Stripped and Leaky

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

Nutting (and Bolting)

This is good, I should do this to all my bikes.

I Jinxed Myself

I've been telling people about how I'm so close to getting my moped running and I'm pretty sure I jinxed myself. I finally had some time to spend cursing at the Honda and of course I found as many problems as I fixed. 

First fix was pretty easy, the pinhole in the top of the gas tank. I had intitially patched it with a piece of bubblegum because according to a the friendly youtubing Canadian, AvE, gum is made from a petroleum resistant food grade plastic so it would be perfect for the job. Turns out, it doesn't work, it just kind of melted. Maybe Canadian gum would work better. 

No matter though. The quarter I used to seal the leaky oil sight seems to be holding up great, so I just JB welded a dime over the pinhole on the top of the tank.

The main project was making the engine stay together nice and tight. I got new engine studs and helicoils in the mail the other day so I was ready to fix the stripped out threads in the crank case. 

When I opened the case, a bunch of water came out. No good. Where did this crap come from? I contemplated this while I installed helicoils in two out of the four holes. Each one took a couple tries and the top right (the bike's right) has two helicoils stuffed in there. The bottom left one had to be drilled a bit more and neither were drilled very straight (Not my fault! It was the other guy that worked on it before me)

So now I have good threads in a case that had a bunch of water in it. I'm trying to soak up the puddle with a rag and then spray some compressed air and wd40 in there and hope for the best. I tightened the oil pump, maybe that's where the water came in? Maybe it was the loose studs?

I'm glad that hole in the tank is patched, but looking at the fuel lines, I'm wondering if the two parts of the tank are still sealed off from each other. There looks like there's a whole lot of oil in the gas line. 

The bike is still in parts in the kitchen, so I guess my next step is to try to dry and reassemble the engine and see if it'll fire. Then maybe try to figure out it the tank is keeping the oil and gas separate. Maybe I will be buying a new tank and premixing. 

Or maybe I'll just throw the godforsaken bike into the river because it seems like my bike hates me. 

Hella Coils

I hope I'm better at installing these things than the previous owner. Hopefully they'll hold. I'm not super optimistic. This bike doesn't seem to want to run and the other person that worked on this before me is just as bad at working on engines as me, if not worse. I really hope this works. 

I'm just waiting on the engine studs. Partmonster or whatever website I ordered them from said they should be here Wednesday. I'll let you know how it goes. 

One Step Forward Two Steps Back

I brought the 'ped inside today to see if I could figure out how I could keep this engine together tight enough to hold compression and run (see previous post for details of stripped engine studs). While dragging it's lifeless body in from the street, I noticed not only was the carb still leaking (I have to remember to get some gaskets to hopefully solve that problem) but there was also a pinhole leak in the tank right by the gas cap.

Welding the hole shut would probably be the ideal solution... even JB welding it would be pretty ok (I JB welded a quarter over the leaky oil sight window previously) but, whatever. I just chewed up some gum and smushed it over the leak. Oh god how this bike must hate me.

I can tell it hates me. It should, I've done little other than fool with it and fix it poorly, and I've taken way too long to do what few shoddy repairs to it that I've done so far. This bike has a history though. I've learned a bit about it today. The engine case has been heli coiled. Not only did a previous (more than one, I assume, I don't know how many) owner cook the wiring harness by welding a coil mount under the seat, the case was drilled and heli coiled.

This is the root of my problems. Fucking Heli coils. I bought a tap/die set from Home Despot in hopes of cleaning up the threads and having everything work out. Did it work? Hell no!

Instead of chasing some M6 x 1mm threads in the case, I ended up removing the heli coil. Also, it's been drilled out so much that I can't tap it to a 7mm thread and just use oversize engine studs.

I guess I'm going to try to heli coil it once more. I have to look up the whole helicoil thing first.

Whenever I think I've fixed one thing on this hunk of junk, I find two more things wrong with it.