Day 14 - Dilemma

So back bringing engine parts back in the house, so I figure even though I don't have the correct (according to the service manual) colour coded bearings in there, I figured I would go an measure the clearances anyway using plastigauge, and I'm expecting them to be totally out of spec hence the need for new bearings of the right colour code.


So...to my surprise - all the clearances are within spec!! In fact they are slightly on the tight side, around 0.038 but no way near the service limit of 0.050. But they're not below 0.020 which is the starting range according to the manual! So now I'm in a dilemma. My main bearing clearances all check out even though I don't have the correct colour coded bearings in there according to the markings on the crankshaft and crank case! So what to do! Shall I just reassemble the engine with the clearances as they are and see what happens? I mean surely if the plastigauge reveals the correct clearances then I'm all good right? What to do....

Day 14 - Codes, Clearances and Numbers

So the remaining pistons have now been cleaned of most of the carbon build up. Number 3 piston proved to be quite a mission to get that clean with a simple soft pad, but got there in the end. Piston rings have also been cleaned. Before going back in they're going to need plenty of oil.


Lower crankcase is also looking good from the inside, in preparation for putting the lower half of the engine back together.


Now for a slight complication. Whilst my original plan was to simply take the main journal bearings in my old lower crankcase, and put them in the new lower crankcase, and then use my new piston rods, with my old pistons on the new crankshaft and put it all together - it appears it's not quite that easy, and that's mainly due to the main journal bearings and sizes. In the below picture you can see the codes AAAAB which indicate the crank case inner diameter size, and this has to be cross referenced against a similar code on the crankshaft in order to select the correct size main journal bearing.


Below you can see the codes for the crank shaft (new one), and it's different to my old crankshaft. My old crankshaft had the code L22222. So 2 of my main journal bearings are going to need replacing so that I achieve the correct oil clearance between the crankshaft and main journal bearings. Now looking at my existing lower crank shaft, I have 4 Yellow bearings and 1 Green one which correctly corresponds to the B code in the above picture. So I've just ordered a Pink bearing which corresponds to the code 1 on the crankshaft and code A on the crank case. But....there is another complication. My new lower crank case has different coloured bearings to my old lower crank case. This indicates that either the crankshaft that used to sit in there is a different size to my one or that the upper crankcase that was made alongside my new lower crank case has a different main journal inner diameter than my one. So basically my worry now is that I've got 2 crankcase halves each of which are going to have slightly different inner diameter sizes for the main journals!

In order to account for this issue, I'm going to use plastigauge and measure the oil clearances I have right now. I must do this on both halves of the crank case so when I bolt everything together I'll put some plastigauge on the main journal upper half, and some on the main journal lower half. They both need to be within specs otherwise the main journals will not receive enough lubrication. Preferably I would want both halves to have exactly the same oil clearance so that the crankshaft main journal is not rotating around something that's not completely circular (I know we're only talking hundredths of a millimeter but it really does matter if I want this engine to last a long time).

My other concern was that would be matching incorrect crank pin bearings and piston rods with the crank pins on my new crank shaft. However thankfully all the codes are the same for the crank pins so I don't have to worry about that. When I switch over the pistons an use my old ones I must make sure to measure the piston pins outer diameter and piston rod inner diameter and ensure the clearance is within service limits. 

Day 13 - Piston Ring Check

So whilst I wait for more parts, let's check the piston rings. This is done by inserting the piston rings into the corresponding cylinder and ensuring it is inserted perfectly square by using a piston to push it down a bit, and then using a feeler gauge to measure the thickness of the piston ring gap, where the 2 ends meet. Thankfully the piston rings, at least on number 2 cylinder are all within specs.


Deliveries! My replacement crankshaft and piston rods arrive. Time to unpack them and examine.

Time for a Task List

It's quite easy to be overwhelmed with what has to be done in order to bring this project to some sort of completion without it becoming a collection of parts in my garage for years to come. So here's what is left to be done.

Clean the remaining pistons.
Finish cleaning the lower crankcase
Mask the lower crankcase in preparation for painting.
Paint lower crank case with multiple coats.
Measure the piston ring end gaps - determine if new rings are needed.
Clean upper crank case
Mask upper crank case in preparation for painting.
Paint upper crank case.
When new rods & crank arrive:

• Measure piston pins and compare to my existing piston pin. Determine if the clearance is within service limits.       

• Use plastigauge and measure new crank pin bearing clearances and measure crank case bearings using existing bearings with new crankshaft. Determine if the clearance is within service limits.

Clean oil sump
Mask oil sump ready for paining
Paint oil sump
Use compressed air to blow out dirt from oil channel in lower crankcase
Install gear selector drum in lower crank case & lubricate
Install pistons with new rods & new crankshaft in upper crank case
Install transmission in upper crankcase & lubricate
Order a full gasket set
Combine the upper and lower crank case.
Clean oil strainer
Reinstall oil sump.
Check oil pump clearances and determine if replacement is necessary
Reinstall oil pump
Reinstall stator flywheel & clutch housing and clutch
Reinstall crank timing sprocket
Clean timing cover & repaint
Clean clutch cover & repaint
Clean stator cover & repaint
Clean oil cooler and repaint
Order new oil cooler bolts
Install oil cooler.

Cylinder Head Service
Remove valves and clean & check and remove carbon deposits
Reinstall valves and check installation
Clean cylinder head intake and exhaust ports.
Repaint cylinder head.
Install cylinder head using new gaskets & ensure correct timing
Perform a valve clearance check & service if necessary using new shims
Order a new thermostat (old one needs replacing).
Clean valve cover and repaint
Install valve cover with new gasket.

Engine Complete

Remove rust from front of bike frame and repaint
Remove ohlins shock.
Remove rust from shock spring and repaint
Determine if Ohlins shock to be serviced by an Ohlins specialist
Remove rust from head light, mirrors and lower fork mounting clamp

Reinstall Engine
Order new Pair Valve pipes & Gaskets & Bolts
Order correct engine oil
Order correct oil filter & install.
Fill with OIL!

Carburettor Service
Clean & check carbs - dismantle if necessary.
Reinstall carbs after service
Clean air box & radiator, remove rust & repaint if necessary.
Order new stator wiring connector

Fill with engine coolant.
Engine first start.
Get air out of coolant and ensure coolant at correct levels.

Service front and rear brakes & clean - replace brake fluid, determine if new pads are needed.
Examine wiring and get brake light working.

Clean wheels.
Order new Tyres & Install



Things to Order
Order a full gasket set
Order new oil cooler bolts
Order a valve spring compressor
Order a new thermostat (old one needs replacing).
Order new Pair Valve pipes & Gaskets & Bolts
Order correct engine oil
Order correct oil filter
Order new stator wiring connector
Order new Tyres

Day 12 - Cleaning

Not much apart from cleaning has been done whilst I wait for more parts - specifically I'm now waiting for a new set of Piston Rods, another Crankshaft and Pistons. Hopefully they include the crank pin bearings and some piston rings. Although I'm thinking when I put this all together I shall use my existing pistons, but use the new rods that are delivered. This way I'm not putting rings or pistons back in that haven't worn to the cylinder the same way. But the below pic is number 2 piston that has been cleaned of all carbon deposits - to clean I just used a soft green scotch brite pad and some gunk cleaner.


I do a little experiment with Coca Cola, I've been reading that it's good for degreasing so I pour a whole load in a box and soak part of the lower crank case in it. It didn't really do anything so to clean that part I've resorted to using some wire wool (on the outside only!) and more gunk cleaner. A tiny little watch screw driver was also used to get into the tiny little crevises of the lower crank case.


The lower crank case section - the gear lever section after a night of scrubbing and cleaning. It's not looking too bad and is probably ready to be painted with the VHT paint I have.

Day 11 - Transmission Countershaft

So now it's time to have a proper look at the transmission. This time I do this indoors in the comfort of a nice warm room and an old towel laid down on a table. At least this gives me some space to lay down all the parts in the order I remove them.


At this point I'm very much following the service manual ensuring each part is where it should be, and I'm going to put this back the correct way afterwards. Transmission countershaft looks to be in good shape.


The only thing I struggled with a bit was the snap rings, as they are pretty tight little circlips that need to be pried over the shaft. Maybe it was because the circlip pliers I was using weren't really up to the task but got them all off in the end.


Transmission countershaft dismantled below. In order to measure each of the inner and outer diameters of each othe gears and their relevant bushes, I decide to label each gear and count the teeth.


After doing some measuring of the inner diameters of the the gears, and both the inner and outer diameters of the bushings - they all fell within the service limit and none needed replacing. So time to put things back together.


All back together, next is to have a look a the main shaft.

Day 11 - Piston & Transmission removal

So after doing some more reading about bearing replacement it appears there are some markings on the end of the crank shaft (shown below) that indicate the diameter of the respective crank pins, and therefore allows me to purchase the appropriate sized bearing, apparently there are colour codes when ordering which represent different diameters. The markings on my crankshaft look pretty difficult to see but I can make them out.


So I go ahead and remove the pistons - from the top of the engine as the manual states. It's quite obvious to see the discolouration of number 2 piston rod.


Below is the upper crank case with the transmission removed, and pistons remove - at another time I will properly give this a clean and get all the sludge and grime out from the inside and then clean and paint the outside. I want to clean any old oil sludge as any new oil I put in there will just get contaminated by old oil sludge.


The pistons will also need those carbon deposits cleaning off so they are looking good again, another task is to examine the piston rings and determine if they should be replaced.


This is what concerns me (below). These are the bottom of the piston rods - the one on the left is the piston that had the destroyed bearing and it's quite obvious to see lots of scouring and damage but what really concerns me is that there is no oil lubrication hole like there is on the one on the right! I can only conclude that the bearing has become welded to the bottom of the piston rod and thus covering up the hole. I did try to stick an appropriate sized tool in the upper park of the hole but it wasn't going through or dislodging any welded bearing. I could drill it out, but maybe a new piston rod is in order. After a bit of reading, this kind of thing can happen if the crank pin bearing is not installed correctly, i.e. the hole in the bearing should line up to the hole in the piston rod and makes sure the crank bearings get lubrication.


In the picture below it's quite easy to see the discolouration of number 2 piston compared to number 3.

There is also quite a bit of damage on the bottom of the number 2 piston rod. The more I'm looking at this the more I'm thinking a new piston rod is in order. Let's see how much those are.

So now time to remove the gear selector mechanism that's still in the lower crank case. As this mechanism will need to go into the replacement lower crank case that I have in the house. One thing to note is that there is a pulley looking thing which is spring loaded into the grooves on that cog looking thing with pins sticking out - very important and ensures proper gear selection.


Gear selector forks are below. It's worth noting that they are labelled L C and R for Left, Center and Right and must be installed in their proper locations.


Below is the gear selector drum which in an earlier post I mentioned resembles the inside of an old music box. When you shift through gears you're turning this drum which positions the selector forks in the different locations to move the transmission gears to their right locations to engage the correct gear.


I've brought the transmission inside the house now for proper disassembly and examination of that as a separate piece. Another post to follow. Hopefully the transmission is in good order but maybe not - I noticed when playing around with it there is some wiggle in some of the gears so maybe this indicates a bearing or two needs to be replaced.

Day 10 - Crankshaft Examination

So now the crankcase is split, the next task is to remove the caps for the piston connecting rods, and remove the crankshaft and examine the bearings. Now one interesting thing I noticed on number 3 piston was that I was able to move the piston up and down like it was loose on the crankshaft - that indicated to me the bearing holding it firmly in place must have been destroyed, and that gave me some hope as to where those mashed up clumps of metal came from.


So after removing the caps for the piston connecting rods, low and behold I find the culprit (below). As you can see number 3 Pistons bearing is completely destroyed and only a small portion of it remains. You can also see that the rod itself and that section of crankshaft is a slightly darker color then the other piston caps and rods.


So I remove the crankshaft and place it on a towel along with the destroyed bearing. Whilst it's obvious this will have to be replaced, I will have to research if a new bearing is as simple as a swap with a new one as there must be a reason why that bearing had gone and not the others, but I also noticed on the piston rod for that piston there is no oil channel hole like the other piston rods have so maybe this has something to do with it - maybe that bearing was not getting any lubrication.

 
And below we have the crankshaft removed with the destroyed crank pin bearing sitting below the crank pin that it came from.

Day 9 - Splitting the Crankcase

So after getting my M20 x 1.5 bolt in the mail, I spend this evening giving it a go on the flywheel and using an Air Impact Wrench - screwed it into the larger thread into the flywheel and the thing popped right off! Easy! I stuffed some paper towel in the hole so I wouldn't damage the shaft it was sitting on.


So now from the clutch side of the engine we can get a good look at the oil pump and the little chain that drives it. You can also make out on the lower left the gear selector mechanism as you shift up and down through the gears, you're actually turning the little spindle with little pins sticking out (below)


Using some long nose pliers I was able to remove the clutch holder and the main gear. That's the gear that connects the crankshaft to the transmission. The rod underneath is the gear selector which would normally connect to the gear shift pedal.


So after removing the oil pump, removing the cam chain and its little slider and removing the timing cog (the little cog that looks like it's missing half it's teeth) I was ready to undo the crankcase bolts and pull the thing apart. It came apart pretty easy and it only took a light tapping of a rubber mallet to break the seal free. One thing to note was as soon as I pulled apart the crank case I noticed that the gear selector drum actually sits in the lower crankshaft whilst the transmission itself sits in the upper crankshaft. There are also 3 gear selector forks which are positioned just between the correct gears. I had the transmission in Neutral when pulling this apart and the transmission gears look completely centralised in neutral with the center selector fork going in the center gap and the other 2 going either side.


A close look at the inside of the upper crankcase. The underside of the pistons look good and it's nice to get a close look at the crankshaft itself. I'm still searching for a mashed up bearing or something thats caused all of those clumps of metal in the sump.


A close look at the 6 gear transmission. You can see how the gear sizes vary slightly from the input shaft and output shaft changing the gear ratios between the input and output shafts. Fascinating stuff.
However I noticed another clump of mashed up metal in the transmission section! So I have a feeling there is a bearing in there which has been destroyed. At least that gives me a clue as to where to look so it looks like I'll have to dismantle the transmission and examine each part very closely.


Below you can see the gear selector forks, and underneath those what looks to be a drum which resemble the inside of an old music box! Which different etched out patterns, so I'd imagine depending on the gear you select it positions the forks slightly differently so it engages the correct gears on the transmission.


Below we get a close look at the crankshaft and the underside of the pistons and connecting rods. I'll pull all those out and apart next. It'll be good to look at each piston closely and examine the piston rings and bearings.


A very educational session and really cool to get a close up look inside the engine and see all the inner parts for real. I think next on the agenda is more reading about how to service the transmission, and the pistons / connecting rods and crankshaft and bearings. I'd also like to clean the upper and lower crank cases on the outside and repray them with a nice engine Enamel. I must also remember that when unbolting the lower crankcase there are different bolts of different sizes that go in different holes so hopefully the service manual illustrates which size bolts go where, but incase they don't I've laid out the bolts in the order they came out of the lower crankcase.

Deliveries!

I love it when stuff arrives! The M20 x 1.5 bolts have arrived which I got from ebay for £4 which should now enable me to remove the flywheel. Awesome.













But also (below) A replacement mid crankcase section! Phew! It looks to be in pretty good condition other than a whole load of grease and grime all over it so it needs a good clean - I may even repaint it (on the outside) with some nice looking engine enamel. It's crazy when you think brand new from Honda this part is £1800, but from eBay used it was £20! Bargain! Also the dowel inserts for the oil cooler have also been left in - as I destroyed my ones.


Aaaah and look! Nice and NOT cracked. This was the section I destroyed by my excessive hammering on the oil cooler - Great! Things are looking good again for this project so all we need to do is strip the engine down completely, and do a full overhaul before reassembling with this new crankcase lower section.

Update

This isn't really any time spent working on this project, but just an Update entry whilst I wait for parts and bits to arrive. However I think it's good to write about what I've learnt during the 'downtime' sessions whilst I read through the service manual to better understand what I have to do next, but also gives a chance to clean up the garage as it's a total mess.

It's very easy to get out of control with tools and parts and bolts all over the place, and knowing me I will eventually forget what all the bolts are for and where they are supposed to go, so before I forget that, I decided to get myself some sandwich bags and put all of the different portions of bolts into separate bags - e.g. Clutch cover bolts, camshaft bolts, etc... and label the sandwich bags so that I know where everything is and it's all nicely stored in these little boxes. At least when I come to rebuilding the engine (whenever that will be) I know exactly where all the bolts and small pieces are.

But just to recap - the next stage is to remove the flywheel on the stator side of the engine, and remove the clutch housing on the clutch side - once I've done this I'm ready to follow the procedure to split the crankcase.

I was doing some research into how to get the flywheel off the rotor and it looks like there is a M20 x 1.5 bolt that can go into the fly wheel which you can tighten with an impact wrench which will cause it to push up against the rotor and hopefully release the flywheel. I was going to order a proper flywheel puller, but it turns out all I need is an M20x1.5 bolt to go in there with an impact driver and that should do the job. I'm going to put some plastic in between the M20 bolt and the rotor so I don't damage the rotor whilst it's trying to pull out the flywheel.

Day 8 - Came close to giving up

What a night this has been - problem after problem seems to keep occurring with this engine, and I'm getting seriously frustrated at the number of snapped bolts due to rusted - seized up bolts. So goal today was to remove the cylinder head in preparation for the new one. However before that I wanted to remove the oil cooler so I could get behind it, and clean up the engine with a wire brush and make it look a little nicer and also check out the oil coolers insides and make sure thats all according to spec.

The first challenge - the oil filter. That thing just wasn't coming off using the standard oil filter wrenches, band wrench - so considering it's going to be thrown away anyway, I ended up piercing it right through with a tyre spoon and then using that as a wrench to eventually get it off. That was way tighter than it should have been!


The next challenge - the Oil Cooler. This thing again just wasn't coming off and that was because of yet another bolt I ended up snapping due to rusting / seizure inside. So I try multiple attempts to get this thing out.


I even trying welding on an old pair of pliers onto the snapped bolt and using that as a wrench, but no that ended up just shearing off another portion of the bolt leaving me with an even smaller bolt stud to work with.

So at this point, I conclude that the oil cooler is going to replace, and out comes the sledge hammer. Targeting just the oil cooler only, I violently smack at the oil cooler until it breaks off.



The casing for the oil cooler now has a nasty crack and the bolt portion is destroyed. Below you can see the oil cooler in pieces. So finally got the thing off, but at what cost. It's at this I almost give up on this entire project and consider searching for a new engine for this bike...


Yup, I ended up breaking portions of the crankcase. At this point I was pretty soul destroyed and wondering what else could I have done in order to have got that snapped bolt off, although in hindsight I believe an impact wrench would have been the answer and probably would not have sheared the rusty bolt off.


So I go inside, have something to eat, and have a good long hard think about the mess I've made and if there's any way to rectify it. Onto eBay - only to find out I can get a replacement crankcase lower section (it was the lower crankcase portion I had destroyed) for £20! Ordered. Also a replacement oil cooler has been ordered. These aren't new parts but used parts from another bike.

So now I've got a new lower crankcase on the way - it's time to think about what it's going to take to replace this. I fully acknowledge the engine has to be completely and utterly stripped down to every piece in order to do this - so let's begin.

First let's remove the cylinder head...


Camshafts come out...It's worth noting that I will use the caliper and measure the exact wear on the camshafts I have already and the cams that come with my replacement cylinder head.


The cylinder head is off! (below) The cylinder head bolts were on tighter than I expected and required use of the breaker bar for extra leverage. However I wasn't too worried about them snapping off as those bolts are inside the engine and get plenty of oil. It's interesting to get a look at the top of the pistons (and nice to know I've got them at Top Dead Centre).


So now the stator cover has come off, and starter gear has been removed...(below)


But of course it wouldn't be a complete evening if I hadn't yet encountered ANOTHER snapped bolt situation - I wasn't even turning very hard on this it snapped off with my micro wrench. Although the Bonus with this one, is that the snapped off bolt is on the lower crankcase! Bonus - thats going to be replaced anyway so I don't care woohoo!


It's very easy to get out of control with the number of bolts and screws you can have left over. I usually am in the habit of putting bolts back in their holes once I've removed a part so I know where everything is. But in the below picture you can see the Clutch has been removed, starter gear and the bolts for the Oil sump can be seen, Camshaft bolts, valve cover bolts, and clutch cover bolts.


So this is interesting...When removing the oil sump, I've discovered a whole load of mashed up metal bits. Now I was under the impression that normal engine wear produces tiny little iron filings not massive clumped up bits of metal in the sump! Something tells me there is either a destroyed bearing or part that I've yet to discover. Perhaps it's a blessing that I'm stripping down the engine. I also discovered the thermostat at been bent in the open position so the engine would have possibly been running too cool all the time. Must remember that the cylindrical part in the sump is a pressure relief valve (which must be tested), and the oil strainer which must also be cleaned properly.


Now the sump is removed we can get a good look inside the engine from the underside...


So time to call it a night. In following the service manual there are a couple of extra tools I now need. One is a clutch puller so I can get to the fly wheel and remove that. Another tool is a couple of pairs of long nose pliers so I can grip a small washer in the clutch side and pull out the clutch holder.


Overall today has taught me quite a few things. First things first that if I suspect a bolt is rusted inside I'm going to be using the impact wrench on it as the impact force rather than the twisting force of a normal hand wrench makes it far less likely for bolts to be snapped off. It's really interesting to see the inside of the engine, and see the condition of the pistons. There is a black sooty deposit on the pistons which comes off really easily so those pistons look like they will clean up nicely. I must remember to order a whole new gasket set - especially a crankcase and cylinder head gasket - the mating surfaces must be cleaned throughly before assembly. I'm still concerned there is a partly destroyed part inside the engine leaving all those metal clumps in the sump. Next task is to order the tools I need, and do a bit more reading on what to take apart next in order to split the crank case.