust the LH or T or whatever to keep the chain or clutch from spinning and continue to allow for proper idle. Turn it all around again to make sure it doesn't die. The L and LH together will allow for proper throttle response when the trigger is depressed. If there is lag or hiccup, then adjust the L leaner, clockwise toward seat until idle and throttle response is acquired.
4. End with turning the H to proper MAX rpm. Turn clockwise (right) to go faster (lean), turn counterclockwise (left) to go slower (rich).
If tuning by ear, then err on the slow side with H. Listen for the device to start to scream, then back it off until starts to have hard time keeping up, then put it somewhere in the middle.
If using a tach, as long as the desired idle rpm and max rpm are reached and the throttle responds well, is the saw pretty much tuned at this point? Is it possible with a tach to reach this effect (running great with the proper idle, response, and max rpm) with a saw or really any 2 stroke and run it lean, burn the piston if you stay below the MAX rpm for the saw or device? The only other thing I know to do is pop the spark plug after running a bit and see if it is dark and wet (rich), white (lean), or light tan (just right).
The reason I go through all this, I have a new TT-20K tach and it seems that I'm still dark and wet (rich), on a little Poulan from my testing this weekend. I can consistently rev to 12-12.5K and it still looks rich to me. Poulan gave me a MAX of 12K for the 2150. I've seen 12.6K as well for that model so I'm thinking the Poulan tech wanted me below by a bit for my own good. Rich is better than lean obviously, but wondering if I was off on any of my tuning methods. Started with my little $20.00 Poulan in case I blew it up. Now I need to move on to my Stihl's, so I want to make sure I'm on track with this method.
Also, when I pulled the plug on the 2150 Poulan, it was wet and dark (rich), but maybe it should be that way given that I only idled and revved the saw for a few seconds at a time while getting it to MAX rpm. Would it probably go more tan like it's supposed to if I were to actually get to run it in wood during normal course? Or, maybe while I was getting the settings right, it was rich and the plug didn't get enough time to clean itself when I did get the rpm's right. Much thanks for useful input.
