Day 26 - Engine Reinstall

So now the cylinder head is back on, valve timing sorted, and valve clearances checked it's time to put the engine back in the frame. I must admit this was one of the toughest jobs to get done successfully. The first challenge was to locate the engine under the frame without scratching too much of the little feet that sit on the oil sump. It was easy enough to get the engine under the bike without the scissor lift, but as soon as I put the engine on top of the scissor lift, it would not slide in as easy as the engine frame mounts got in the way.


Eventually got to the point where I could start lifting the engine up into the frame so the mounting holes align. I ended up having to lift the front of the bike over the engine so that the frame mounts didn't get in the way. My first intention was to get all the frame mounting holes to align perfectly and then start bolting all the engine mounting bolts back in. This wasn't going to work, so instead I got the front left hole to align and then bolted that on individually, and then I messed around on got the front right to align, and with the front of the engine mounted I could continue raising the engine with the lift so that the rear mounting holes would align. After that it was just a matter of putting the mounting bolts back through the engine mounting holes ensuring the spacing collars fit on the correct side, and then done.


It's nice to see the engine back in the frame again. Hopefully a working engine that will start and run! It's still looking pretty bare even with the engine in, so next step is to refit the oil cooler, then oil filter then fill with oil (yes engine still has just moly lube in there and some minor dribbles of engine oil in the cams).


Carburetter has to go back in, then the air box, air filter, and a new battery is needed. Exhaust system then needs remounting and as I'm getting rid of the pair valve completely I need to make up some blanking plates for the pair valve holes on the exhaust side. Still quite a lot to do before I can give it a first start. I've decided before working on other parts of the bike I need to know if the engine will start and run before I work on other things like the suspension and brakes and replace the tyres. Pointless doing any of that if I have to rebuild the engine all over again...

Day 25 - Cylinder Head Reinstall

So now the valves have been sorted out, it's time to put the cylinder head back unto the engine along with the nice new cylinder head gasket that arrived in the post the other day.


Before doing this however I made sure that the engine is at Top Dead Centre, so that helps me get the valve timing perfect.


It's looking like a whole engine again! Just need to reinstall the cams, and get the timing right...


Just a thought, when I reinstall the camshafts I'm going to check the valve clearances to make sure they are within specs. But...before I do this I thought it would be wise to note down the shims that are already in there so I know which shims I need just incase the valve clearances need adjustment.


Camshafts all reinstalled, and time to check if I got the timing right...



That would be a NO! Oh well first time I wasn't expecting to get the timing perfect, but it looks like I need to shift each cam maybe one tooth counter clockwise to get it perfect.





Ok done! Cam timing has been sorted out, all I had to do was remove the intake cam, but left the exhaust cam in place and then I could move the chain over one notch, and then place the intake cam one notch counter clockwise and I turned the engine round manually a couple of times and it feels smooth (although tight) and it goes around nicely! I could even hear the hiss of the compression as it hits the exhaust stroke - it's looking good. I've also checked the valve clearances and thankfully they are all within specs - some are +/- 0.02 out but thats within tolerance according to the manual.


So now it's looking like a proper engine again. I think the next task now is to think about putting the engine back in the bike and then we can start refitting all the other components like the thermostat, water pump, radiator, and so on...

Day 19 - Day 24 - Valve Grinding

So I've concluded that the cranking test I did last was revealing a very weak battery. So I've decided to continue and proceed with the cylinder head service, which now means removing the valves, cleaning the valves, valve seats and that whole area, and it also means lapping / grinding the valves to ensure that they seal perfectly in their seats when they are closed. So time for some grinding paste...



A valve spring compressor is an essential tool for this job. Basically a massive G Clamp which helps to compress the valve spring whilst removing the little cotter pins that keep the spring seat in place.



Valve seat and cotter pins removed, along with valve spring...



I must admit this was a seriously tedious and boring task. Many movies were watched in the background whilst doing this over several days.


Grinding the valve down using a hand lapping tool. Basically you can feel and hear the roughness of the valve as you turn it in your hand, and as you keep going you can hear it becomes smoother and smoother until it sounds near silent. Rotate the valve 45 degrees and do the same thing, keep doing this until it's smooth all the way round. And to do that 15 more times....



A few of the intake valves had this really nasty orange powdery stuff on them, and this was also present in the valve seats - not sure what this was but I cleaned it all out...




Some dirty looking valve seats before cleaning...





And Finally all done with all 16 valves! (5 days later). Most of the time I would do one valve at a time, but then I got a little impatient and did about 4 in one go and laid the valves out neatly so I would remember where everything went when I put it back together.



Now to fit the cylinder head back to the engine...

Day 18 - Cranking Test

So now I've finished putting together the lower half of the engine, the clutch, stator, and all the covers are back on, and the starter motor has been reinstalled so I decide to try and see if the starter motor can crank the engine over when given power from the battery - my concern is that when I try to turn the engine over myself by hand it feels very very tight and if I compare that to say my Ninja, it's almost effortless to turn that engine over so I kinda have an idea what it should be like. So here's the lower half in it's current state but I suspect it may have to be rebuilt again and main bearings replaced with new ones.

I've even made a video of me trying to crank the engine over by applying power to the starter...

Day 17 - Lets get this done already!

You know it's one thing to have an idea in your head and get all enthusiastic about it, and a completely different thing to put that idea into practice. I'm experiencing this with this project. Although I must admit I'm not the most patient of people, and a lot of this project is..well....mundane tasks - a lot of scrubbing, cleaning and it takes a long time! So saying that it is rewarding to see it all nice and clean. However I really am looking forward to seeing if this thing will ever start again. So the engine currently stands in the garage like this...


So time for more cleaning - this time the cylinder head. I bring the cylinder head inside and grab the Scotchbrite pad and start scrubbing.


But then I got bored and completed only half of the cylinder head and the valves still have to come out and be checked out.


I'll be honest. Doing a full engine rebuild like I'm doing here is a LOT of work. A Lot for one person anyway, and I can really only stand a couple of hours in the garage at a time before I need a break from it. Thats partly why I bring parts inside (manageable parts) So I can clean them whilst watching a movie in the background.

Today the clutch has also been reinstalled and the Oil Pump has also been installed. That should have been the other way round as the Oil Pump went in first. However one of the things that discouraged me slightly was when I started to try to turn the engine by hand. It was very VERY tight. I could just about do it with a 3/8 inch wrench and then I kept going for a couple more revolutions and it got easier, but I'm not really sure how tight it should be when turning and thats with the cylinder head off!

Although been doing some reading and apparently it's normal for the engine to feel tighter to turn when using things like moly lube to grease when putting it back together. It's a lot thicker than engine oil and makes it feel harder to turn.

Although good news is a got an scissor lift delivered today, so that means when putting the engine back in I'm not going to be struggling like mad to get the engine raised up and aligned with the mounting bolts on the bikes frame so hopefully that job should be much easier.

Really just want to get this engine finished, and get the bike started - but that will come soon...

Day 16 - Lower half Assembly

So last night after installing the pistons, it's now time to get the crankshaft and transmission re installed. Before installing the crankshaft I lubricate all of the main bearings and crank pin bearings with Moly Grease. Lith-Moly Grease from halfords. Basically the same thing as what the service manual says to do. Below the crankshaft is installed and transmission installed into the upper crankcase. One thing to note. Before doing any of this I measured the bearing clearances with Plastigauge just to make sure the crank pin bearing clearances were within spec, and also I measured the main bearing clearances on the upper half and they were also within spec. This gave me the go ahead to start reassembly.


In the below picture you can see lots of Moly-Grease has been applied to the bearings. As the lower half of the engine is going to be sitting in my garage for a while it's best to use grease thats going to stick for a while rather than engine oil that will just run down over time.


So now in the below picture we now have the upper and lower crank cases combined. The gear selector mechanism has been reinstalled in the lower crank case and the gear selector forks have been placed in their proper positions in the transmission. Proper gear selection has been tested and it looks good. The gear selector bar has also been installed. I've applied heat resistant copper gasket to the mating surfaces so that should stop any potential oil leaks...


Another view of the engine internals from the underside with everything reinstalled. Fork selectors on the transmission properly positioned and all bolts have been torqued to spec.


So now the lower main half of the engine has been reassembled, it's time to start thinking about reinstalling the oil sump. If you remember from previous posts the oil sump was soaked in oil sludge combined with the remains from the chewed up crank pin bearing. So now all that has been removed, and the oil sump and oil restrainer has been cleaned...Next thing to do is reinstall the oil sump and seal the mating surfaces.

Day 15 - Installing Piston Rods & Pistons

So after the dilemma I've been having about what to do with the main bearings I think I've decided what I'm going to do. I'm going to measure again the clearances using plastigauge, this time on the bottom and the top and also measure the crank pin bearing clearances, and if they check out (which I'm sure they will I'll be putting everything back together. So in preparation for reassembly, I've taken the piston rods from my new pistons that came in the post the other day and I'll put them on my old pistons. My old pistons are nice and clean and the rings I have have worn nicely to the cylinder bores so no need to change that as the end gaps are all within specs too, so I know the piston rings are good.


Below....disassembling each piston assembly and replacing the piston rods with new ones so that the rods and bearings match the new crankshaft I'm installing. One thing to note that with my old pistons getting the piston pins out on a couple of them was a real pain! had to hammer them out lightly with a plastic rod.


Below...measuring the outer diameter of my piston pins. Looks like they all check out.


So now my pistons all have nice new rods and are ready to go back into the cylinders. Let's give the cylinder upper crankcase a clean from all the old oil sludge remains and let's reinstall those pistons.


Below...number 1 piston installed and number 2 piston about to be installed. Piston Ring compressor from halfords works a treat. The IN mark on the pistons must be towards the intake side of the engine. IN = Intake.


All Pistons now all installed (below). I was actually hoping to have the crankshaft installed too and all plastigauged and measured. However before installing the pistons I wanted to clean the mating surface of the upper crankcase where it meets the cylinder head. In the below pic you can see it's all nice and clean and rid of all the old remains of the old gasket that was there. To clean I used a soft scotchbright pad so not to scratch or scour the surface. Wire wool, or anything too abrasive is a big no no!!



Tomorrow time for the crankshaft to go in and be plastigauge for and checked for proper crank pin and main bearing clearances before installing the transmission and getting the two halves back together.