Author Topic: Keep telling yourself - a restored 750 K2 is an investment (Read 38538 times)

HondaMan · « **Reply #125 on:** January 01, 2009, 08:56:33 PM »

The one on the cam cover exits to the swingarm's holding clip, and goes down below the arm pivot, to atmosphere. The one on the back of the engine goes to the top of the separator, if yours has one. K2 prior to about SN 1005000 had only one vent tube on the oil tank, like K0-K1, and excess pressure vented through the spring-relief-valve in the cap (which always mists the tank under the side cover $:-\$ ). But, some K0-K1-K2 DID have a 2-hole oil separator in the back of the tank, and the lower tube from that vented to atmosphere. None of them go to the airbox.

However....if you would like to run at high speeds for extended periods with a bit more power on tap (does Britain have room for this?), you can make a pair of 3/16" holes just below the airbox seam, between carbs 2&3, and run THEIR vent tubes into the airbox. This will raise the running float levels a little in the carbs and increase torque and responsiveness when in high gear at speeds around 60 MPH and above.

the-chauffeur · « **Reply #126 on:** January 02, 2009, 11:13:06 AM »

Cool. That answers that question.

In the meantime . . . awww crap. I've spent the last couple of days looking up parts information pending arrival of the 450, and I've found something that's worried me to do with the age of the bike (the 450, that is). To give you a bit of background, bikes manufactured before 1st April 1973 qualify for historic status in the UK and as such, are exempt from road tax - this is one of the reasons that I was attracted to the 450 (which was advertised as a '72); the other was that it matched my '750, which is also a '72. And yes, I checked with the dealer when I spoke to him on the phone, who said he had a dating certificate showing the manufacture date as 1972 - although admittedly I didn't push him quite as hard as I could have done.

Anyways, in the course of my investigations, I've come across several pictures of models from '72/'73 and the associated colour schemes. Long story short (again), it looks to me as though the bike I've bought is a '73 spec model - the colour matches the K6 Brier Brown Metallic (http://www.spookytoms.com/CB750-PaintColors.html). Unfortunately, the bike is now in transit, so it's not even as though I can find out exactly what the frame number is.

Question is, what have I ended up with - and are there instances where the following years' spec bikes were put on sale in the previous year (for instance, K4's being sold in '72 instead of '73)? I guess the tank and panels could have been swapped, but it seems very unlikely . . .

I'm praying (hard) that it really is a '72, but like I said, awwww crap.

the-chauffeur · « **Reply #127 on:** January 02, 2009, 05:59:20 PM »

's alright folks. I think I've found my answer.

Just set me straight - date of manufacture often doesn't have too much bearing on date of first registration (and hence styling beyond frame and engine), right? I've seen one or two posts here and there that confirm my theory that K5 styling doesn't necessarily mean the bike was manufactured in the year that K5's were s'posed to go on sale.

I know, I know - stop worrying about it. There's nothing much I can do 'til I see the bike in all its, ahem, glory. I'll just go away again for a bit . . .

HondaMan · « **Reply #128 on:** January 02, 2009, 07:10:51 PM »

The CB450's sales were slumping in 1971/2/3 because of the 750 and the 500, but the CL450 was selling OK. Dealers were getting them retitled as current year, then swapping the tanks and side covers: Honda would do it for a small fee, if you were willing to keep the old parts as ones to sell as NOS parts from your inventory. It was common practice to spend December and January doing this in the shop with the leftover Honda bikes. Some CB450s and CB350s became the next year's CL models by swapping tanks, seats, front wheels (1" larger wheel on CL) and in the 350, grab rails on the 1973/74 models (I think). If the customer didn't track down the frame ID, it worked out fine. I only remember one customer making a stink about it, so they dropped the price $100 (on a $799 bike, that was significant savings!).

It was because of this stuff that I came to learn the bikes by their "K" value and "half-year K" values. The 350/450/750 all went through "1/2 K" models until I got out of the game. Years later, I learned to 'see' how the new parts were being introduced in production to lessen Honda's costs, not really for changing the "K" model. Mostly, the "K" changes were paint and decal changes, while the engines and chasses, by the end of one year, looked identical to the new ones, like a steady progression. That's one of the reasons the 1971-1975 bikes confuse the typical young whippersnapper behind the parts counters!

the-chauffeur · « **Reply #129 on:** January 04, 2009, 12:51:02 PM »

Cunning ruse by Honda, although I very much doubt they were alone . . . and it leaves me with another quandary. If the 450 turns out to be a K4 from a numbers perspective, should I aim to put it back together as a K4 (given that the changes were relatively minor/cosmetic)?

And back to the '750. Am I right in thinking that the inner cylinders run hotter than the outers - and if so, can the temperature be regulated (relatively speaking) by changing the jetting of the middle carbs?

Your suggestions please . . .

Neil

HondaMan · « **Reply #130 on:** January 04, 2009, 08:04:57 PM »

Quote from: the-chauffeur on January 04, 2009, 12:51:02 PM

Cunning ruse by Honda, although I very much doubt they were alone . . . and it leaves me with another quandary. If the 450 turns out to be a K4 from a numbers perspective, should I aim to put it back together as a K4 (given that the changes were relatively minor/cosmetic)?

And back to the '750. Am I right in thinking that the inner cylinders run hotter than the outers - and if so, can the temperature be regulated (relatively speaking) by changing the jetting of the middle carbs?

Your suggestions please . . .

On the 750: don't worry about the heating. The center cams and spark timing are subtly off to solve the problem already on K0-K1, then straightened out again on K2-later bikes. When Vetter Fairing Company did their windtunnel testing on their famous (but short-lived) Phantom full-length fairing, which had a 31" wide hole in front of the engine, they found that by heating up the outside two cylinders, the engine ran smoother. My friend Jim Chamberlain had the K0 they used for the test (Craig Vetter and he were old friends already by then), and he rode 165,000 miles with that fairing and the K0 over 5 years' time, with one teardown at 112,000 to bore to first oversize on the cylinders.

My own K2 (130,000 miles) had had the Vetter lowers on it almost all the way until 1999, when I took them off and put them in the attic for a while. They are back on it now, to stay, again. I even rode it through Arizona (114 degrees), in city traffic in Mesa and Phoenix, with no ill effects other than the carbs boiling the fuel. The engine never whimpered.

Do take a look at the flash in the casting, between the cylinders, though. I have seen some cast all the way shut with flash! A long, small round file will clean them right out.

the-chauffeur · « **Reply #131 on:** January 05, 2009, 02:14:19 PM »

They think of everything, these clever Honda people, don't they? I'm trying to remember what prompted the question now - although I think it may have been an article I read recently about Kawasaki triples where the centre cylinder ran considerably hotter than the outers. But that's good to know. Can't thank you enough for the info HM - it's not just the detail that makes your posts so informative; like most things, it's the background that adds that extra dimension.

News (of a sort) on the 450. Having booked the collection of the bike in for Wednesday last week, I got a strange e-mail today to say that the delivery firm could pick it up later this week if it still needed doing, and deliver it shortly afterwards, and for considerably more than they had originally quoted. I'm annoyed, frustrated and mystified in equal measure; it turns out the idiot I spoke to who said they would pick the bike up didn't pass on the message, or take down the order, or (seemingly) any other remotely useful information. Quite why neither the delivery service nor the dealer thought to call me and let me know what was going last week is beyond me. So wasting more holiday time, I've decided to hire a van and do the job myself on Friday.

Jesus - this bike business isn't s'posed to be this hard, is it? I just hope it's all worth it in the end.

the-chauffeur · « **Reply #132 on:** January 13, 2009, 02:02:58 PM »

Hooray! The CB450 is now in the garage. I won't bore everyone with the story of how it got there, suffice it to say it - seemingly like every other aspect of my builds - wasn't a straightforward exercise.

Tried to get it started over the weekend, but it didn't want to play. It coughed a whole lot, and tried really hard to get going, but it wasn't having any of it. Couldn't work out what the problem was (with a bike that's been standing this long I guess it could be one of any number of things) so I worked my way round the most obvious things. Cleaned up the air filters, checked the sparks (yup), fuel lines fine and good compression. Having decided that the most likely problem was something to do with the carbs, I stripped 'em down and cleaned 'em up, but it didn't really seem to help much.

So I thought I'd check the points. Which turned out not to be such a good idea, principally because I've still yet to find an easy-to-follow guide to setting the points on the 450. I've tried reading the manual, but given that it was written in the late sixties, it's in the sort of language I find hard to comprehend. About the one thing I have managed to glean is that only one of the points is variable; you need to set one or the other and then move the backplate (or something) to set the other. But I really can't get my head round it, so if anyone can direct me to a better guide/explanation, I'd be hugely grateful.

But never one to let a little thing like points to get in the way, I had another go having juiced up the battery. And after much coughing, the bike roared into life. Yay. Admittedly there seems to be more power from the right side than the left, but I didn't get the chance to work out why before smoking up the garage. I'm just glad it's running. And now the really tricky stuff starts - getting it on the road and registered. I'm going to leave any major cosmetic work until I've got all the paperwork sorted out, 'cos apparently registering the bike can be enough of a nightmare to really ruin my day. One point of interest (if this kinda thing interests you) - the frame and engine numbers start CB450E-600; according to the dating certificate, it was manufactured in 1972 - despite being dressed as a K5.

No news on the 750 just yet - I haven't bothered contacting the shop doing the work on the engine. But after having seen a post about how to extract the engine with a hoist, I've wired up a winch in the garage. Should make putting it back into the bike a whole lot easier.

Photos of the 450 progress to follow.

HondaMan · « **Reply #133 on:** January 13, 2009, 06:22:46 PM »

Typically, setting the points gap to .014" on each side gets it REAL close, at least with TEC or Hitachi or Denso points. Then you can just slightly twist the backing plate to line up the first timing marks, and the gap changes slightly on the other. You can then, if a purist, "split the difference" between then and untwist the backing plate to in-between, for best performance.
If the points are of another brand, all bets are off, but look first for parallel faces on the contacts before installing new ones: bend the ground arm to make parallel contact if not. Some of the 3rd-party, non-OEM points have extra-long lifter arms on them, forcing you into a .016" or larger gap to get the timing marks to line up: not good for the dwell on those bikes. Contact me for further help if that happens to yours. The SOHC4 bikes are seeing some of this, too, on those $5 point sets out there from China.

the-chauffeur · « **Reply #134 on:** January 14, 2009, 02:13:27 PM »

Hmmm. Dunno who made the points. Perhaps this'll help . . .

and

The electrical problem turned out to be the fuse. It's not bust in the way fuses conventionally blow; instead I think one of the ends on the inside had come adrift, so no matter how hard I looked, I couldn't see that it was broken. Anyways, that sorted, the bike decided to be a real pig to start. It seems to need an almighty amount of cranking and juice (electrical) to get going, which I'm sure could be a number of things but having given the carbs a good clean, I'm inclined to lay most of the blame on the points.

More photos . . . (with apologies for the cramped conditions; one of the bikes leaves the garage at the weekend, giving me more elbow room)

Can't remember whether I said this before, but probably the politest thing I can say about it is that the bike is complete. Once I get the registration/documents sorted out, I'll be stripping everything down and getting the frame powdercoated. I'm also intending to keep all of the original fasteners but get those that need it rechromed/zinc plated. Pretty straightforward stuff, really. But while I'm on the subject of paint (sort of) what colour should the engine stays be - the plates holding the top and front of the engine in place? As you can see from the pictures, the ones at the top of the engine are so rusty, I can't for the life of me work out what colour I'm looking for . . .

AND - breaking news on the 750 . . .

The garage tell me that the clanking noise was caused by one of the gears having been put back on the spindle back to front. They haven't said whether it was my fault or theirs (remember, I had the engine apart first) but either way, I gather that the bottom end just needs to be re-assmbled and it'll be on its way back to me. Frankly, I could care less who was wrong - all I'm worried about is that it works (which I'm sure it will). As I'm concerned, it's all good.

HondaMan · « **Reply #135 on:** January 14, 2009, 06:11:37 PM »

All the engine mounts are black, like the frame. Yours has poor grounding at the moment, which has led to the electrolysis that's peeled the paint from the upper mount. Check the condition of the engine-to-battery ground cable and mounting bolt for crud buildup.

The points look like they have very small gaps: see if they are black on their faces after the long storage. If the condensors were old, the points tended to burn black, then absorb water, then become very poor at switching high currents: all equals weak spark. If they are black, plan on new ones, and new condensors.

The blue wire is mounted wrong: the connector should be spun around and flipped, so it is mounted with the wire exiting toward you, on the spring side of the points, then running midair, back to the hole. It appears the grommet is gone, hence the tape. When the grommet would rot away, it would allow for those points wires to chafe off their insulation, back where they exit the housing. Then they short and the engone won't run for beans.

Artfrombama · « **Reply #136 on:** January 14, 2009, 06:58:39 PM »

I've found it's more cost effective to replace the entire breaker plate assembly instead of just the points.
(I noticed you're missing the lube felt and the rubbing block on the LH points are worn down)

the-chauffeur · « **Reply #137 on:** January 15, 2009, 01:29:56 PM »

"Poor grounding"? That's a very polite way of putting it.

Thanks for the pointers on the colour - I'll add those to the list of parts to go to the powdercoaters.

I was debating whether to buy a new points plate, but I think your joint comments tell me that it'll be a very worthwhile investment. Very kind, gents.

Back soon . . .

the-chauffeur · « **Reply #138 on:** January 19, 2009, 01:04:31 PM »

I'm sure you guys don't need me to tell you . . . new points + decent grounding = easy starting (kinda). New points made a hell of a difference to the 450. So much so that it only takes one or two jabs on the starter to get it going. Most of the other bits work too, so it shouldn't be too long now before I can get it registered and then stripped completely.

But it's a lot noisier than it should be right now - principally because the bike is missing exhaust gaskets. I'm not quite sure how the exhausts were holding firm before I took them off, but there certainly weren't any gaskets in there anywhere. I have a feeling they were being held on by badly fitting collars, which brings me on to today's questions.

Does this look right to you (specifically the split shields between the pipe and collar):

I can't help thinking the shields shouldn't protrude as far as they do. But maybe I'm wrong. Any thoughts? Should I give some thought to grinding them back so that they don't extend beyond the collars?

And doesn't the engine look a mess under harsh light and close up? So, is some form of pressured steam the best way to clean it without the aggravation of stripping it down to its component parts?

Two other things concern me. The exhausts - they're nigh on impossible to replace, so I might just end up getting stainless repro's made up, 'cos the finish on the Honda's is, erm, woeful. The other thing is the tank decals. Can't find a supplier of 450 K6 tank decals anywhere. But I've got a few leads this end . . .

Artfrombama · « **Reply #139 on:** January 19, 2009, 02:30:31 PM »

I think you have the split collars in backwards

the-chauffeur · « **Reply #140 on:** January 19, 2009, 04:25:20 PM »

Nuts

Thanks Art - you're quite right. Schoolboy error there (one of an increasingly long list). I've just been out and swapped one side round, and it gives a much tighter fit.

But that fitting raises another question - with the split spacers the right way round, the collars don't sit flat against the engine. Even when tightened down, they're at least 5mm away from the head. Is that right?

Thanks (and sorry for wasting time)

Neil

Artfrombama · « **Reply #141 on:** January 19, 2009, 04:35:30 PM »

Quote from: the-chauffeur on January 19, 2009, 04:25:20 PM

Nuts

Thanks Art - you're quite right. Schoolboy error there (one of an increasingly long list). I've just been out and swapped one side round, and it gives a much tighter fit.

But that fitting raises another question - with the split spacers the right way round, the collars don't sit flat against the engine. Even when tightened down, they're at least 5mm away from the head. Is that right?

I believe so, but most on this forum more qualified to answer than I.

Quote

Thanks (and sorry for wasting time)

Neil

Don't apologize, wasting time and internet forums are something I like!

HondaMan · « **Reply #142 on:** January 20, 2009, 04:59:00 AM »

Art has it right.

the-chauffeur · « **Reply #143 on:** January 31, 2009, 04:38:26 PM »

Back again folks.

Most recent news on the 750 is that (yes - I know it's taking an inordinate amount of time) the shop needed to replace the clutch thrust plate which snapped when it was being put back on. Don't ask. All I know is that a new one has now arrived . . .

Back to the 450, and I need some help with the carbs. After sorting out the exhaust collars - thanks Art and HM - and getting the points set right, the bike kinda ran. Sort of. The story so far is that I replaced them (and the condenser) and put in new plugs, which produced some big ol' sparks. Got it started, but it was running very rough, and the idle was/is all over the place.

For the short time it ran, the engine sounded fine so I turned my attention to the carbs and having stripped them and put the component parts (including bodies and steel diaphragms) into an ultrasonic bath, I found that one of the floats had a couple of holes in it. Replaced that, together with 80% of the internals on both carbs (jets, float valve, seat and washers) and generally cleaned up the other bits. Put them back together with new fuel hoses to the tank (and cleaned fuel filter gauze) and back on the bike, and . . . it's still all over the place.

So, here's what I'm left up against:

- The engine will now run (and race through the rev range) with the choke at various levels of open-ness. It'll also respond to throttle movement when the choke is open.
- Close the choke down and the bike dies. Literally. It'll run with the choke closed only if there is some pull on the throttle, but unlike when the choke is open, yanking the throttle wide open doesn't increase the revs. At all.
- The correctly gapped plugs (somewhat unsurprisingly) come out dry but coked up.
- Strangely, neither pilot screw seems to make any difference to the running - they can be either fully in or fully out, but the bike still runs with the choke open and stops when it's closed.
- throttle cable moves freely, but the only way I've managed to get the bike to run is with the cables set so that the throttle stop screws don't reach the stops
- with the choke part way open, small quantities of fuel are expelled out of the rear of the carbs. I thought this would be cured by new float valves and seats, but it seems not.

In an attempt to diagnose some of the troubles, I took the air filters off. What I need to know is whether they need to be fitted before the bike will run properly (I gather some bikes are very picky about running with filters in place)? But what I don't want to do - given their scarcity - is get them covered in fuel.

And obviously I need to know whatever hints and tips you folks have for setting up the carbs from scratch. Right now I'm waiting for a set of extra long feeler gauges to check the valve clearances - 'cos they're about the only other thing I haven't checked yet - but even if the valves were out, I doubt they'd make a huge difference to the carbs ability to breathe.

Help if you can; sympathise if you can't.

Neil

HondaMan · « **Reply #144 on:** January 31, 2009, 09:12:53 PM »

It sounds like the vacuum pistons are not rising as the throttle is opening. This is the one bugaboo of the CV carbs on those bikes.

Here's how they work: the (very) polished edges of the pistons in those carbs literally ride on an air bearing surface, up and down inside those covers the ones on top of the carbs). They must be as clean as a hospital operating room around the piston edges and the inside of the covers, free of pitting that raises any bumps inward, or the pistons will stick and not rise or fall. Now, when the throttle butterfly snaps open suddenly, the piston is low, yielding a rich mixture so the engine does not stall, as with conventional slide carbs. A split second later, the vacuum on the tiny venturi (side of the bore, downstream of the butterfly) that is on the downstream side of that butterfly starts to pull up on the pistons, and they rise in synch with the engine's increasing RPM. When the throttle is snapped shut, the piston hangs for a while at the former position, then starts back down, so if the throttle is immediately snapped open again, it's ready to rock-n-roll. This was the genius of the 450 Twin, and the reason it ran so well with big carbs.

Enter time and corrosion from non-use....

The insides of the covers (called the "bores") can get irregular, corroded, or rough surfaces. The clearance between the edge of the piston and the bore is .0008" to .0012", so it takes almost nothing to make the pistons stick. In addition, the vacuum port that reaches from downstream of the butterfly valve upward into the top of the cover can get blocked with corrosion (a white powder) and debris. Also, if the gasket on the bottom of the cover, where it seals against the carb body, is not perfectly sealed, or was sealed with goo (i.e., Permatex or the like) and it oozed into the tiny passages, then the pistons will not lift.

Also, if the covers got swapped from one carb to the other, or installed 180 degrees away from the original positions, the pistons will stick. They were matched, piston-to-bore, at the factory when the carbs were built. Most common error: swapped covers when both carbs were disassembled at once, then reassembled at random.

The result of stuck pistons: when the throttle is opened, the momentary richness lets the engine rev, then it reaches a point where it will not rev further, and tends to hang there when the throttle is released. After that, the pistons will jerk themselves upward during engine deceleration, leaving them sitting too high in the bore, and the engine runs lean at idle and dies. Pretty common on 450s with no air filters: the dirt would either stick the pistons in place or wear cuts and grooves on the covers, then the trouble would start.

In short: see if those pistons move with just a VERY light lift of the finger by reaching in the air horn and lifting them: if not, take them apart and find out why not.

the-chauffeur · « **Reply #145 on:** February 01, 2009, 05:50:17 AM »

There's a fine line between despair and delight . . .

HM - you were, as always, right. A little test - taking the caps off the carbs with the pistons inside them, leaving them upside down on a workbench for half an hour and then trying to extract the pistons by lifting them by needle alone told me all I needed to know. One piston slid out with very little friction. The other didn't - in fact, the friction was so great that I was able to lift both the piston and lid together. That's not so good - and is exactly what you'd described above.

On your advice I swapped the pistons between lids and things improved considerably. Both slide in and out with varying degrees of (much reduced) friction, although rotating them in the new lids had little effect. But on closer examination - bearing in mind your cleanliness comments - I found this:

Normally, dark marks like this would simply be banished by the use of wire brushes/wheels and or polishing kit, but again, bearing in mind the clearances we're dealing with, I think it best to approach the removal of this junk very cautiously. So far, the bits in the picture have been subjected to little more than an ultrasonic bath of engine degreaser and a quick introduction to a sisal wheel. But as you can see, they're still marked.

So can I ask for recommendations for slightly more aggressive cleaning/removal methods that won't bugger up the tolerances (or will have minimum effect)? I've got access to a fair range of tools and fluids at my disposal - including 2000 grit wet and dry, solvents and so on - so suggest away.

Neil

HondaMan · « **Reply #146 on:** February 02, 2009, 07:25:49 PM »

I think you're on the right track with the light grits, like 800/1000/2000 for the cover. The piston will probably like the 1000 to at least knock the tops off of the corroded, raised edges of the bad spots, ditto on the covers. Those should recover pretty well, just go gently because the metals are surprisingly soft. Try wrapping a turn or so of the 800 grit around a steel rod to lightly pass over those rough spots to see which part is raised and which part is sunken: you're going after the raised part and don't really care about the sunken bits. They don't have to be mirror-finished in the cover to work well, but the edges of those pistons should be nice and shiny smooth. The gasoline fumes build up in those tiny grooves around the edge, and oil the pistons. Gas is approximately 3w oil, so it lubes pretty well here.

Those aren't too bad, compared to some I've fixed...

the-chauffeur · « **Reply #147 on:** February 03, 2009, 12:37:44 PM »

Well, a combination of the above seemed to do the trick. The pistons now slide up and down with relative ease - and more importantly, rise and fall with the throttle turn. But despite my twiddling and twisting, the idle/running was still all over the place. Cue much head scratching and pulling of plug caps, removal of plugs and pacing round in circles.

Then it dawned on me - compression check <-if you're going to shout at me at this point, please do so quietly->. Quite why I hadn't done this before I don't know, but anyways . . . oh dear. 100psi left; 50psi right. Well, that would explain why the right cylinder wasn't firing with as much ooomph as the left. Even with a squirt of oil, the right wasn't going to record any sort of decent figures. And neither of them are anywhere near the 150psi quoted in the manual. Crap. I'm guessing that there is something seriously wrong with the right cylinder (piston ring or scored barrel maybe) - such a big difference between book figures and actual can't be down to dodgy valve(s)/settings alone, can it?

So my plan of getting the bike running and registered and then stripping it down is going to get turned on its head. Hey, no biggie - ultimately it doesn't really matter which way round I tackle the job(s), but I figure I that if I'm going to have to try to correct all of the issues, I might as well do them all at once.

Time passes . . . five hours to be exact. So the bike is now down to its component parts. The frame is in the back of the car to go to the powdercoaters; chrome bits are all in boxes; the exhaust is also in the car so I can find out how much a stainless steel replacement will cost to make; and the engine is on the workbench. Side covers are off, and I'll start work on removing the cylinder head next. If this all sounds a little premature, not to worry. I've been umm-ing and aahhh-ing over starting the teardown for a while, so the bike kinda made the decision for me. And this way I can check everything out of the frame and maybe spring a few surprises.

Pity we don't have the same chrome-plating services you guys in the US have access to. Ours are nowhere near as good - and the ones we do have are few and far between.

HondaMan · « **Reply #148 on:** February 03, 2009, 06:46:44 PM »

You'll probably find a crudded-up or slightly burned valve. It's rare that the bores are torn up, unless some foreign objects got inside somehow. Only the exhaust valves and seats are stellite on the 450, so the intake seats sometimes take a beating if not stored properly.

Of course, there's also the long storage and cylinder rust possibilities, I guess.

Did the valve lash come out OK? If you have one that's more than .006" loose and can't be reduced with the lifter adjusters, that's probably the one...

the-chauffeur · « **Reply #149 on:** February 04, 2009, 12:45:50 PM »

I must confess, I hadn't measured valve lash - I kinda just dived straight in and started pulling things apart.

It's not a very pretty sight. Not appallingly bad or anything, but not pretty. Took the head off and found the valves looking, well, cruddy . . .

,

So yeah, I think it's safe to say there's some work needs doing there. Then I pulled off the barrels. Spot the odd one out:

Turns out both cylinders had the top piston ring in two pieces. I assume that's part of the problem - and not intentionally separated rings; at least, the fiche shows one conventional top ring for each cylinder. The cylinder walls themselves look pretty much unscathed, but in the process of removing the pistons, I managed to fire one of the gudgeon pin retaining clips across the garage and into oblivion. Fortunately that's a cheap and easy bit to replace - as are the piston rings - but look what I found on fleaBay . . . . Yup, they're mine now. Hey, if I'm gonna do it, I might as well make a decent job of it.

The head is now in bits, and the camshafts came out without putting up too much of a fight. Next question - am I right in thinking these things have got some useful life left in them:

And now to work out how to get the valves out . . .

News:

Author Topic: Keep telling yourself - a restored 750 K2 is an investment (Read 38538 times)