Home › Forum › Ask A Member › Lightwin Problems › Re: Lightwin Problems
If the impeller was dry and cracked then the water tube grommet on the pump housing probably was to and needs changing. The small copper water tubes on these motors bend easily and must slide into the grommet smoothly. A light sanding on the end of the tube to remove any crud and a light coating of silicone grease or any grease will help to make sure it reassembles properly. If the tube wasn’t fully seated, it may have been pushed up and rubbed on the drive shaft wearing a hole in the side of the tube. Something else to check.
When building a three horse motor, I find it easiest to install the gearcase first. This way the alignment of the water tube can be checked from the top of the midsection with a flashlight. If everything is good, then the powerhead gets screwed on.
Also make sure the water tube is clear! I have a ’57 Lightwin which had cooling issues. After several teardowns I traced the problem to a small stone which had made its way thru the pump and lodged in the bend at the top of the tube. It would let air pass when blowing it out but not enough water to cool the motor.