Project: NTV600

I’ve bought a 1988 V twin, shaft drive, naked Honda as my next challenge.

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The camera flatters it, it’s a bit rusty and the paint isn’t as lovely as the on the pictures.

Apparently it was stood for about 14 years, someone put it back on the road last year, and it’s blown up.

The guy selling it said he thinks it’s dropped a valve into the barrel, whilst running. (Which will have done all kinds of damage to the front pot.)

Here is the one of the front spark plugs. I’m inclined to agree.


After a frustrating day on Nathan’s bike’s electrics I made a start on this today.

The manual says you can strip the pot with the engine in frame, which is a bonus, but it’s still a huge faff.

Just to move it into the shed (I’ve relegated Nath’s to outside, under plastic) I had to remove the seat, tank, side covers, air filter box, (must get a new air filter) take the radiator covers off, disconnect the radiator hoses from the engine, then remove the radiator.

Once I’d done that I was free to move the bike into the shed and start work.

I had to disconnect the carbs and move them out of the way, take off the cylinder head cover, then found out I had to remove the radiator cap assembly just so I could swing the cover out. The other spark plug was wedged in tight. I think it was embedded in the piston. I got it out in the end.

And I’m here.

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To be honest, that all looks deceptively pristine.

I’ll take the cylinder head off tomorrow. Then it’s all going downhill.

Fun times.


I gave it a go. There’s quite a bit to it, not just unbolt the head and pull it off.

I drained the coolant, then the oil. This came out in the oil.


It’s not large, but it looks like the stuff of which the engine is made. And nothing metal should be in the oil, especially not that size.  Oh dear.

I removed the covers to the crank bolt thing and the inspection cover. In the book it says turn the crank nut anti clockwise until the Top Dead Centre (TDC) mark on the rotor aligns with a notch in the inspection hole.

I turned it around a bit, but you’ve only got about 3/4 of a revolution then it jams solid.  Oh dear, oh dear.

In that space I managed to find the timing lines, so that was good, but the next thing was to turn the crank around until you can take out two bolts. Except I can’t get a full revolution of the crank. I got one 10mm bolt out (really stuck) but it’s really, really hard to get at the other one. I can’t revolve it far enough to get a socket on it, to apply my breaker bar or impact driver, to stun it loose. All I could get on was a small 10mm spanner and that was rounding the bolt head. I was very frustrated. It’s simply impossible to access because I can’t revolve it and the frame is in the way.

I was despairing. Beaten at the first hurdle by a 10mm bolt, and a dead engine with metal in it.

I gave up.  As I was putting my tools away I realised the solution was in the statement. I can’t access the bolt because the frame is in the way, so remove the engine from the frame.

I said to Wendy, “if there’s metal in the works I’ll be getting a replacement engine anyway.  Either that or strip it right down…”

As I was saying it I realised I’d lost sight of the goal. I was rushing to get the bike back on the road and ride it. That’s not what this is about. I want to practice and acquire mechanic skills. Stripping the engine completely is perfect for me.

I’m refocusing.

It takes as long as it takes. Better to have a year long project to keep me busy than throw another engine in it and learn nothing.

Start again tomorrow.


Another bout of plague weakness has been slowing me down, but over three sessions I’ve managed to strip the assorted parts off the engine to drop it. It has been a pain, but tonight it finally came out.

Then I was stuck. The frame comes down in two arms, which, if the engine was on the ground, would give you just enough room to wriggle it through the V of the engine. As it was on my trolley jack it wouldn’t fit. In the end I had to get Wendy to move the trolley jack as I lifted the frame off the engine. Well, she tried. The inch she moved it was, oddly, enough. Bless her.

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So, here we are. I’ve moved the frame out of the shed and covered it in plastic. I’ll pop the rocker box cover back on and give the engine a damn good clean with paraffin. (Don’t know why paraffin, but that’s what it says in the manual) then set about stripping it.

I’ll try jacking it up again tomorrow, see if it’s any easier to lift, but if not I may have to strip it, at least partially, on the jack. It weighs a ton.

See how it goes. If I’m really stuck I can always buy an engine hoist. They’re about £120, but once you’ve got it, it’s there for life.

Another thing I’m thinking about is upgrading my shed. This is a great shed, but just not big enough. With the front wheel wedged in the gap between the bench and tool cabinet (shown above) I still couldn’t shut the shed door fully. And I have to step over the front wheel to work on each side of the bike, or swivel over the bike. Then squat awkwardly to work on each side. I undid the wrong bolt twice tonight, because I lost sight of the right one as I stood to get better leverage to break it free.

A new shed is a lot of money and faff but it would make life a lot better, if I’m sticking with this. And there’s the rub. I get mad enthusiasms, then lose interest.

Anyway, progress. Get it cleaned, and stripped. I’m dying to see the devastation under that cylinder head.


The good news is: once I’d raised the jack up fully I could keep my back straight and use my legs for the lift. If you think of Caine moving that cauldron at the beginning of Kung Fu, it was like that but more painful.


Done though.



The bad news is that stuck 10mm bolt was a pure pain. I had to drop the engine just for that, but when I did it was too late, the damage was already done, the bolt was rounded. And, I realised after, it took my 10mm socket with it. The socket has been rounded as well. I’ve had to buy a new one. I spent two days trying to get the bolt out. I couldn’t impact drive it, get a spanner, socket or breaker bar on it, I tried to cut a groove in the bolt head and use the impact driver to shock it loose. Nothing. I bought some toughened drill bits and and extractor kit (left handed thread, so as it bites and turns it screws the bolt out) but after two days of trying to drill it I’d drilled in about 2mm, the extractor couldn’t get a grip. In the end, in desperation I used my angle grinder to grind the bolt head off and yanked the sprocket off. Just to rub salt in the wounds, the remaining bolt came out quite easily with a a pair of mole grips after that.

That was my penultimate ploy. If that hadn’t of worked I had left was to use the angle grinder to saw clean through the cam chain, sprocket and bolt. That would have been awful. For one bolt.

Anyway, with the 10mm out of the way it didn’t take me long to get the head off.

There’s your problem, there mate:

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The valve has indeed fallen into the cylinder. And punched right through the piston.

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And smashed my cylinder head in. Like the piston the cylinder head should be smooth.

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It’s not as easy to see as the piston on that picture, but it is so deeply scored it’s basically scrap metal now.

The valve should look like the black one, top left on the picture above.

Not so much.

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It’s Sunday today, Bank Holiday Monday tomorrow, so I’m probably going to have to wait until Tuesday, but I’m going to ring and price a rebore/ pistons/ rings for both barrels. That would be my best option, at least I know I’ve got a balanced, good as new set of barrels and pistons.

If it’s a complete rip I can get a used barrel and piston, and just get new rings. Not the best option, but should be sufficient.

I’ve ordered a second hand cylinder head off eBay. It’s still got the valves( / valve springs, retainers) in but nothing else. I’ll read up on how to check the valves and such before I rebuild it, but hopefully that will be a bolt-on replacement.

Now I have to strip the engine right down and clean every bit of metal out of it. I was talking to a professional mechanic I follow on Twitter, and he said “and replace the oil pump, etc” I hadn’t thought of that. They’re not dear, 40 odd quid new, but it hadn’t even occurred to me. That would have been a disaster, rebuild it then the pump starts releasing metal fragments or just seizes.