Topic: OK, almost done. Need some input!

[Nurse Julie]

Have you mentioned that the UK model ranges, specs and parts fitted are different for both the 500 and 550?

[HondaMan]

Have you mentioned that the UK model ranges, specs and parts fitted are different for both the 500 and 550?

I'm a little "short" in that area (other than mentioning it) due to lack of hands-on experience with the Euro bikes (other than 1 of them). It's hard to learn something you've never seen? 

[Nurse Julie]

Have you mentioned that the UK model ranges, specs and parts fitted are different for both the 500 and 550?

I'm a little "short" in that area (other than mentioning it) due to lack of hands-on experience with the Euro bikes (other than 1 of them). It's hard to learn something you've never seen? 

I agree Mark. Maybe put a mention in the front of the book that only USA models / specs etc are covered and the rest of the world has different models and varients. It's very confusing for many owners here in UK (and other countries I expect) when, as an example, the UK had the 500K1 up until late 1975 and we didn't get any 550 model at all until the F1 in 1976 and in USA the model range was totally different. Plus, in USA bike models are refered to by their model year, in UK they are only know by the actual model, ie, 500K0,500K1,550F1 and F2 and 550K3, that is entire model range for 500/550 from 1971-1978.

[HondaMan]

Yeah, they sure have gone to the mat for the SOHC4 riders at CMSNL! I've bought many parts from them in 'thanks' and also because, in sandcast 750, they were one who actually found some of the real NOS parts. I have a whole collection of their little winking mechanic-on-a-keychain they send with each order.

Lately a bunch of riders have contacted me from France with SOHC4 questions, which has been historically silent (to me) on the topic. I think they might be joining in the party, now? There are 6 Transistor Ignitions on 750s there now, a recent development.

Thanks for the tip on how to bring up the different models, too: I didn't know that! They have some good programmers doing their website, too. And according to their online parts listings, I bought the last existing groove final-drive bearing for the mid-stage 750 sandcasts when I did that engine a year or so ago. That one hasn't repopulated again.

Did you get a better mainjet for your 500? that #78 had to be limiting your top speed...

Yeah, I like CMSNL's consistency. When I used their function to see which other Honda models had such and such part, I noticed that CMSNL will not list other models, when the part involved is a repro, an 'alternative part' (indicated by a P added to the partnumber). Very prudent of them. I once had the guy who started CMSNL, on the phone. It was in the late 80s when he was still doing his then limited business from the attic.
For some reason our CB500 models don't need a bigger main jet than the #78 one. The Germans and I have experimented with running #100 main jets and the air duct lifted. It brought nothing but extra intake noise. All tests in continental Europe showed that ours delivered the CB500s full potential (top speed 179km/h (112mph)). You may check the graph below of my run on the Dyno. I had 40,6 HP on the rear wheel and managed a top speed of 185 km/h, which is theoretical ofcourse, as you will never reach that in riding wind.
I never solved why we had the #78 jets. Actually when I entered this forum for the first time, it was to find out if anyone knew more. Some say, it's about a better quality gasoline, but I don't know. On the other hand, it would at least compensate for paying the highest prices in the world  . Some others suggested the air duct* allows a better flow than a gauze. I dont know.
* The air duct was there to meet German's demand on intake noise. (see their official TÜV report below)

I think you've tapped on the shoulder of the "secret" about the mainjets. It's about the airflow to and thru the carbs, and where the carbs actually stop working. The German intake change (which interestingly never made it to USA bikes) provided the same type of still-air situation that roadrace fairings and (on the street) the Vetter Lowers with the Windjammer fairing created - this latter feature being Craig Vetter's dream of bringing roadrace-worthy fairing performance to average bikes.

I'll give you a hint, which I first "picked up on" from having seen the original Phantom fairings for the 750 from Craig, and how the Vetter with Lowers [reportedly] came about: during the initial testing of the Vetter Phantom fairing in the college's automotive wind tunnel (Illinois' Champagne-Urbana campus, 1969) that was preconceived as being done to test the [lack of] cooling of the 2 outer cylinders of the 750 engine, the accidental discovery of increased horsepower showed up on the dyno after the fairing was fitted (and the bike wasn't actually moving, of course, chained down to the test drums). After the thermal testing was done, the fairing-off, fairing-on test was [said to be] repeated, and the HP increase (about 2 HP above 90 MPH, dyno max speed) was found again.

What happened was: the wind tunnel's maximum airspeed speed was 90 MPH [another reported number, I have no equipment list for it], which was used in full, and the dead-air space created in between the engine and the front of the battery box from the fairing's width created a high-pressure zone right where the airbox intakes breathe. So, it got some free turbocharging because STILL air is always at higher pressure than MOVING air. It was said that became the day when Craig abandoned the then-new Phantom fairing approach because he wanted that effect in full. This led to the upper half coming out first (the Windjammer) and after lots and lots of research (and obtaining lots of touring bikes to get the shapes) the Lowers came out in 1972 as an accessory to the specially-shaped lower portion of the Windjammer fairing. Their publicly-conceived purpose of keeping one's legs dry in the rain and warm in the cold air riding days overshadowed Craig's purpose: that of increasing the bike's performance for merely bolting on a fairing (which I can attest to, for over 50 years).

Still now, as I type this, I remember how I felt when I bolted the Lowers on mine in 1973: I had by then ridden 15k miles with the Vetter and knew it well: the Lowers ADDED almost 10 MPH to my top speed immediately, and over that summer (of gasoline shortages) I learned it also added 2 MPG to my fuel economy at 70+ MPH. The only reason: it increased the air pressure at the airbox. Then the 55 MPH business took over in the USA, and that whole prospective experience was lost.

Honda made it official (IMHO) when injection-molding technology improved to where they could make the 1975 750F0 airbox with the backward-facing inlet vent (without warping that long, thin edge): the 750F0 with the 087 series "smog" carbs worked WAY better with the Vetter and Lowers than it did without: the extra-long intake tube of the backward-backing inlet duct worked well up to our 55 MPH speed limit then, but above 80 MPH it fell flatter like a switch was thrown when riding the bare bike. Bolting the Fairing with Lowers on the bike made it rocket to 100 MPH, no other changes made. The new airbox design had a long, wide, increased-volume inlet vent that picked air from very close to the engine's cases where laminar flow out on the hiway is thicker: that ends from turbulence at around 80 MPH, though, on the bare bike. So, those bikes had a better "launch" than the K bikes did, despite having less cam at launch speeds, because the airflow to the carb bodies was much quieter - but my K2 could outrun one top end (although I did have a port job in mine by then) at 126 MPH.

That's why the German inlet vent also helps carbs work better. Quieting the noise from within also quiets the air enroute. Here in Colorado, the [in]famous Yamaha 1100 Four had an air vent with an opening like the thickness of my little finger, about 4" long, but it was all the way up underneath the bike's seat. Those bikes did not lose power at Rocky mountain altitudes until over 10,000 feet, while all others (even my 750 with Vetter's Lowers) start losing it about 8500 feet. It showed that if you can make a sizeable plenum, then pump it with still, quiet, hi-pressure air, then you will push more air thru the carbs and it will mix more evenly for lack of turbulence. The USA vent in the 500/550 is just an open oval hole above the airbox, but Honda spent a LOT of Yen in the CB350F to make an elaborate airbox for high-pressure, dead-still air to feed those tiny bores: if you lose that on the 350F, the bike will not even reach 75 MPH, while touching 100 MPH when all together. My "suspicion" is that the effort to create that German air linlet on the 500/550 design benefitted the 350F.

That's my 2 cents on the topic, anyway. It was pieced together from many sources over about 5 years' time, back in the 1970s.

[HondaMan]

Have you mentioned that the UK model ranges, specs and parts fitted are different for both the 500 and 550?

I'm a little "short" in that area (other than mentioning it) due to lack of hands-on experience with the Euro bikes (other than 1 of them). It's hard to learn something you've never seen? 

I agree Mark. Maybe put a mention in the front of the book that only USA models / specs etc are covered and the rest of the world has different models and varients. It's very confusing for many owners here in UK (and other countries I expect) when, as an example, the UK had the 500K1 up until late 1975 and we didn't get any 550 model at all until the F1 in 1976 and in USA the model range was totally different. Plus, in USA bike models are refered to by their model year, in UK they are only know by the actual model, ie, 500K0,500K1,550F1 and F2 and 550K3, that is entire model range for 500/550 from 1971-1978.

That's a good idea, and a good way to do it! I have a 'preface', I think I'll add that to it.

[Nurse Julie]

Have you mentioned that the UK model ranges, specs and parts fitted are different for both the 500 and 550?

I'm a little "short" in that area (other than mentioning it) due to lack of hands-on experience with the Euro bikes (other than 1 of them). It's hard to learn something you've never seen? 

I agree Mark. Maybe put a mention in the front of the book that only USA models / specs etc are covered and the rest of the world has different models and varients. It's very confusing for many owners here in UK (and other countries I expect) when, as an example, the UK had the 500K1 up until late 1975 and we didn't get any 550 model at all until the F1 in 1976 and in USA the model range was totally different. Plus, in USA bike models are refered to by their model year, in UK they are only know by the actual model, ie, 500K0,500K1,550F1 and F2 and 550K3, that is entire model range for 500/550 from 1971-1978.

That's a good idea, and a good way to do it! I have a 'preface', I think I'll add that to it.

👍👍👍

[Deltarider]

I agree a 100%. What I've posted above might serve as some background for Hondaman. It would be too much to expect all these details in a book and I don't expect that. It would make it unreadable. That's why my first line iwas: "I don't know if this is of any importance for your project, but here is some info." 

[HondaMan]

I agree a 100%. What I've posted above might serve as some background for Hondaman. It would be too much to expect all these details in a book and I don't expect that. It would make it unreadable. That's why my first line iwas: "I don't know if this is of any importance for your project, but here is some info." 

I actually covet your input: the bike sold like mad in Europe and has, from what I've seen, about 4 distinct variants based on the country it was sold in(!). I've leaned toward the scant info I've found on the German ones just because the few guys I've talked with there are real knowledgeable: the down side is that they only owned their 500 for 2 years apiece, and a long time ago, when those were young. One has a Beemer now (with my transistor ignition!) and the other has not responded in a long time. A little clue goes a long way because the design is simple: from the actually-produced-by-Honda differences there is much that can be inferred.

For example, the mainjet being smaller in Germany tells volumes about where in the throttle range the carbs stop working. The Keihin carbs before the PD series were usually (and accurately) thought of as having 3/4 of their throat size as the 'working carb size' mostly because, with the exception of those 1960s-era CB/CL250 Hawks and their 3-jet carbs, the carbs did nothing different at 100% open than at 75% open (except make more noise). Those earlier ones had "power jets" in them, which kicked in around 60% throttle and above, and they could actually reach 100 MPH because of them (laying down on the tank, no winds). They could outrun the 305cc SuperHawks at first 305cc production, and this became enough of an issue that Honda quit using the power-jet carbs in the 250 first, then hopped up the 305 in its last year (10/67 thru 2/68) of production with bigger valves. The 350 fully outdid the 305 purely because of the magnificent diaphragm-controlled carbs those 350 bikes have - if you can keep them in working diaphragms, that is...the 305 engine was reliable like an anvil, the 350 not quite so much.

[bender01]

No input other than I need to do my weeping gasket.. someday.
The super tight rolled paper towel has been holding 17 years.
Ill buy a signed copy like my 750 one.

[HondaMan]

Delta: is this the airbox inlet vent you were mentioning for the German bikes, or did they have a different one?

[HondaMan]

On page 72 Clutch adjustment: the clutch depicted is wrong. Our K2 still had the clutch adjustment LH side, be it that the clutch adjuster had been modified.

What was different in that clutch lifter as compared with the early version?
Do you know if the clutch rod was still the same one as before?

[bryanj]

Dont think it was a mod, more of a supercision, the pushrod started as steel, went to the alloy with steel ends and i think back to steel if available, the only reason i can think of is Honda supplied a "kit" to modify the neutal and gear detent and in this kit was the different clutch plates, clutch cover, and the pushrod.
The first clutches used to slip when pulling away and i can only think it was altered to reduce the weight so clutch would grip quicker.
The mod bulletin is on the uk site, i will try and screenshot it later for you if you havent got it already

[Deltarider]

I know little about the pushrod. Mine is very light and since it never gave a problem (in contrast to what you read in this forum), I looked it up in various CB500 Parts Lists and noticed the partnumber had changed: from serial no. CB500E 1018728 on it is 22850-323-000, where earlier builds had 22850-292-020. The latter rod was also on 41 other Honda bikes: mainly CB450s and CB500Ts.
Also the clutch adjuster on mine never gave a problem, again in contrast to what you read in this forum (I may have greased it 4 times at the most in over 44 years and over 100.000km). So I looked that part up as well: mine has PN 22841-323-000. The CB500K2-A, the last CB500 model in the US, still had the 22841-266-000 which was shared by 82 other Honda bikes. I can't tell the difference. I am no expert.
Another part that wasn't a problem so far, is the swing arm. I may have succeeded in greasing it 4 times. Most of the times I didn't manage to get the grease in and I gave up. So when I read about complaints others had, I looked it up in parts lists to see why it is mine never gave a problem. Turns out mine was slightly different. It's the model with one grease nipple underneath, in contrast to previous models that had two nipples (on the sides of the frame). You can look it up yourself either at CMSNL or in p.64 in https://www.honda4fun.com/dwnload/Part-List/CB500/CB500-K2-76-Parts-List.pdf . Maybe you can interpret if the design has been an improvement or not. I am no expert.
Actually I have quite a list of parts on my bike that never gave a problem. Some here like to ridicule this, but it's the truth. I dont have the itchy hands others may have. My bike is 49 years old, has done over 140.000 km (88.000 miles) and still has the original primary chain. In short: when I see all the issues others had, I can only say that I don't recognise my bike, not at all. However one part I have not been lucky with, is the camchain tensioner. The one in it now, is the third. It seems I never manage to do more than some 48.000km (30.000 miles) with it.
I didn't have to change the forkseals nor the front springs. Although I have bought 4 new rubber carb-head boots decades ago; they're still in their plastic bags, simply because I have no indication the original ones leak. Same for the O-rings at the fuel T-joints. They're still the ones the bike got at the assembly line. I can't help it: I will not fix things that are not broken. Look, it's different when you do a total overhaul and are deep inside the engine. Ofcourse you will renew all rubber seals. But, why would I disassemble the caliper pivot pin to grease it, when it still swings as new? I check this every year at the start of the season and I don't ride in nasty weather. That part is very accessible and I can always do it when needed. Again: the two new small O-rings are still in the plastic bag.
I do what is needed. When I diagnosed an airleak, I have replaced both O-rings on one of the two carb-head manifolds. The two on the other manifold tell me they can live long if you leave them alone. Again: an airleak is is easily detected: the engine will tell you.
Realise that apart from 5 months hibernation, my bike has always been in use. The best is to ride them daily. Maybe I should translate the interview with an owner of a CB500K1, who rode his bike every day of the year. Everyday the same stretch to where he worked. At the time of the inerview his bike had covered 220.000kms and the engine had not been opened yet. Maintenance was done by his Honda dealer. He rode it like an old man, never over 5500RPM.

[bryanj]

The bulletin is a 4 page one which i hope is visible in the attachments and shows which way the slanted clutch fibres should go among other things. Page 4 gives a list of the parts in the kit.

Mark, the quality of reproduction here is not good if you wish i will photocopy and paste all the 500 four bulletins to you just pm me your address, i also have the PDI and build from crate instructions should you want them.

[Deltarider]

Better resolution is in this here site: http://manuals.sohc4.net/cb500/
The idea of the slanted friction disks was that the oil had a longer route and the clutch as a result would be softer and even easier to operate than with straight. However mechanics usually favoured the clutch friction disks with straight lines over the slanted ones. When I had to replace both springs* and friction disks after around 80.000km I choose the 22201-KY2-000 ones and they're fine.
BTW, for who is interested, CMSNL has two of the kit, Bryanj mentioned, left. PN: 06241-323-000 € 305,50.
*Springs had reached exactly the min. length of 30,5mm.

[HondaMan]

I know little about the pushrod. Mine is very light and since it never gave a problem (in contrast to what you read in this forum), I looked it up in various CB500 Parts Lists and noticed the partnumber had changed: from serial no. CB500E 1018728 on it is 22850-323-000, where earlier builds had 22850-292-020. The latter rod was also on 41 other Honda bikes: mainly CB450s and CB500Ts.
Also the clutch adjuster on mine never gave a problem, again in contrast to what you read in this forum (I may have greased it 4 times at the most in over 44 years and over 100.000km). So I looked that part up as well: mine has PN 22841-323-000. The CB500K2-A, the last CB500 model in the US, still had the 22841-266-000 which was shared by 82 other Honda bikes. I can't tell the difference. I am no expert.
Another part that wasn't a problem so far, is the swing arm. I may have succeeded in greasing it 4 times. Most of the times I didn't manage to get the grease in and I gave up. So when I read about complaints others had, I looked it up in parts lists to see why it is mine never gave a problem. Turns out mine was slightly different. It's the model with one grease nipple underneath, in contrast to previous models that had two nipples (on the sides of the frame). You can look it up yourself either at CMSNL or in p.64 in https://www.honda4fun.com/dwnload/Part-List/CB500/CB500-K2-76-Parts-List.pdf . Maybe you can interpret if the design has been an improvement or not. I am no expert.
Actually I have quite a list of parts on my bike that never gave a problem. Some here like to ridicule this, but it's the truth. I dont have the itchy hands others may have. My bike is 49 years old, has done over 140.000 km (88.000 miles) and still has the original primary chain. In short: when I see all the issues others had, I can only say that I don't recognise my bike, not at all. However one part I have not been lucky with, is the camchain tensioner. The one in it now, is the third. It seems I never manage to do more than some 48.000km (30.000 miles) with it.
I didn't have to change the forkseals nor the front springs. Although I have bought 4 new rubber carb-head boots decades ago; they're still in their plastic bags, simply because I have no indication the original ones leak. Same for the O-rings at the fuel T-joints. They're still the ones the bike got at the assembly line. I can't help it: I will not fix things that are not broken. Look, it's different when you do a total overhaul and are deep inside the engine. Ofcourse you will renew all rubber seals. But, why would I disassemble the caliper pivot pin to grease it, when it still swings as new? I check this every year at the start of the season and I don't ride in nasty weather. That part is very accessible and I can always do it when needed. Again: the two new small O-rings are still in the plastic bag.
I do what is needed. When I diagnosed an airleak, I have replaced both O-rings on one of the two carb-head manifolds. The two on the other manifold tell me they can live long if you leave them alone. Again: an airleak is is easily detected: the engine will tell you.
Realise that apart from 5 months hibernation, my bike has always been in use. The best is to ride them daily. Maybe I should translate the interview with an owner of a CB500K1, who rode his bike every day of the year. Everyday the same stretch to where he worked. At the time of the inerview his bike had covered 220.000kms and the engine had not been opened yet. Maintenance was done by his Honda dealer. He rode it like an old man, never over 5500RPM.

Boy, do you have it right! I have LONG found that the best preservation of these bikes is the weekly use of them. Those that get parked for long periods of time also get ignored, and then  moisture then eats at them as corrosion. The worst single thing that could happen to the carbs, for example, is to have them parked and dried out with the last gas being MTBE-laced, no chance of rinsing it off (it is an acid). Then every time the humidity rises that acid gets active again. A splash of oil on them suspends the MTBE so it cannot act: it binds to the loose-end molecule that makes it acidic.

Even my own 750 suffered the "ran when parked" torture between 2001 and 2006 when I had cancer and was recovering (didn't ride for a while). I had to tear the engine down to figure out why it wouldn't start (picture of the head is in my book!). It ran 100+ MPH the week that I parked it before that. My carbs were saved, though, due to oil in the gas at every fillup, and it had MTBE-laced gas in it while parked those 5+ years.

The swingarm pivots, also when parked, will rust. Then when ridden again, they eat the swingarm collar with rust grit, making loose and gritty metal fines. You can figure out the rest of it from there...the same goes for the wheel bearings: when rolled enough they dry moisture out of their grease. If sitting long enough, the grease instead absorbs the moisture and applies it neatly to the ball bearings equally. I see it frequently when they come to me for help.

That picture of a tiny air inlet duct is something I've never seen before. It would reduce noise for sure (not that the 500 is noisy?), but will also restrict airflow above approximately 6800 RPM, if that slot width in the cover is the same size as in the other bikes, as the opening is only about the size of 2 carb throats. Then you would have to lean out the mainjet under normal circumstances or it would start running richer - although that also depends on which carburetors were used with that inlet. If they are the PD carbs then it wouldn't matter that much as they start falling lean anyway above 6000 RPM because of their single-hose fuel feed rate. Interesting change!

[HondaMan]

Dont think it was a mod, more of a supercision, the pushrod started as steel, went to the alloy with steel ends and i think back to steel if available, the only reason i can think of is Honda supplied a "kit" to modify the neutal and gear detent and in this kit was the different clutch plates, clutch cover, and the pushrod.
The first clutches used to slip when pulling away and i can only think it was altered to reduce the weight so clutch would grip quicker.
The mod bulletin is on the uk site, i will try and screenshot it later for you if you havent got it already

In the early CB500 here (K1/2) the clutches had the "pinwheel"-like cork shapes. If you had a cold engine and tried to take off hard and fast, the clutch would not grab all the way through 1st gear and through a good part of 2nd as well. After warmup it got better, but still slipped a long time in 1st from a hard takeoff. I first got involved with all that because my brother ran the State of Missouri's Texas County Ambulance service, which required a 3-minute response from his pager beep call. He would run to the garage where his CB500 was facing the door, opening the door as he ran, jump on the bike and start it, and as soon as the oil light went out, he was off. He lived 1.2 miles from where the ambulance was kept. He called me, griping that his "500 clutch never grabbed all the way to the ambulance", which launched me into the world of "why?" back in late 1972. After replacing his cork plates with the square-cut ones instead (I think we used some of the same thickness from another Honda at the time, as Honda's own were still slant-cut for the 500 then) he could (and did) burn rubber from the garage launch. He said it saved him 10 seconds (?) enroute to the ambulance.

After that, I never installed slant-cut corks into the 500 clutches, and lots of owners liked it better.

[Deltarider]

Indeed, as far as my own bike, I have had very little issues and I'd say two out of three had to do with prolonged inactivity like in hibernation. In this forum it has been my mistake to asume all CB500/550s  have been used as regularly as mine. Video's on Youtube have learned me that many actually have been sitting for years if not decades collecting dust whilst offering shelter to generations of mice. Rusted tanks, fouled carbs and seized calipers were the result. Ofcourse Honda's R&D can not be held responsible for not using your bike.

[bryanj]

I think it was 450 plates Mark, attached screenshot from a cb500k0 parts book with hand written anotation

[MRieck]

Does the new book show how to assemble the cases in the "normal" fashion (crankshaft sitting in upper case?"

[HondaMan]

Does the new book show how to assemble the cases in the "normal" fashion (crankshaft sitting in upper case?"

Yep, this time I chose to do it my "normal" way (which is that way), since I do the 750 upside-down and it's habit, largely(!). It's not hard to do, just seems strange to some builders to leave a gear lying loose in the case while closing them up? It usually lies in just the right spot all by itself, and the primary shaft slides right in.

I did take this one apart in the "upright" position just because I hadn't done it that way before and it has been mentioned here in the forum before: then I had to rebolt it together again to show it being taken apart upside-down again for the book.

Then again, that engine has been re-reassembled something like 6 times now, because I kept forgetting another picture... 

[HondaMan]

I think it was 450 plates Mark, attached screenshot from a cb500k0 parts book with hand written anotation

I think you're right, Bryan: I serviced a small herd of 450s in that shop. They were real popular with the college kids (which was much of that town's economy then) and they had both CB and CL versions, quite a few of them. So, I stocked parts for them.

[Deltarider]

As far as I know the CB450Ks originally did not have the slanted version friction disks. Not that it matters much: they're interchangable. IIRC the slanted ones were first introduced on later CB500s. Partnumber went from 22201-323-000 to 22201-323-010.

[Oddjob]

Personally I'd mention how to test the primary chain to see how worn it is, if you're replacing the primary chain then you MUST replace the primary damper rubbers at the same time or you shorten the life of the new chain.

Replacement gearbox selectors are available, NOS ones are very rare and expensive when you can find one. I've got a set of the replacement selectors and they are much better made and finished than the standard Honda ones.

Did you know the reason that the 500 seat breaks the seat pan just where the hinges are is because it doesn't fit the frame properly, the rear rubber is too thin and a pillion on there ends up snapping the seat pan because of that? Of course, don't carry pillions and it's not a problem  before I get all the "well my seat has never broken comments"

Maybe a mention of fitting a CB650 primary chain tensioner is worthwhile, a mod I have done.

Also a mention of how to replace the rubbers in the clutch basket, as these get older the rubbers are getting harder. Interestingly, the 550 suffers far more than the 500 in that department, I've taken about 10 baskets apart and most of the 500 rubbers were still ok, all the 550 rubbers weren't. It's a simple mod but worthwhile doing to reduce knocking at tickover.

As for the pushrod, maybe people can read Mike Nixons comments on why it was made a 3 piece construction. https://www.motorcycleproject.com/cb500/cb500_pushrod.html

[RAFster122s]

How do you rerivet the primary drive back together after replacing the dampners? Where do you get the rivets?