Honda 'all of the cxs'

[yoeddynz]

I've been looking for an ideal first CX since selling my Goldwing a few weeks ago. I was tempted by some fairly spendy ones in the 5k range.  I was chatting to a mate from the next valley about bikes, mentioned cxs and he said his brother has a couple...

...and he is planning to sell them.

Cool. One of them is a CX400E. Not sure on the other and I would have to wait for 10 more days because he's away. 

So I've been counting my sleeps and then on Monday another cx popped up for sale locally - for only $500! But it has a seized camshaft and is in bits. In other words a proper project.

Within a couple of hours four different mates had sent me the advert link. I contacted the seller asap. I said..

"I'll buy it! Can I collect it tomorrow?"

"yeah man, no probs"

Great. So on Tuesday this old thing followed us home..

Off the trailer and inside. It might only be 'late summer' here in sunny west Tasman but its fresh enough to get the workshop fire cranking.

Bike has been lightly cafe'd but came with all the original parts included along with a few new Honda bagged spares..

Original speedo matches the recorded mileage that shows up online..

I was blown away by the brand new fan..

 

Following morning I freed up the sticky front calipers which luckily had nice clean pistons. Nice to see bike already fitted with braided front hoses! I plonked the seat and tank in place and took some pics..

Hannah helped me remove the engine and lift it up onto the bench. I had to get this pic..

I started looking into this 'seized' camshaft. Previous owner said it started leaking oil out around cam seal and making awful sounds. After turning the bike off they couldn't turn it over. They took it to a mechanic who tried to remove the tacho output/camshaft front bearing block. He got it to spin round but it wouldnt come off and broke the casting. He decided the job was going to be far more involved than they wanted to spend. The bike sat a few years and now its mine.

Damage here...

Picture from FSM of parts..

 

I managed to spin it round but I could see the spiral cast into the camshaft that turns the tacho gear is damaged. 

You can see the spiral here..

My guess is that on of the teeth had broken in there and made a mess of things. The camshaft was forced sideways and made a mess of the bearing bore. I tried everything thing to remove it without having to resort to further disassembly of the engine but no luck. I'd got the tacho pinion out but the alloy housing was all burred on the engine side of the cam spiral. there's a good visible .5mm (.020") of movement on the cam so the clearance is far too much.

So I will pull the cam out. Hopefully the bearing journal is ok. I can clean it up in the lathe if just scuffed with alloy. I'll fabricate a new cam bearing block and bore it to get the exact factory nominal .0015 

I've popped the rear cover off and this is where I'm at as I'm now away visiting mum.

Great news is the rest of the engine appears in good condition. Very clean inside suggesting regular oil changes. The cam chain looks in good condition with plenty of life from what I can tell. 

I'm hoping I can carefully remove the headbolts, pop the top rockers off and replace the bolts with some spacers i'll machine up. Then the heads are still clamped while I remove the pushrods and flip the engine upside down. The cam followers will swing away from the cam and I can extract it.

Ultimately if the engine is a good runner I'd be happy to give the heads and valves a birthday clean but I really dont want to pull it down further until I get a full gasket set. I'm also waiting to find out about the other potential cxs on offer.

[jessemk2]

Need to add vintage honda wing logo to the shop sign

[yoeddynz]

Yeah definitely that's going to have to happen eh! 

[yoeddynz]

Work on this stopped as we went away. Got back home and discovered I needed to buy or make some tools for dismantling. I dont mind spending time on such when I know there will be more of these engines to play with.

I made a toothed cog holder. The usual thing I've read is to use a 2 cent/1 penny coin and jam it in between the teeth. Just doesn't seem right nor can I afford such extravagant throwing about of money when I have steel sitting here..

I also needed a really deep 27mm socket for the camshaft nut. It was the weekend and the only one available at Repco didn't look deep enough. I remembered I have an old 1/2" socket set I've robbed a few sockets from. Luckily there was still a 27mm so it got the chop and extension treatment..

Because my initial intention is to try and remove the camshaft without removing the heads I machined up some spacers that would replace the rocker shaft pedestals...

This way I could carefully crack off the headbolts and fit the spacers, so hoping not to break the head gasket seal. From what I have read the original Honda gaskets will probably hold tight. At the mileage this engine is I presume they are original.  If the camshaft is ok I will probably pull the heads anyway, buy a full gasket set and give the top end a birthday.

Spacers installed, engine was flipped upside down and I was finally able to extract the camshaft, complete with its front bearing that refuses to budge..

Into the press...

It still wont budge. I didn't want to go overboard with pressure. The damaged worm gear on the camshaft must be holding it but I didn't know how. Something really jamming it. I spun the remains of the spiral off...

Now back in the press and the bearing housing finally popped off. Along with some small bits of metal. Oh dear. I actually laughed. Hannah was in the workshop and she gave the same 'faaaark - I didn't expect that' expression too.

ZOOM IN..

ZOOM IN FURTHER...😐

Wow. How the fark?!! The bearing housing is understandably rooted as well..

So...I think I might need a camshaft..

I'm not surprised the engine made funny sounds/leaked some oil 🤪 I can only guess that it got super hot from a clogged oil way but you'd think the alloy housing would have disintegrated first? I don't know. 

I believe the camshaft I need has to be from a later bike as it has holds the valves open a few degrees longer than the early ones. If I can't find one easily then I could just skim this one down and shrink fit a sleeve, then re-machine. Its not a highly stressed cam and I was intending to make a new housing anyway so it can suit anything.

Hopefully I'll find something plus I have yet to find out what of the bikes I'm hoping to secure locally. They could come with spares.

 

[Snoozin]

You got one. You know my thoughts on these lemons but I'm glad you've unearthed the bargainous opportunities.

[yoeddynz]

On 19/05/2026 at 11:35, Snoozin said:

You got one

But wait there's more!!!

 I decided to finish stripping the engine because the mess from the cam bearing would have been a ballache to clean out plus I really needed to see the state of the bearings elsewhere. If they were ok I could also properly clean everything, check the valves and start a fresh.

Gearbox is in fine condition..(I instantly pictured and started engineering in my head how this very neat compact unit could be used as the basis of a sequential box innards for a small car etc)

Crankshaft is fine. 

Big ends still fine..

Popped it on some blocks and checked the clearances..

About .0025"  (service limit is .0031")  They could be used as is and I'd never be worried but if there's available bearings at sensible prices then I could pop some in. I couldn't see any obvious colour markings though.

Before I get too excited I still need to sort out a camshaft/front cam bearing. So in the meantime I have bought some more plastic storage trays and I'll stash the engine out of the way. I can clean bits up in between other jobs/procrastination excuses/purchases....

...like the following.   

Hannah and I took off in the Imp to look at two more local bikes  - ones a 650E, rego on hold but needing some tinkering. We drove the Imp there because the fella selling the bikes, as mentioned in my first post is the brother of a friend and his parents used to own an Imp.

 Anyway - the bikes. I'm quite tempted. The 650E has a damaged impeller stud thread on the camshaft. I think I can fix it though. 

  The other bike offered to me for free is a very rusty (holes in the lower frame) 400E spares bike.  I could always pinch the cam from this in order to rebuild this 500 engine that's still spread all over the bench.

Ideally I'll sort the 650 first because its otherwise all go, solid and rego on hold. Its really too rare/nice to do anything but restore back into use. I need to mull it over though because costs could spiral on a bike that has hard to get parts. 

  I'm very tempted to repair the rusty 400E frame and fit the 500 engine. This could be used as a basis for a fun project bike. And if the 650 didn't exist this is simply the route I'd be taking - just imagine the entertainment for you all as I start having to restore a frame that's half in powder form.

I'll report back with photos as soon as I've made the decision and have the bike/s in the workshop. 

650E be all like this but in white and not mint...

[yoeddynz]

So we went back to look at the local cx sports on offer.  When we arrived he made us some lovely strong coffee.  Then we wheeled the 650 out into the sun and I had a better look over it. I asked him how set he was on prices and he told me he'd been thinking about this for while since we last visited. He'd decided he was going to give me the bikes on the basis that he could see I was going to be the ideal person to fix the potential tricky camshaft/water pump/weak oil control ring issues/anything else from being laid up since 2017.

  I was blown away by this and told him I would do the 650 proud. I still insisted we pay him some money anyway and that we did. He's since been around to visit us for coffee and is a true gentleman.  He's now keeping and fixing up the GL500 Silverwing he'd been thinking of selling. I'll be more than happy to help him if needed.

So we loaded the two sports onto my cousins trailer we still had use of, filled the van with boxes of spare parts he'd stashed away and carefully drove home - elated with the exciting prospect of having both a lovely original cx650E to restore and a cx400s to potentially use as the basis of a custom build.

A lovely sunny afternoon to arrive home with new projects..

Unloaded them inside and that evening I could not resist but spend a few hours cleaning the 650 before snapping some pics. Its come up lovely and I'm looking forward to spending more time detailing it once its fixed and running ok.

These models have a great proportions and fantastic 80's Honda style.

It come with a black tank that he'd bought because the original white tank has some holes along the seam. He'd got the side panels too.

Fork stanchions came up good after a polish..

Some books he gave us which will come in very handy!...

A few bikinis..

There's a full set of panels on the rusty cx400 that I could re-paint for the 650. I have some colour schemes in mind. The 400 is complete but he'd stripped many of the parts off and boxed them up. 

The rust is localised to one area and luckily there's enough solid metal on the back that I wont lose any datum points when it comes to repairing it. 

The workshop was getting a bit 'bikey'....

So the 650 will be left alone until I clear out the other bikes. Starting with the 400 which I preceded to strip right down. But before removing the engine/forks/wheels I had to get these pics for future brain storming. Its really easy to see why these bikes, especially the single shock prolink models are so popular for customising. Such a neat clean powertrain setup, especially with the shaft drive.

The 400 was stripped bare, parts given a quick clean as I went, then labelled and boxed up. We now had so many boxed up bike parts scattered about, along with many tanks etc that new storage was needed. So we bought some timber and built shelves into the beach bike/lawnmower shed...

That original cx500 was robbed of a few more parts and I'll now pass it on to whoever might need it. 

So now I'm working at stripping the 400 engine down. I need the camshaft for the 500 engine and there's other bits that will be saved as spares. 

It appears to be in good condition inside..

I've made a few tools as I needed them plus Graham had brought around a clutch lock ring tool when he visited for coffee. 

Once I have finished stripping and boxing the 400 engine I'll get started on the 650 repairs.  What I do know so far is that the water pump impeller splines have seen better days...

Here's a good 500 impeller for comparison..

I can't just simply swap in a 500 impeller because the 650 unit is taller to move more water..

Sadly replacements are hard to come by. Before I commit to buying one the the beautifully machined alloy jobs available from Ralf in Germany I'll have a go at a repair I have in mind.  

I have yet to check the state of the camshaft but Graham had told me he thinks the thread is iffy. Again, I have some ideas about fixing that if needed.  Its all part of the fun and I'll certainly post up how I get on, better or worse.