Lanco 0 #1 Posted December 4, 2010 When I first bought my 71 800 special about a month ago in ran. It sat until i got a snowplow for it. Now i cant get it to start back up. Fires here and there but wont keep firing. Backfires through the carb fairly often. Plug keeps fouling. New plug? Or does the carb need adjusted? Its an 8hp Briggs :) Share this post Link to post Share on other sites
JimD 3,345 #2 Posted December 4, 2010 Could be time to clean and adjust the carb, or maybe a rebuild kit is in order. I m not too familiar with briggs engines. but some here are, and will offer good advice. :thumbs: Share this post Link to post Share on other sites
Coadster32 793 #3 Posted December 5, 2010 Carb is where I would start. Especially if you didn't run it dry before you let it sit. Share this post Link to post Share on other sites
bell 11 #4 Posted December 5, 2010 "plug keeps fouling" I'd start with a new plug and try to start it without using the choke, or only using half choke if it doesn't start. Share this post Link to post Share on other sites
Redbirdman 7 #5 Posted December 5, 2010 Fires here and there but wont keep firing. Backfires through the carb fairly often. If it's a Briggs I would think two things first...... A stuck (or bad) intake valve or a bad keyway in the flywheel. (or crap in the head holding the intake valve open just a CH) I would first consider the intake valve.......Has the machine not been running regular or too often? If so, the intake valve may be sticking open just a hair allowing gas to backfire out the carb. A really good spraying with cheapo "Tune up in a can" stuff from NAPA or Walmart down the plug hole sometimes does the trick. I used to swear by "SEA FOAM" from NAPA in the tank and a good spray in the cylinder down the plug hole to get things unstuck. A serious problem that is easy to fix is a bad flywheel key that has just a slight offset caused by a bad backfire or sudden stop of the engine. But you have to pull the flywheel to find the key. Not easy! A good way to check is ( of course ) a cylinder compression check. Poor compression could indicate an open (or stuck) intake valve. Backfiring through the carb is not always an indication of carb problems because the engine needs something to actually kick pressure backwards, and the carb only feeds fuel inwards..........but this is giving me a headache... Someone else, please help :ychain: Share this post Link to post Share on other sites
horsefeathers 15 #6 Posted December 5, 2010 I think Redbirdman is on the right flight plan here! Valve timing! You can try this Red Neck Tech trick! If the valves are stuck pull the spark plug. pour a small amount carb cleaner or sea foam in cylinder let it sit! feed a peice of rope in the plug hole pack it in and turn the engine by hand. That will hopefully losen a stuck valve without pulling the head. Flywheel key can be a problem also on briggs. Tapered fit... replace key and use valve laping compound to the crankshaft. That will keep from shearing key on engine kick back. You may try replacing carb base gasket! Vacume leak? But engine kick back sounds like valve timing to me. Share this post Link to post Share on other sites
bitten 134 #7 Posted December 5, 2010 Horsefeathers what does the rope in the cylinder do? Share this post Link to post Share on other sites
dave24 18 #8 Posted December 6, 2010 it sounds like maybe some bad points, but could be a stuck intake valve, check wiring, possibly some mice also Share this post Link to post Share on other sites
WH nut 553 #9 Posted December 6, 2010 Pull the plug and leave the wire on the plug and check your spark by grounding the plug and crank it over. Should be a nice blue snap. While cranking you will bow and excess fuel out. If you have a good spark, reinstall the plug and try to start with out the choke Share this post Link to post Share on other sites
Redbirdman 7 #10 Posted December 6, 2010 Should be a nice blue snap. While cranking you will bow and excess fuel out. But don't do this in a closed old wooden shed with lots of spilled gasoline all around. Don't ask me how I know this tidbit of information........... :ychain: Share this post Link to post Share on other sites