Piston Rings

Just a quick update, things have been on pause for a while here but with a random ebay check I was able to find a set of 2 piston rings, the elusive ones I have been having problems finding. So now I have 3 sets! wooho!

This means at my discretion, I can go back to rebuilding my original engine, or I can continue re-assembly with my donor engine... decisions...

Hopefully soon I will get back into the swing of things. My seat just needs a little more filling and then paint, I received an all balls bearing replacement for my steering stem too. So many parts, so much to do...

Valve Job

Little late on posting, but a couple of weekends bag I finished up on my valve lapping job.

Step 1: Cleaning the valves and head

This took a long time and a lot of methods. At first I soaked the valves in sea foam, then scrubbed with a brass brush and whereas this helped a little, I was not making significant progress. In the end, I used a brass brush on the end of a drill for cleaning the combustion chamber. The valves, I actually put on my drill and used a small screw driver to scrape off carbon as the valve spun. This is probably making some purists cringe, but it seemd to work well without any visible damage that I could see.

 

 Step 2: With everything as clean as I can get it without spending many more additional hours than I care to, I went out and bought a lapping tool and some lapping compound.

After about a minute of lapping each valve I used some prussian blue afterwards to check the surfaces. The mating surfaces were looking pretty good. I assembling the head without the valve seals, tested for leaks with kerosene and came away without any. So everything looking good, I re-assembled with my new viton valve seals. Now I just have to get back to attempting to clean the gasket mating surfaces and I can get the head back on.

New Seat Build - Part 1

Ok, like a small child or a bird, I cannot focus on one thing at a time. I am revisiting the seat and have read so many wonderful threads of fiberglassing success that I think im going to try my hand at this. So, some florist foam, painters tape, aluminum tape, a huge mess and one angry girlfriend later, this is where I am at:

Change of plans...

So, in the interest of getting myself on the road a little quicker, i decided to bite on a local listing for a motor!

It came from a 79 kz400 B2, turns over and has equal compression across both cylinders, though not the best compression... At any rate, I'm hoping it should get me by. If not... well, I guess I have plenty of parts for my other motor.

I will be cleaning this one up a little then throwing it into my frame for this years riding season. I will continue piecing together the other motor and will wait patiently for piston rings. Tonight i set the valve clearances and dumped some seafoam onto the pistons to sit overnight. This weekend past I also discovered that kerosene is a miracle cleaner. Amazing shit my friends, amazing shit. No scrubbing, no sanding, nothing... Just a couple of swipes and I get results like this:

Brilliant.

Doing time

Still unable to find NOS rings for my pistons, so not much news to report here. This weekend i cleaned up the crank case halves a little. I have discovered that kerosene is my friend. How I cleaned anything before discovering it, I dont know.

Another session or two of cleaning and I will likely seal up the case. Part of me thinks I should replace all of the bearings but im not sure if that is necessary... Part of me is getting tired of this whole song and dance but i'll stick with it, even if it means I dont get to ride this season :(

Seat Build - Part 2

So with a little more time on my hands, I drilled out some holes in the two metal pieces and riveted them together:

 

After that, I cut up seat cover and mocked things up. I think with some foam and contact cement I should have a half decent seat made up here.

Seat Build - Part 1

So, while my engine sits in pieces and I wait for the magical Piston Ring fairy to be done with her vacation, I decided to make an attempt at building a seat.

I bought 2 pieces of 16 gauge steel from Lowes and using a combination of Tin Snips and a Dremel, I was able to cut out the shapes I needed. I bent the metal to shape using a large metal hammer and some pieces of 2 x 4.

Not looking too pretty, but hopefully once I have the pieces sanded, painted, then riveted together, it will look a little better. Then I can get some foam glued on and finish it all up with some Vinyl. Stay tuned.

Quick Update

Just a quick update, its been a slow few days on the rebuild front. I was able to find a replacement cam chain guide which I have fitted. I have a chain also, though I have yet to compare the two to see if it is worth replacing.
Did a little cleaning on the lower crankcase half and am waiting to hear back from some manufacturers on the availability of custom made piston rings.

One thing I did start on was making up a custom seat pan. My existing one was full of rust and the seat foam about fell off. Stay tuned for some seat updates soon. I picked up some 16 gauge steel sheet to paly with...

Balancer and cam chain guide removed

So, after 8 more bolts that did not come off without some coaxing with the breaker bar, I was able to remove the balancer assembly:

This allowed me to finally gain access to that crappy tensioner guide that is falling to pieces. It was not as simple as I imagined it would be to remove, so I had to improvise a little bit. To remove the main horizontal pin that holds the guide in place, you have to first remove a little vertical pin.

 I took care of this with 2 pieces of coat hanger wire, which I used to kind of pinch and lift the pin, which I could then remove with pliars.

With the retaining pin out of the way, I tilted the remainder of the crankcase to help it slide out, then used that stupid telescopic magnet thing I bought at Autozone years ago because I thought it was cool.

Finally found a user for the thing other than trying to grab metal objects from across the room :D

So here it is, the nasty looking cam chain guide that caused me to split the case in the first place. Its replacement is ordered, so once I have cleaned things up I do not intend to replace anything else within the case.

Wishful thinking I'm sure ;)

Case Split!

Well after removing the final crankcase bolts, some light prying easily separated the halves. Next up will be the balancer mechanism, so that I can get to the crappy cam chain guide that started me down this messy path.

Stuck!

So I hit an unexpected snag that has occupied the last 3 days of my garage time. When removing the external shift mechanism (to allow me to proceed with splitting the case), i came across a screw that was stuck tight.

I attacked it with PB Blaster and the impact driver for 2 days with no movement and unfortunately, the head started to get mangled in this process.

I decided to go and buy a butane pencil torch before going any further and for about an entire day, I heated the screw for about 30 seconds, then let it cool, lubed up, let it sit, repeated.

Each time after heating, I would use vice grips to try and turn the screw with no results at all.

As I have discovered with this motor, persistance is the key. Repeated cycles of heating, lubing, hammering and gripping finally yielded a positive result. The screw started to move and I was finally able to unscrew it, a couple of milimeteres at a time. Not the most accesible place for the vice grips.

Funny how a single seized screw or bolt can put you several days behind. F U screw!

Removing the clutch cover and clutch hub

The next step for me on my way to splitting the case is to remove the clutch cover. This was another stubborn one.

Using an impact driver to remove all of the case screws carefully, I then proceeded to try and remove the advancer per the instructions of the workshop manual. The 13mm bolt would NOT budge at all. After a little soak in PB Blaster, I brought out the breaker bar and got it off without any problems, then proceeded to remove the kickstart lever.

At this point, the only thing holding the cover on was the gasket and without there being any pry points, it was kind of hard to remove. I started by using a thin blade to try and get through some of the gasket material. Then I resorted to tapping on a piece of wood against the case, with a mallet. This broke the seal and after some gentle coercion, I was able to remove the cover.

With the cover removed, the clutch plate, hub, springs and friction plates needed to be removed. This simply involved removing 4 bolts and 2 circlips.

The sprocket and hub came off without incident. I am now that much closer to splitting the case.

Fail Piston

Looks good, doesn't it? The piston has been soaking in penetrating oil for a few days now and I still cannot remove the stuck top piston ring. That and the corrosion on this guy make me realize its time to source a new piston. Fail.

Removing Valves - Part 2

Just received the 'genius' valve spring compressor and was able to get the valves removed on the old head without any issues. The 'new' head I have, the springs seem to be either a lot stronger, or rusted up somewhere. They are soaking in PB Blaster right now before I try to remove them again. Here are a couple of pics of the genius tool in action:

 Here I used duct tape to avoid scratching up the valve

Removing Valves - Part 1

Craftsman valve spring compressor = Good for intake valves. Impossible for exhaust valves.

Good job I have 2 cylinder heads to work with. The craftsman tool is kind of screwing up one of them. Different valve spring compressor now ordered...

Removing the Cylinder Block

 The KZ400 B1 has 4 pry points for removing the block, 2 on the left and 2 on the right. These served only to annoy me and worry me, as prying on these did nothing. Its easy to deform/break the soft aluminum when the block is stuck tight like mine was. In future, I will ignore the pry points until I have done everything else.

So, the next step was to squirt penetrating oil (PB Blaster) down the stud holes, since word on the street is that a lot of crap (dirt, rust) can accumulate in here and make removing the cylinder block painful.

With everything lubed up and soaking for a day or two, I would attack the block with a rubber mallet. Hitting on the front, where the chain tensioner rod screws in (it being removed at this point) at the back, on the sides at the top. Basically, you want to be gently tapping everywhere except for the engine fins, as I found after breaking off a couple.

The hammering and the lubing gave way to attempts to pry with pieces of 2x4 wood. I was all ove the above for about a week solid with next to no results. Lube, hammer, lube, pry, hammer, lube.

One member at the kz400.com forums advised stuffing some balled up rags down the cylinders (pistons at their lowest point), then bolting the head back on (not too tightly) then turning over the engine with a wrench. I did this until I could no longer move the wrench, so the rags were fully compressed in the cylinder. This did not seem to have done anything, but after I removed the head, I pryed on the left side and sure enough heard the tearing of gasket paper.

So in short: stuff balled up rags down the cylinder, put the head back on and manually turn until you can no longer turn anymore. Remove the head and try the pry points again. Rinse and repeat if necessary.

The rebuild, as it stands

Here is a brief summary of what is done, what is not done and basically all that has happened since purchase in September 2010.

The bike as purchased:

Strip down in progress:

-Frame stripped and powdercoated satin black

A good number of parts have been bought, including a fuel tank, wheels, carb holders, clubman bars and various other bits and bobs. So far the emphasis has been on disassembly and the replacement of aged/corroded/broken parts.