Trash

[sgallaty]

I don't think the oil was ever changed. Yes, I bought the bike on a gamble thinking that the internals of the engine had a good chance of being solid.

The key is going to be the cylinders. I'm about to pull the engine and find out.

EDIT:

Also, I can't find my impact screwdriver. I guess it was in the junk I left behind when I moved.

The hondas I used to work on had those shallow cut japanese philips head screws holding everything together. You get really good at taking out philips head screws - so the few philips heads I've run into so far have not stood a chance against me.

Compared to a CB750 whose side covers are recessed philips heads (you can't get a normal impact hammer bit on them), this bike has been cake. I did have one apparently stripped side cover bolt, but it looks like someone just tried to drive a 20mm bolt into an 8mm deep hole.

I did have 4-5 philips heads inside the case (on the stator for instance) and two on the carbs that I had to employ dirty tactics to remove. I hit them up with pb blaster, let them soak a bit and then put a philips head screwdriver in the screw and hammered on it a little (black magic for loosening up philips heads) then clamped a vice grips on the head very hard, and turned them. You pretty much only get one shot at it, because if the grips slip you'll end up tearing the head of the screw up and they may not grip again.

They all came out, some with a little more reluctance than the others. The screws in my alternator housing were solid blobs of rust.

 

[sgallaty]

removing the engine from the frame presently, taking a break for some java bean action.

took off the valve inspection covers and everything looks good in the top end. Looking forward to pulling off the heads and valve covers and seeing what I've got.

One small bummer, turns out the advance plate, advance rod, and contact plate is missing so I'll be looking for that.

 

[DogBunny]

Bummer about the points and advance rod and weights missing.
I'm not sure if I'm at fault, but I feel guilty about it anyway. There is a good chance that I pulled it. If I did, I was probably in a frenzy, and I swear that I have no specific memory of it. That stuff is very dear to me, I need it when I resurrect 1980 and later engines. It makes sense that I would pull those things off of a seized engine, especially one with only 7,600 K on the clock -- they were probably in really good shape. If I did it.

At least you have the advance rod bushings and the labyrinth bushings.

There's a good chance I needed a good engine sprocket too, and that I swapped it for ol' nubbins.

Whenever I look at an engine, I always pull the points and advance covers to see what's missing, and I always look for the alternator rotor and stator. I have learned this the hard way.

 

[sgallaty]

Well, by any stretch of the imagination I am still way ahead of the $200 bucks I put into this. We'll see how far ahead when I pull the heads.

The engine is out of the frame and awaiting my attention. I'm about to go out there and pull the heads right now.

EDIT:

Pulled off the so-called tappet cover. This made slightly more interesting due to the 4 rubber 'washers' that were on the outside valve cover nuts. They were completely smashed and deformed. May have been heat degradation.

Did not pull the head off yet. Getting dark, and I decided to call it after ~12 hrs on and off today.

What I found was not encouraging. The right side exhaust valve was stuck open but a gentle sharp tap on the stem with a hammer made it pop closed. I 'rung' the valves with a hammer just to see what they sound like and the left side exhaust doesn't 'sound' right. If you tap a valve with a hammer very gently you should hear the spring ring as the valve pops open just a bit, if everything's working right. If it sounds solid or dull, then the valve is hanging in the guide.

The left exhaust valve has an issue - haven't identified it yet.

There is discoloration and scoring on the two inner tappets and mild discoloration on the cams. I don't know if I feel that there is 'too much' discoloration, but it's there.

If I were to guess, I'd say that the bike was run without enough oil in it and the top end got oil starved and overheated. Not sure if this is what caused the bike to seize up, but we're about to find out what the pistons look like. At this point, I expect anything.

That said, the lower end really does look good and if I were to have to choose the lesser of two evils, I'll happily have the whole top end trashed before the bottom. If the pistons are shot and the cylinders aren't too fucked up, I'll rebuild from there.

I find out that tomorrow =)

 

[sgallaty]

Just got the heads off. The left cylinder was encrusted with something I can't exactly identify. I thought it might be rust at first, and there does seem to be some rust in the cylinder however... this stuff flaked off the cylinder wall into pieces and seems carbonaceous.

The right side cylinder has a little scoring, and a ring from where the piston was stuck.

The pistons are totally clogged with what appears to be carbon, but some of it is gummy. Burnt oil maybe?

The left side cylinder head has rust, and the left side exhaust valve is sticking.

I'm going to research the steps suggested for rejuvenating this head. At the minimum I am going to need a few tappets and valve guides. At the extreme I'll need new sleeves in the cylinders, new pistons and major head work.


I'm about at my budget this month, so the tools I need to continue will have to wait until next month.

 

[sgallaty]

7/14

Heads are off the engine, cylinders soaking in a derusting solution.

The parts I was waiting for arrived. Honda rebel shocks, a set of carbs and a rear fender.

It's pretty weird but the fender matches my tank.

Here's the workroom in progress.

 

[sgallaty]

Pressed both exhaust valves out - the valve guides aren't bad. If a valve slides freely and holds a seal when I cover the valve guide hole, it's good as far as I'm concerned.

I was very lucky and the valve press that I scored actually works for these heads. It's a 'loaner' from advance auto parts.

There's very little clearance for compacting the spring, and it hits the head as you all know.

I'm surprise the head is in such good shape considering that bizarre buildup on the cylinder wall.

I'm going to soak the heads and valves in molasses water after having them soda blasted.

I wasn't going to bother labelling the valve #s - is that bad? I don't really care and don't expect it to matter which exhaust valve goes in which slot. Anyone disagree vehemently?

 

[Maddog Marty]

sgallaty: Really interesting...thanks for sharing. I've got one coming from Michigan that I am eager to get and tear into...it's not bad at all, nothing like your project. I am living vicariously through yours! BTW, where in California are you?

 

[sgallaty]

In austin tx now.

I actually gambled on this bike - bought it with a parts carb for 200, and I think I got what I paid for. I'll have assembled it from the bones of many when it's done. Frankenbike.

Really though, it's just the jugs and pistons that are 'bad', so far. The heads... enh. we'll see about the heads.

All told, a bottom end with 7500 miles on it, no metal flakes and an intact chain tensioner is worth this.

 

[sgallaty]

Just ordered a few more odds and ends - ATU rod, and also ordered some jugs off of ebay that looked to be in primo condition.

Going to go over to my buddy's house tomorrow and drift out the valve guides. aug 1 is coming up and my new budget =)

about to pick up an angle grinder, welder and compressor/shop vac for some blasting fun

 

[sgallaty]

drifted out the valve guides tonight with dogbunny's help. Going to toss the head in the soup shortly and get some of that rust off.

 

[XSLeo]

Do the engine and frame numbers match? If so that may indicate the speedo has the right miles. If they don't match then the engine may have any number of miles. Never can really tell. Very easy to swap engines and gauges.
Mikes has new sleeves to replace yours if they can't be used. Pistons, rings and such are easy to find. The 750 kit is a nice thing too.
Leo

 

[sgallaty]

Update:

Buddy I bought the bike from gave me another engine to salvage (this one burned up the bottom end. PO had put too much permatex in it and clogged oil journals)

Trashbike's engine has a near-perfect bottom end, I'm using the valve guides (tested good), valves, lifters and possibly one of the two pistons from "Freengine"

I drifted the old bad valve guides out with a cement setter that was handy. I'm going to get an actual valve guide drift to get the good guides out and put them in my head, to avoid any chance of damage.

Only big question left unanswered right now is what of the pistons I have can I use.

Getting closer!

 

[DogBunny]

There is an interesting story here.
I sold sgallaty trashbike, and I also gave him freengine.

I bought freengine just a couple of days ago for $60. I got a bunch of really good stuff really cheap from the dude, like two perfect BS38 carbsets for $30 each. I got so excited, that I never noticed that freengine was seized. When I found out I was bummed until I started taking parts off of it. Everything was perfect. The starter gear looked almost brand new. The plastic chain guide thing under the drive sprocket looked almost brand new too. Very little wear on the drive sprocket. The rotor and stator ohmed out the best I have ever seen. The carb boots, clutch, and starter motor were all good.

So, I figured that I got way more than the $60 that I paid for it, which is why I just gave it to sgallaty, who I knew needed internal parts.

We figure the engine has less than 5K on it. The mystery is why it was rebuilt. Don't know, but whoever re-built it went crazy with Permatex Utra grey, which he shouldn't have been using to begin with, and it clogged the oil journals and killed the engine.