Grouchie's 1977 build thread

grouchie77

That was broken when I got here boss
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At last I think it's a good time to start reassembling things and make forward progress.

This is going to be a long read, be forewarned.

This bike was originally my Dad's. He had bought it brand new in '76. Fast forward a few years and my brother was born. I showed up a few years later. With two small boys and a mortgage, and as the sole breadwinner, money was a little tight for Dad.

He had come to an agreement with his dad that my Dad would sell him the Yamaha, on the condition that his dad was not to sell it, and that my Dad would work overtime and pick up Saturday shifts at the factory until such time as he could afford to buy the bike back.

So Dad worked long days, long weeks, long years, until such time as he had squirreled away enough spare pocket change that he could buy his Yamaha back.

In the one good deed that his dad did, he told my Dad to keep his money to support his family, and gave my Dad his bike back.

I remember Dad riding that thing on warm summer days home from work, down the alley to make sure me and my brother weren't being little hellions and breaking into parked cars.

Eventually Dad tucked it away in the garage, and it sat for maybe 15-20 years.

After I turned 18 and my Dad booted my ass from the house and he had spending money again and paid off some bills and debt, he decided to get the ole Yammie back on the road. When my brother and I were kids, Mom and Dad had a concrete slab poured in the backyard, and a basketball pole and hoop installed. Not needing the mini basketball court anymore, I remember Dad wheeling the Yamaha out of the garage, laying a tarp down on the court to not stain it, and working on the bike again, as he had done so often in his youth.

He got it running again, and it ran like a champ.

Once again, I remember Dad riding that bike to and from the same factory he had worked at for 35 years.

For years I offered to buy it from him. And for years he said no. Didn't say why, didn't even name a price. Just flat out refused.

A few years after I had moved to California from Illinois, he had finally had enough "fun" working at that factory, and being married, and packed up his truck and a trailer for his Yamaha, and moved to Arizona to go to where he called home.

Being a dry as shit climate, Dad simply parked the Yamaha outside. And sadly, that's where she sat, neglected once again.

Every Thanksgiving and every Christmas I would drive the 400 miles to see Dad, since I was pretty much the only family around. My brother was stationed overseas and while they couldn't be married anymore, my Mom and Dad were still friends. He continued to pay the mortgage and Mom's bills and shit like that, but as better friends than they had been in 20 years.

One day a few weeks before Thanksgiving one year, Dad calls up and asks if I had planned on coming to visit again. I said of course. He told me that if I wanted the Yamaha I could have it, otherwise he would try to donate it somehow, or take it to the scrapyard.

So of course I immediately jumped at the opportunity to have this bike that I had been trying to buy for years. I ordered a hitch for my MINI Cooper, worked late into the night to install it, and the next morning I had a trailer light harness installed.

Went and visited Dad, and as he helped me load the bike into the trailer, he handed me his old manuals and the title, wished me a safe journey and good luck with the bike. Gave me a piece of paper he'd typed out with some good parts vendors on it and said he'd gotten parts from a few of them.

Now, here is where I will throw out the fact that I had never ridden a bike before. I knew the theory behind it, clutch in, shift, clutch out. Repeat as needed. My first truck was a stick.

So back in California, I immediately start taking this bike apart to rebuild the engine.

Meanwhile, I take the title to the DMV and there was my first experience with the California DMV.

"Yeah hi I need to get this title in my name."
"Do you have the bike here?"
"No, it's in pieces at home, I'm rebuilding the motor."
"Then you don't have a bike, you have pieces of a bike. I can't transfer the title to you until you have a complete bike."

Ugh. Great so now I gotta throw the motor back in the bike, and have my buddy ride it to the DMV so they can fucking look at a complete bike. (Yeah I didn't have a Class M yet).

Get the title and a plate, and my buddy teaches me how to ride the thing.

From there I rode the thing for years, always tinkering with it, changing this doodad here, machining some part for it there.

Fast forward 10 years. I'm married, have a great job. Me and the Missus decide to take a vacation for our anniversary to Arizona to see Dad. On the plane ride there, I read a book about disassembling the motor to a level I had never done before, and I get the idea that that's what I'll do after we get back from vacation.

After vacation, motor comes back out, because I am bound and determined to get a good look inside this thing, and also to make it kickstart only.

Three long winter months later, having not touched the bike since my apartment garage was unheated, my wife and I decide that "this place has really gone downhill in the past 8 years" and end up buying our first house.

One can only imagine how excited I was at the prospect of getting a 2-car garage all to myself. From there I stripped the bike completely apart down to the frame, and now the engine is in many pieces.

That's the history of the ole Yamaha.

What I want to do is turn this into a chopper. Not a chopper.... a hotrod on 2 wheels.

In the time I have gotten this bike I have learned how to TIG weld (when I say learn I mean I took a night class at my local college and zapped a few bits of 1/8 strip steel together) but more importantly, my CNC milling skills and abilities have improved a thousand fold. I have a key to the door at work, and the owners told me that even though they are the owners, it's "everyone's shop". So if I want to stay late off the clock to work on personal shit, they could care less.

So my plan is to hardtail it, make it kick only, and add a springer front end. My Dad is entering his autumn years, and I would really like to make this thing a runner in his lifetime so he can "take it around the block" since he had told me he always wanted to make it a chopper himself but it wasn't a priority.

But first I need to get the motor back together. And that starts with me running to the store to grab some crankcase sealant.

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This isn't the first time I've rebuilt this engine, and I did think of that. Figure with the 180° firing order, trying to throw both slugs in at the same time would be difficult. I forget how I did it last time, I think I just went real slow and took my time to avoid cracking a ring.
 
Also, thanks for posting that topend link. A good read.
Thanks. I wrote that for a forum member who had zero experience putting engines together. It gave him the confidence to rebuild his top end and wound up with a sweet running bike.... Black Betty.

RobinC passed away shortly after and @MaxPete now has Black Betty. Still a good runner as far as I know. Rip Robin.
 
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I've always been better than most of my friends and family with mechanicals and such, but there were some things in that article that I didn't do the last time I had top end apart like check camshaft sideplay. I've found that watching episodes of Hot Rod and what they do to muscle car engines translates pretty well over to the parallel-twin world, as far as checking ring gap and lapping valves and such.

Plus reading that gave me something do to on my lunch break. :thumbsup:
 
Thanks. I wrote that for a forum member who had zero experience putting engines together. It gave him the confidence to rebuild his top end and wound up with a sweet running bike.... Black Betty.

RobinC passed away shortly after and @MaxPete now has Black Betty. Still a good runner as far as I know. Rip Robin.
Yup - Betty’s had her challenges lately (broken and missing engine mount bolts and a busted clutch cable) but she does run extremely well!
 
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Took the pistons off the rods, put them in the oiled cylinders. Used a variation of the popsicle stick method.... I have no popsicle sticks so I found a small branch in the firewood pile and put my pocketknife to work.

Spun the engine sideways on the stand so the cylinder wouldn't use the old gravity-assist and make life difficult.

I must interject that I fucking love this engine bracket adapter thingy I got from ChopSource.

https://www.chopsource.com/deluxe-yamaha-xs650-engine-stand-brackets.html

Free advertising!

Put the wrist pins in and the circlips and pushed the cylinders home.

Wire-wheeled and lapped the valves and reassembled the head which took forever with my c-clamp and keeper removal tool.

Didn't help that I spotted a spare washer when I was halfway thru and had to undo the right intake to throw the washer under the springs and reassemble that quadrant.

Wire wheeled my sparkplugs and gapped them to .024" go, .025" no-go.

Threw the plugs in the head and did a rudimentary leak test.

Sat on my stool for 5 minutes and took a breather, then cleaned the front camchain guide hardware in the parts tank to get those shiny.

Used the oil in the combustion chamber to oil the head gasket, placed the head on and covered it with an Amazon box (there's a reason I horde boxes) to keep debris out.

Next up- scrubbing the rocker box. But since we have a long weekend, the wife will have me catch up on chores. And she's not wrong, the gutters haven't been cleaned in who knows how long. There's small trees growing in them.
 
For testing the valves for leaks, after filling the combustion chambers with solvent, I blow compressed air in the intake and exhaust ports ......

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Leaks will show as streams of bubbles emanating from between the valve and seat .......

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However, you may need to play around with the positioning of the blow gun. Get it too close to the valve and you'll actually blow it open, lol. Still, I feel this is one of the best ways to test valves for leaks because it shows them all. even the little ones. And there's no having to wait hours and watch for leaks either, this method is like "right now" and instantaneous.
 
Seems I'm missing a sleeve in my rocker box. Hopefully it's in my pile-o-parts. If not I'll pop out one of the 3 left and make a replacement sometime at work.
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(p/n 256-11199-00-00)

Also, this one adjuster seems to have some wear. The other 3 also have wear but this one has the most. Opinions? I neglected to look at the valve stem tips but I will have to do that.
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Had a few free moments this morning after yard work so I cleaned off the workbench and started disassembling the rocker box so I can clean it in the parts tank.

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Used some leftover gum containers (which I have TON of since I go thru gum like water after I quit smoking 6 years ago) to segregate the different quadrants' parts and pieces.

Will have to make a slide hammer with an M6 thread at work Monday but I was able to get the plugs off so that was nice.
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Finished my slide hammer yesterday after work, so I could get the rocker shafts out. Worked just like I dreamed.

Got the box completely disassembled, scrubbed the casting. Inspected the cam bearings, they look and feel almost new. Got the cam and new chain installed, but I either lost or never had a rivet tool, so I'll have to stop and buy one or look for one. Will probably scrub the casting some more since the cam link isn't riveted yet.

On a side note, I've noticed that when the keyway on the crankshaft is pointed directly down, the pistons are at TDC.

Can anyone off the top of their head confirm this?
 
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