QuestionI am working on a Craftsman mower with a 6.5 HP B&S engine that does not have a manual engine speed control. I had to clean the carb bowl and float to keep it from leaking gas and it is OK now. It runs OK but the idle is so low, it dies if I don't advance it at the carb. The tension spring is loose, but I think it is attached properly from the diagrams I have been able to find. The mower model # is 917.388550 and the B&S engine # is 123K02-0258-E1. Can you Help?
AnswerI assume you are talking about the engine RPM's are too low by saying the idle is too low.
TNL (Top No Load) Rpm's should be set at 3100 on this engine. If the spring is loose then it is either connected at the wrong points, or the tab has been bent, or it may be the wrong spring. I would assume that your have the correct spring though. The spring connection points will be determined whether your engine has as internal governor or a vain type governor and which control bracket the engine has.
The most common issue that causes this problem is the control bracket. The point where the spring connects sometimes gets pushed back towards the engine during use by running under a bush or something, and loosens the tension on the spring.
The spring should connect at the top big hole, (which is most common). You will notice that you can bend this bracket the spring connects too out to put more tension on the spring.
Be aware that it is very crucial that the correct RPM's are set and not to high. To high RPM's may result in internal engine damage.
Hope this leads you in the correct direction.
John
