Old School Honda Engineers - WTF!

[R6_kid:Me]

As some people know I currently own a 1985 Honda CB650 'Luxury Custom' which I use as a commuter. As I've been working less than a kilometre up the road the bike has been sitting in the garage for the last few weeks gathering dust. I've done just under 5000km on it since I bought it so figured I'd change the plugs and do an oil/filter change too.

I honestly think that those sushi eating nippon pricks back in the late 70's were thinking 'we make motor fucking stupid design, so you need special tool for spark plug, and little hand and magic wand to take off carburettor'.

The spark plugs are 18mm nut (or 1/2 inch apparently), but every single one has some sort of retarded obstruction making it a mission to take any of them out. Both of the outside plugs (it's and IL4) have 'knuckles' above them, so I hit the spark plug with the grinder to round the top off so that I can actually get the socket back out (or on in the first place) when I'm done doing them up.

One of the middle two plugs has the revcounter drive cable directly above it, which I have removed thinking it would now be straight forward, BUT NO, a standard 18mm socket doesnt even fit down the fucking hole. Back to the grinder to thin the plug socket down... second time around, it goes in with a bit of a wiggle from an awkward angle.

The other middle plug is the only one that is remotely straight forward, but it still has a head bolt sticking out in the way just keep things 'interesting'.

Getting the carbs off, according to the manual 'may require some gentle maneuvering'. Yeah right, you have to BASH the air box out, it's larger than the dimensions of the frame that it sits in. You then have to take off the intermediate airbox - everythin is so tightly packed in that they needed to split the airbox in two. You then remove the the rubber stacks which mount the intermediate airbox to the carbs. Then it's just a matter of getting the cables off and pulling the carbs out. But of course, getting the cables off is anything but straight forward. Once it's all disconnected the carbs come easy.

My 'more complicated' GSXR1000 was straight forward to work on, and was much simpler in my mind.

Is this something people find with all 'old' bikes, or is it universal to Honda motorcycles even through til today?

If I ever meet the guy who designed this bike I'll be seriously considering putting a fork in his eye - lets hope the oil change is straight forward.

[martybabe]

I hear you mate. Slightly off topic, I had a fiat sporty something or other and taking out the plugs was an afternoons job, just the bloody plugs man, a full service could drag into a week and cost me every knuckle I had.

Back on Topic, I think it's just different models our kid, some are easy peasy and some just down right bastards. I take it the troubles you describe are with the petrol tank off, should allow access to most plugs but I'm guessing you already did that eh. No sounds like you've got a stinker, good luck with it mate from a fellow sufferer of mechanical conspiracy's.

[slofox]

I haven't even found the plugs on my bike yet...

[boman]

It has spark plugs!!!???

[Drew]

I haven't even found the plugs on my bike yet...

There's FOUR plugs on your twin, dont miss any.

Wait till ya try taking the air box out of an '87 GSX750. The motor has to come out, no joke!

But seriously, the carbs should come out by pushing the rubber stacks back into the airbox. To put the stacks back, ya gotta piss around a bit though.

[EJK]

I thank Yamaha designers. Well... apart from that mine's got only one spark plug, I can literally walk out there and take the plug out in less than 20 seconds.

And I bet a trained monkey can do it better.

[cheshirecat]

I had a CB160 once which was a delight to work on - only 10mm 12mm and 14.
The manual advised re bleeding something was to "peep through the hole and hit the cripple"

[Brian d marge]

I worked with the guy who had a few things to do with the CBX, the XL motor sport and some others

We called him Teapot ( as in as mad as a march hare from alice through the looking glass )

Hope that helps

Stephen

[vifferman]

Hmmmmm.... I think some of it is just restrictions with the amount of real estate available, but some of it must be because it's unlikely some of the parts will ever see a spanner or screwdriver in Japan before the bike's scrapped.
My VFR isn't too bad to work on, once you've worked out how the plastics are attached, and despite the black hole that lurks inside the engine V, waiting to gobble wayward screws, nuts, tools, etc. I changed the spockling ploogz recentlyish: the rear ones required removing the seat, undoing the rear tank bolts, and lifting it up. the sparkplug wrench that comes with the toolkit is great: perfectly designed to fit down the wells, with a rubber insert to hold onto the plugs. A 10mm socket and ratchet on the handle make things easy.
The front ones require undoing two bolts on the oil cooler, which pivots down.

The only work I've done recently which had me cursing was fitting the rear shock. Despite the detailed and well-illustrated destructions, the blardy thing would not fit in. I eventually worked out it was IMPOSSIBLE to fit it in with the top mount attached, despite a picture showing it happening. They had done all their testing etc. on a 98 model. Unfortunately, the 2000-2001 model has a catalytic coverter which is more fatterer than the collector on the 98-99 models. Grrrrr!! and all that. Pounded on the top of the cat to teach it a lesson for nothing.

The VTR1000 was a bugger to get at the front carb's manifold vacuum connector, as was the manual camchain adjuster I fitted. And the screws on the TPS. Otherwise, it was piece of piss to work on.

How about this for dumb: I helped another KBer with trying to balance his VTR250's carbs (no - that WASN'T the dumb thing). The vacuum spigot thingos line up perfectly with the frame tubes. Some Kiwi in-jin-new-itty fixed that (No, I didn't cut holes in the frame, but it was tempting...

[Pedrostt500]

Yep owned one of those CB 650 Customs once, great heavy slug of a thing,
From memory I used an 18mm tube socket on the plugs, with a swivel extension, the plugs wern't hard to do with the tank off, as for the carbs I didnt think the air box was that bad to remove compared to some bikes of the era, just remember do not get carb cleaner onto the upper vacume diaphrams on those carbs as it will break down the rubber, use warm water and dish washing liquid, and dry well.

[AllanB]

It's a honda - leave it alone!

Actually often the best thing is the factory plug spanner - very thin and made to slot down that tight little hole.

Or a proper plug spanner - I've several of these due to different vehicles.

[Motu]

but some of it must be because it's unlikely some of the parts will ever see a spanner or screwdriver in Japan before the bike's scrapped.

An airhead BMW will outlast any Japanese bike of the era,with less maintenance - and yet everything,carbs,plugs and tappets especially would be easier to access than any bike I've ever worked on before.

[ZK-Awesome]

If I ever meet the guy who designed this bike I'll be seriously considering putting a fork in his eye

While you're there, give the guy that decided to put twin mufflers on my GB250 as stock a good eye-forking as well (it's right in the way for all the rear end & chain jobs )

[NodMan:Me]

Hmmmmm.... I think some of it is just restrictions with the amount of real estate available, but some of it must be because it's unlikely some of the parts will ever see a spanner or screwdriver in Japan before the bike's scrapped.
My VFR isn't too bad to work on,

So you havent had the carbs off yet??? one of the worst sets Ive had to remove (several times)....but your dead right about the lack of room available on more modern bikes.... gimme a good old Z1 to play with anyday

[Drew]

An airhead BMW will outlast any Japanese bike of the era,with less maintenance - and yet everything,carbs,plugs and tappets especially would be easier to access than any bike I've ever worked on before.

Pretty big call. There are many an old Suzuki GS about, that have never had a spanner on the motor. But with the pistons not in a postition to hit the ground, your maintanance argument stacks up.