Hello<br />Just got finished doing the annual getting winter equiptment ready for the season and am having trouble with the snow blower. it is a mtd make with a 8 horse tecumseh motor. approximatly purchased new in 1992 or 93. problem i am having is it just does not run right, real erratic. revving up and down. i am thinking carb needs adjusting? any hints on the best way to do this? what screw does what? do you turn them all the way in and then so many turns out? there are two on the side of carb, on up and one lower. then there are two on the bottom of bowl. one i figure is to drain the bowl. thanks for any help. On a better note the ice auger is running great!!
<br /><br />Fshkpr,<br /><br />Glad you got it running good, but it sounds like the carb needs cleaning. The erratic idle is a classic symptom of a dirty carb, and that gummy stuff you found was not just on the needle, but everywhere. Typically the motor will start to run crummy again after an hour or so use because the rest of the crud works its way around inside the carb. But before you take it apart, try cleaning it on the motor with a spray carb/parts cleaner like this: <br /><br />1) Run the carb dry so the engine stalls. <br />2) Screw in both needle screws (side and bottom) counting the turns until they bottom (gently) and record this so you can set them back when you reinstall them. <br />3) Unscrew both needles.<br />4) Spray in the cleaner using the long nozzle in both needle holes. Gently press in the straw so that the spray goes through the internal passages. <br />5) Replace both needles, and set to the setting recorded in step 2.<br />6) Remove gas line from carb and fill carb with cleaner through the gas line connection. It only takes an ounce or two.<br />7) Reconnect gas line.<br />8) Let set a few minutes.<br />9) Start motor and run about 5 seconds then shut off and let set a few more minutes. It may be really smokey.<br />10) Start motor and run until exhaust is no longer smokey.<br />11) Make fine adjustments to idle and thrust needles.<br /><br />If that doesn't do it, the carb is easy to rebuild with a kit that has new needles, bowl gasket, and aluminum knock outs. If you do the rebuild, don't forget to remove and replace the knockouts otherwise you can't clean the passages well. This is a common mistake when doing a rebuild on these carbs. <br /><br />To remove the knockouts, drive something sharp like an Awl into the center of it at a low angle then pry out. Be careful not to hit the interior of the carb, but it's just passages if you do, hard to mess up unless you go bonkers on it. Then use the gum cutter or other carb cleaner to clean it out, soak it, etc. Blow clean & dry and drive in the new knockouts with a wood dowel. Just enough so they have a slight dimple and don't fall out.<br /><br />Sometimes it's harder to get the carb off than to rebuild it! <br /><br />Good luck,<br /><br />Mark.