My little Honda Express NC50 still sits in my kitchen with its engine in pieces. I'm sick with some kind of cold/flu/phelmpocalipse. The helicoils didn't hold in the bottom left (bikes left) hole and stripped out my brand new engine stud.
So, I dabbed some good ole JB weld on the stripped out helicoil hole and I'm going to try to tap and coil it again. I'm hoping that will be enough for the coil to hold.
Also, I'm going to switch to the older style engine studs. The newer ones are just bolts that go through the head and cylinder and screw into the case. Every time you pull the head you have to undo and then reinstall these screws into the case. Everytime you do this is an opportunity to chew up the threads in the case. When reinstalling, the head, 2 gaskets and cylinder are in one hand while the other hand is juggling and installing these 4 long screws to hold the whole thing together. This seems like a great way to crossthread those screws and have to helicoil.
It seems like most other engines have studs that are like a threaded bar that screws into the case and then the cylinder, gaskets and head slide onto these studs and then nuts and washers tighten the whole thing together. This means the stud/engine case connection is messed with less and the helicoils probably stay in more securely.
The 1977 Honda nc50 parts sheets have regular style threaded bar type studs while later models, including my 1980, have the bolts that seem to want you to ruin the threads in your case. I'm wondering why this changed. The older ones had nuts and washers at the end of the threaded bar so that's three parts for each stud and there are four so that makes 12 parts. The newer style ones just have the four bolts. Maybe it was a cost saving, simplifying thing.
I'm slightly concerned the stud change might be a servicing thing. There's a bar between the footpegs that's right there by the head and I hope it wouldn't get in the way when putting the cylinder and head on the threaded bar style studs. I wonder if the old style setup required removing the engine from the frame to mess with the head etc. I guess I'll find out. If I have to pull the engine to make it happen, then that's just what I'm going to do.
Also, the tank doesn't seem to be keeping gas and oil separate. The gas turned blue from the synthetic 2 stroke oil, and the oil, smells like gas and seems very thin. I think my short term solution will be to just plug/loop the oil injection and run it premix. A long term fix might be a tank sealer kit, but I'm not sure how big the leak is. Maybe I'll be getting a new tank. I've always liked the idea of getting rid of the rack and tank setup on the back and putting something on the backbone or top tube or whatever you call it. I'm pretty sure it'll run on the mix I have in the tank right now, even though the mix is really heavy on the oil. I'm going to solve the engine stud problem first and worry about the tank later.
Shopping list:
Older style engine studs/nuts/washers
Blue locktite for the studs
Exhaust crush gasket
Maybe a torque wrench
Perhaps some feeler guages
So, I dabbed some good ole JB weld on the stripped out helicoil hole and I'm going to try to tap and coil it again. I'm hoping that will be enough for the coil to hold.
Also, I'm going to switch to the older style engine studs. The newer ones are just bolts that go through the head and cylinder and screw into the case. Every time you pull the head you have to undo and then reinstall these screws into the case. Everytime you do this is an opportunity to chew up the threads in the case. When reinstalling, the head, 2 gaskets and cylinder are in one hand while the other hand is juggling and installing these 4 long screws to hold the whole thing together. This seems like a great way to crossthread those screws and have to helicoil.
It seems like most other engines have studs that are like a threaded bar that screws into the case and then the cylinder, gaskets and head slide onto these studs and then nuts and washers tighten the whole thing together. This means the stud/engine case connection is messed with less and the helicoils probably stay in more securely.
The 1977 Honda nc50 parts sheets have regular style threaded bar type studs while later models, including my 1980, have the bolts that seem to want you to ruin the threads in your case. I'm wondering why this changed. The older ones had nuts and washers at the end of the threaded bar so that's three parts for each stud and there are four so that makes 12 parts. The newer style ones just have the four bolts. Maybe it was a cost saving, simplifying thing.
I'm slightly concerned the stud change might be a servicing thing. There's a bar between the footpegs that's right there by the head and I hope it wouldn't get in the way when putting the cylinder and head on the threaded bar style studs. I wonder if the old style setup required removing the engine from the frame to mess with the head etc. I guess I'll find out. If I have to pull the engine to make it happen, then that's just what I'm going to do.
Also, the tank doesn't seem to be keeping gas and oil separate. The gas turned blue from the synthetic 2 stroke oil, and the oil, smells like gas and seems very thin. I think my short term solution will be to just plug/loop the oil injection and run it premix. A long term fix might be a tank sealer kit, but I'm not sure how big the leak is. Maybe I'll be getting a new tank. I've always liked the idea of getting rid of the rack and tank setup on the back and putting something on the backbone or top tube or whatever you call it. I'm pretty sure it'll run on the mix I have in the tank right now, even though the mix is really heavy on the oil. I'm going to solve the engine stud problem first and worry about the tank later.
Shopping list:
Older style engine studs/nuts/washers
Blue locktite for the studs
Exhaust crush gasket
Maybe a torque wrench
Perhaps some feeler guages
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