Monday, September 15, 2014

Big Jugs

Getting down to business right here - jugs, pistons and rings. The second compression ring is the gap-less type, top compression ring is conventional one piece. I checked the end gaps and most everything was good as is. Two of the rings took a quick swipe with a file to get the gaps within spec. I also remembered to check which way the pistons should be oriented prior to installing them. Valve pockets face each other for intake valve clearance. There's a little excessive clearance between the piston pin and the connecting rod but not much I can do about that other than buying a new set of pistons. Can't see that happening right now.

Here are the pistons in the cylinders ready to be bolted down. The nuts holding the cylinders down are supposed to be taller than normal, like you would use on a U-bolt for a leaf spring. I went through the boxes and bags of parts and didn't see anything that looked like that - didn't see a set of eight plain Jane ones either. I'll run uptown this morning and see if the auto parts or hardware store have any. 

If you look in the lower right corner of the photo you can see the new breather tube. The stock one was looking a little shabby so I sprung for a chrome one. Nice and shiny but didn't fit initially. I had to file a bit to get it to thread up in the cover and the top bend was not bent enough. I bent that a bit more and added a second bend below it to match the case profile. Looks pretty snazzy now. On the left side of the photo is the new sprocket. I need to make a tool for holding the sprocket while tightening up the nut on the countershaft. Surly has an old piece of chain I can slice up to make a tool that wraps around the sprocket. I'll talk to him about that or I could make a spanner with a couple of pins in it to match up with the holes in the sprocket. 

While I had the carbs out I checked things out a little closer. The stock one that came with the bike initially appears to be a 38mm - the bore is tapered inside. The other factory carb is a 37mm, so they are both smaller than the 1-7/8" on the S&S but the S&S does have the restrictor. I was fiddling with the S&S and could see that the accelerator pump rod wasn't doing anything so I took things apart to see what was going on. Just stuck from some gasoline that had turned to varnish. As long as I was piddling with things, I cleaned the rest of it up and checked out the main jet. It's a 64. Don't know if that's good or not, not having any experience with these things but I've got a number to start with.

I also took a look at the head gaskets. The previous owner had some thinner ones he saved because they'll give a little more compression than the ones in the gasket set -.017" versus .0325". I don't know how much difference there would be in the compression ratio between the thick and the thin but I'm thinking for ease of starting, thicker is better.

So no painting yesterday, in spite of the good weather for it. I really wanted to get something done on the bike. I've been thinking, I might not even try to light this thing off this year. By the time I get it all together it's going to be pretty late in the season. Not much sense in pouring gas in it and adding acid to the new battery just to let it sit for six months.Of course I could just hook some jumper cables up to something else and it's not that tough to drain the gas tank and the carb. I would like to hear it run. If nothing else just to know it will run so I can have it ready for next Spring. 

Depending on the weather, painting schedule and missing hardware, I'm going to try and have the top end buttoned up this week. 


Surly said...

I sent you an email. I have a spare set of pistons. I'll check and see if they include wrist pins.

Shop Teacher Bob said...

Roger that.