hey guys, I just bought a 79 cb750 off of my friends uncle for 500$. I may be able to post pictures later on to show the amazing condition it was in when I bought it. The guy had it worked on probably a year and a half to two years ago and his mechanic rebuilt the carbs (lucky me), got new spark plugs, and put new tires on it (lucky me again). He had it running but out of sync and it was backfiring really bad from what I've been told. I tore into it and cleaned the carbs back out, wire brushed the spark plugs and started electrolysis on the tank because it was super rusty.... I now have the bike running after two days of ownership
but....... I had to bench sync the carbs to get it to run and not backfire, and I've now run into the problem of it either starving for fuel or a bad vacuum leak.... I cleaned the carbs out completely, I haven't gotten them soaked yet because I don't want to do that myself, and I semi checked for vacuum leaks using zep around the intake boots... to no avail...
It'll run, but it idles down super slowly and it will stall out under 1800-1500 rpms...... I'm stuck. Before I get pummeled with the "you're a moron" comments, keep in mind I'm only 18 and have already rebuilt a 74 cb360 and an 85 magna... I also don't have the money or time to buy the carb soak stuff and take the carbs all the way apart to soak them... Someone please help me diagnose whether it is an air leak or lack of fuel... I've had too many varying comments from people I know on the matter to be sure... My need to know comes from the fact intake boots are around 60-90 bucks from what I've researched, and soaking the carbs with someone I know would probably be around 40-50$ so I don't exactly have the money to do both and then have the possibility of neither of those fixing my problem... HELP please haha
but....... I had to bench sync the carbs to get it to run and not backfire, and I've now run into the problem of it either starving for fuel or a bad vacuum leak.... I cleaned the carbs out completely, I haven't gotten them soaked yet because I don't want to do that myself, and I semi checked for vacuum leaks using zep around the intake boots... to no avail...
It'll run, but it idles down super slowly and it will stall out under 1800-1500 rpms...... I'm stuck. Before I get pummeled with the "you're a moron" comments, keep in mind I'm only 18 and have already rebuilt a 74 cb360 and an 85 magna... I also don't have the money or time to buy the carb soak stuff and take the carbs all the way apart to soak them... Someone please help me diagnose whether it is an air leak or lack of fuel... I've had too many varying comments from people I know on the matter to be sure... My need to know comes from the fact intake boots are around 60-90 bucks from what I've researched, and soaking the carbs with someone I know would probably be around 40-50$ so I don't exactly have the money to do both and then have the possibility of neither of those fixing my problem... HELP please haha