Old School Honda Engineers - WTF!

[R6_kid]

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. :no:

[slofox]

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

[boman]

It has spark plugs!!!???


:no:

[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. :o

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 :2guns:)

[NodMan]

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.

[Eurodave]

On the up side tho, my boys '88 VTR250 is now having starter clutch issues & I seem to remember that my old '76 CB360 from 33 odd years ago had exactly the same symptoms & so Ive just discovered that the little rollers needed ARE EXACTLY THE SAME ,PART NUMBER & ALL !!!!!
Who would have thought???:wari:

[Motu]

Pretty big call. There are many an old Suzuki GS about, that have never had a spanner on the motor.

There are always exceptions,but there are more airheads that have done big mileages without much work on them than any other machine - mind you,they made them for over 25 years,so that stacks it on their side considerably.

However,the discussion is about ease of maintenance,and the airhead is outstanding in that department.

The XLV750 was designed to compete against the R80GS in Paris/Dakar type events,and key items were very easy to access for the very short maintenance period allowed at the end of day - airfilter on top of tank,quarter turn to remove,spin on oil filter on top of engine,hydraulic tappets,shaft drive.Anything else on the bike was almost impossible to get at without pulling 5 more things off.

[Drew]

The XLV750 was designed to compete against the R80GS in Paris/Dakar type events,and key items were very easy to access for the very short maintenance period allowed at the end of day - airfilter on top of tank,quarter turn to remove,spin on oil filter on top of engine,hydraulic tappets,shaft drive.Anything else on the bike was almost impossible to get at without pulling 5 more things off.
Better than the Cagiva Elephant then. 750ss motor, with really little gaps to get at the carbs, which should have been totally encased in something, the way they fill up with water.

[Bonez]

Snip.Just change the oil/filter, drain the carbs and go for a decent ride..................

Failing that just give it to me.

[Motu]

Better than the Cagiva Elephant then. 750ss motor, with really little gaps to get at the carbs,

I could get the carbs out of the XLV750 in 20 minutes (they were inside the top frame tube) - but it was still a nasty job.I can dismantle the carbs on the airhead without even taking them off.I can fit new diaphrams in 5 minutes tops.

[Squiggles]

OEM toolkits.

[R1madness]

ohhh cb650LC blue with a sikver flash with red pinstripe. Fond memories. I had 1 back in hte late 80s and it took me many miles. must see if i can find a pic to post from then...

[Swoop]

The spark plugs are 18mm nut (or 1/2 inch apparently)
Could be part of your problem... 18mm isn't a 1/2".

[vifferman]

An airhead BMW will outlast any Japanese bike of the era,with less maintenance .
Oh - I wasn't talking about reliability - although Hondas generally are reliable (camchains notwithstanding). I was referring to the Japanese planned obsolescence, where vehicles are (or used to be?) scrapped after 5 years, unless many parts were replaced with new ones.


So you havent had the carbs off yet???
On the VFR750, yes. No carbs on the 800. The fact you've two sets angled in towards each other works against you getting them off, but the manifold rubbers are surprisingly elastic (except maybe old hardened ones.)


On the up side tho, my boys '88 VTR250 is now having starter clutch issues & I seem to remember that my old '76 CB360 from 33 odd years ago had exactly the same symptoms & so Ive just discovered that the little rollers needed ARE EXACTLY THE SAME ,PART NUMBER & ALL !!!!!
Who would have thought???:wari:
There's a surprising (and pleasing) re-use of parts from Mr Honda's parts bin. Just some annoying little differences, like the mirrors are often the same, but the stalks have slight variations in geometry. Most of the front indicator lenses (apart from VFR750s and 800s) from the early 80s right through to today are identical, with variations in stalk lengths (not important). Many disks are interchangeable, which helped me when I owned my VF500. The first wrecker said, "No - I don't got none, and you'll never find any!" The second knew his bikes, and went "Hmmmmmmm..... I think the ones from the NS250 fit.." and so they did (just drilled rather than solid). My VFR has two different front disks, but I haven't worked out whether the RH one is aftermarket, or off a Fireblade or CBR600.

And yes, Mr Motu, older (or old-fashioned) bikes were often easier to work on. My first bike (CB175) required only the OEM toolkit, a set of feeler gauges, and a cigarette paper (for the points) to work on. Everything was easily accessible and simple. My VFR800 takes 20 minutes to change an instrument bulb (although chain adjustment is a doddle).

[jonbuoy]

The only way I can get mine out is with the original plug spanner in the toolkit. Carbs and airbox were a prick until I got new rubbers that were actually rubber - old ones had turned into plastic with all the heat cycles and petrol fumes.

[Brian d marge]

Royal Enfield Bullet

All done in 1937 with a pen paper and a slide rule, Now here in the future with all my stress analysis programs, computers

Not an ounce of fat on any of the parts I look at, EVERY time I analyse a part,,,it always comes back ,,,,JUST,,

as in not over engineered, but on the money , for example, just finished looking at the cylinder barrel

for the 350 the was a margin of error for heat removal, but for the 500 they reduced the CR down to 6.5 to 1 for a reason

50 years later Joe backyard slaps high comp pistons in his Enfield and then chuggs around in fourth , only to find it seizes, wonder why ?

The more I look into these engines, the more I am impressed by these old time Engineers

Theoretically .... all things being perfect, the numbers say 53 hp from one of these engines !!! ( yeah right , I'm struggling for 18 Bhp )

But so easy to work on !!!

Stephen

[R6_kid]

Could be part of your problem... 18mm isn't a 1/2".

Yeh, i sorta noticed that myself. That's what the picture on the packet says though! I took the plug down to repco because I didn't have any long sockets that would fit it.

[Bonez]

Try changing the air filter on a eary Hinkley fours or triples ;). http://www.webbikeworld.com/tbird/air-filter/

[YellowDog]

It has spark plugs!!!???


:no:
Diesels don't use spark plugs - Silly :)

I think they just want to make it impossible to maintain yourself in order to support their dealer network.