rick martin 65 #1 Posted June 5, 2019 so i just finished a pretty major tune up, rebuilt carb,new fuel pump,new fuel lines,new filter,new plug. runs great for about 5 minutes than it seems like it gets real hot and wont run. if i let it cool down it will fire right back up and run great for another 3 to 5 minutes than runs like crap again. not sure what to check out next, coil,condenser,ignition? any help or direction would be awsome... thanks Share this post Link to post Share on other sites
SylvanLakeWH 28,443 #2 Posted June 5, 2019 Is the gas tank venting properly? Share this post Link to post Share on other sites
rick martin 65 #3 Posted June 5, 2019 seems to be working correctly. not sure how i would check that other than blowing through it. Share this post Link to post Share on other sites
Marv 982 #4 Posted June 5, 2019 23 minutes ago, rick martin said: seems to be working correctly. not sure how i would check that other than blowing through it. I have seen cases where the vent in the cap has rubbed against the hood enough that it restricted the venting to the tank. I drilled a "small" vent hole on the side of the vent dome. Solved the problem. Marv 1 Share this post Link to post Share on other sites
lynnmor 7,824 #5 Posted June 5, 2019 If the fuel mixture goes lean, the engine will run hotter. If you have a high speed mixture screw, adjust it richer. If you have a carb with no adjustment, perhaps you need to clean some more. If it ain't the carb, then check for air leaks at the intake. Share this post Link to post Share on other sites
rick martin 65 #6 Posted June 6, 2019 thanks guys, will check it out tomorrow. i do have an adjustable carb that ive tried to adjust. maybe ill try to adjust it again. Share this post Link to post Share on other sites
Guest 88vic #7 Posted June 6, 2019 Possible valve adjustment or some issue with the valves. If the valves dont open properly it can also build up heat and cause running problems. Youll know a lean running condition especially in the dark you can see the muffler glowing red, indicating an issue. I would hold off on running it anymore until you find the culprit. Share this post Link to post Share on other sites
lynnmor 7,824 #8 Posted June 6, 2019 27 minutes ago, WHEELHORSEFAN*16 said: Possible valve adjustment or some issue with the valves. If the valves dont open properly it can also build up heat and cause running problems. Youll know a lean running condition especially in the dark you can see the muffler glowing red, indicating an issue. I would hold off on running it anymore until you find the culprit. That too, as an engine warms up the valve clearance gets smaller, so that needs to be checked. Share this post Link to post Share on other sites
Guest 88vic #9 Posted June 6, 2019 Exhaust valve clearance is always more than intake valve clearance since it gets hotter of course. Share this post Link to post Share on other sites
Bonacker 49 #10 Posted June 6, 2019 the coil could be going bad its getting hot 5 Share this post Link to post Share on other sites
Mike'sHorseBarn 3,248 #11 Posted June 6, 2019 Before you go messing with the engine a whole lot, try a new coil. Sounds like a classic case of a bad coil. Share this post Link to post Share on other sites
rick martin 65 #12 Posted June 10, 2019 Got it all figured out, new set of points and condenser and it's running like a top again Share this post Link to post Share on other sites
