Honda Twins banner

1 - 20 of 32 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Hey Folks. Some quick background which you can skip if you would like. I grew up wrenching on cars and have done everything myself for the last 16 years from small maintenance, to axles swaps, to tranny replacements on older vehicles etc. i'm comfortable taking anything apart, but i certainly wouldn't say i am an expert in all things mechanical. However i greatly believe in research, research, research first . . . and the information and answers are out there. I have been researching on this forum as well as a few other places (and the Honda service and repair guide) for the last 4 days straight. I have learned a lot, but also recognize that many of you have incredible experience and in short would like to run this scenario past members to see if the diagnosis makes sense.

I'm looking to buy a bike, its a '72 CB450. According to the owner it has been sitting for the last 2 years because the valve guides went bad and according to his original post, burns oil when letting off at high RPM's. He is selling because he has too many projects and doesn't have the time. I have researched this issue, I have learned a lot, and i understand that for this to be fixed correctly i would have to remove the head and really send it out to make sure the new valve guides are put in properly. I think where i am a little wary is this:

Should this failure have really rendered it NOT running and un-ridable for the last 2 years? I could see it not running well, losing compression, and not something you would want to ride to prevent damage, but i'm suprised that it won't even start. When i ask if it started his response was that he could "probably get it to run with starter fluid".

He assures me he knows exactly what is needed, did a compression test and put a scope on it, and that the motor still turns over when he kicks it so its not locked up. I'm basically asking the brains and "gods" of this forum their opinion on if this smells fishy or seems reasonable before i go back and setup a meeting in person with a lot of questions.

To conclude, i'm not shy of any amount of work, but this will be my first bike (visually in great shape) and definitely a learning experience/winter project. I'm assuming in addition to the valve guide issue that after sitting for 2 years i will have to do a full tune up, fluid change, and replace any valve/piston/etc seals that may have gotten dry and cracked in the meantime.

I'm open to any and all feedback here, but my main focus is, DOES this sound realistic?

THANKS ALL!
 

·
Registered
Joined
·
6,495 Posts
Smoke when decelerating is a classic symptom of valve guides.
It's not surprising at all that it won't start after sitting for two years, but that probably isn't due to valve guides - more likely gummed up carbs or timing.
Valve guides will require complete disassembly of the top end - they're fairly cheap to have a machine shop do them (recommended).
While it's apart you might as well have the machinist examine the cylinders and pistons.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #3
Thank you Bill. Obviously you are a great resource on this (and potential candidate for the service work should i move forward and want to ship the head to you? i believe i found your name a few times during my research)

i think that is my main questions too which I'm working on clarifying . . . will it not start because of supposed valve guide issue . . . or because its been sitting. Thanks again!
 

·
Administrator
Joined
·
13,061 Posts
Thank you Bill. Obviously you are a great resource on this (and potential candidate for the service work should i move forward and want to ship the head to you? i believe i found your name a few times during my research)

i think that is my main questions too which I'm working on clarifying . . . will it not start because of supposed valve guide issue . . . or because its been sitting. Thanks again!
The bike will not be kept from starting by worn valve guides as mentioned above, it's most likely carbs are dirty which is why the seller referred to using starting fluid to show that the engine will run. If you can post some pictures of the bike you'd like to buy, or the ad if it is advertised, that would help us give you a little more info and opinion
 

·
Registered
Joined
·
8 Posts
Discussion Starter #7
Sounds reasonable. And yea after 2 years I assumed i would have to run through a carb cleaning, fluid change, maybe pull the plugs and put a few drops of oil in for the piston rings. I have been scanning for a potential light restore candidate for about 6 months now . . . this bike aesthetically is certainly above what i was originally planning on to purchase, but its a beautiful build (IMHO, probably not everybody's cup of tea) and i'd rather focus on the mechanical components then the "dress up" part of the build anyways!

Pictures below at the request of @ancientdad

72593316_10157680017954721_575839218996084736_n.jpg
72831704_10157679997499721_2594734660005134336_n.jpg
72410205_10157679997804721_3716793654904356864_n.jpg
72461521_10157679998129721_5511399761913053184_n.jpg
 

·
Administrator
Joined
·
13,061 Posts
Sounds reasonable. And yea after 2 years I assumed i would have to run through a carb cleaning, fluid change, maybe pull the plugs and put a few drops of oil in for the piston rings. I have been scanning for a potential light restore candidate for about 6 months now . . . this bike aesthetically is certainly above what i was originally planning on to purchase, but its a beautiful build (IMHO, probably not everybody's cup of tea) and i'd rather focus on the mechanical components then the "dress up" part of the build anyways!
Mechanically, I'd go over all the necessary adjustments to the engine, change the oil and clean the centrifugal filter and look into the interesting approach to rear brake actuation first. As for oiling, you have bigger concerns than the rings on this engine... the DOHC 450 is unique in that it holds no residual oil beneath the cams and followers to help with lubrication until the oil flow reaches the top end on a cold start. Oil flow takes a full 1 to 2 minutes to properly travel up the 2 right hand cylinders studs from the oil pump and filter area, then into the right side cam bearings and fill the camshafts to lube the cam bearings on both ends and out the orifices in the lobes to lube the followers, so keeping the revs low on cold starts for the first couple minutes is important to avoid excess cam lobe and follower wear. I see the petcock is off in the 3rd picture, and you should make sure it's always turned off when you turn off the key as these carbs are known to seep fuel past the float needles and past an open intake valve down into the crankcase if the fuel is left on, diluting the oil and causing top end damage. You can download a FSM (factory shop manual) here
 

·
Registered
Joined
·
6,495 Posts
Thank you Bill. Obviously you are a great resource on this (and potential candidate for the service work should i move forward and want to ship the head to you? i believe i found your name a few times during my research)

i think that is my main questions too which I'm working on clarifying . . . will it not start because of supposed valve guide issue . . . or because its been sitting. Thanks again!
You should also perform the "acetone test" on the valves to make sure there's no leakage.
 

·
Premium Member
Joined
·
1,927 Posts
. . . I'm looking to buy a bike, its a '72 CB450. According to the owner it has been sitting for the last 2 years because the valve guides went bad and according to his original post, burns oil when letting off at high RPM's. He is selling because he has too many projects and doesn't have the time.
I seriously doubt that the valve guides are the reason this thing is parked. It looks like he has done the maximum possible damage to that poor old CB450 and wants to move on to his next victim.

I have researched this issue, I have learned a lot, and i understand that for this to be fixed correctly i would have to remove the head and really send it out to make sure the new valve guides are put in properly. I think where i am a little wary is this:

Should this failure have really rendered it NOT running and un-ridable for the last 2 years? I could see it not running well, losing compression, and not something you would want to ride to prevent damage, but i'm suprised that it won't even start. When i ask if it started his response was that he could "probably get it to run with starter fluid".
While you could physically remove the head and send it to someone to replace valve guides, the head would then be worth way more than the rest of the bike. The pictures show one of the most horribly mutilated and debauched Hondas I have ever seen. You are correct to be surprised that it won't even start. It could be entertaining to accept his offer of getting it started with starter fluid. If you make that challenge, and he agrees, stand back when he tries it. Stand way back.

He assures me he knows exactly what is needed, did a compression test and put a scope on it, and that the motor still turns over when he kicks it so its not locked up. I'm basically asking the brains and "gods" of this forum their opinion on if this smells fishy or seems reasonable before i go back and setup a meeting in person with a lot of questions.
I am neither a "brain" nor a "god" of this forum, but yes-- it smells as fishy as a perch left in the direct sun for five or six days.

To conclude, i'm not shy of any amount of work, but this will be my first bike (visually in great shape) and definitely a learning experience/winter project. I'm assuming in addition to the valve guide issue that after sitting for 2 years i will have to do a full tune up, fluid change, and replace any valve/piston/etc seals that may have gotten dry and cracked in the meantime.

I'm open to any and all feedback here, but my main focus is, DOES this sound realistic?
This bike has absolutely no socially redeeming value left. He has gutted its very soul. It is not worth a dollar per cc, it is not worth a nickel per cc. There is nothing you could even learn by buying it and taking it to pieces as exploratory surgery. It is so messed up already that there is nothing you can learn from it. In fact, studying the remains of this machine could give you a perverted perception of motorcycles for the rest of your life. In the future, if you see a bike with a brown seat, missing fenders, missing chain guard, clip-on handlebars, loosely assembled rear-sets, a home made, barely attached exhaust system wrapped up in pipe bandages, velocity stacks on the carburetors, melted yellow plastic used as visual highlights, rattle can paint peeling from the remaining chrome on the wheel rims, foam insulation plugging holes in the oil filter cover, etc., etc., etc., run -- don't walk away from it. It has been put together by some poor soul hooked on meth.

This is, of course, only my opinion, and you did ask for our opinions. I don't mean to be unkind. I am trying to help you avoid a sad experience.
 

·
Registered
Joined
·
6,495 Posts
I replied before you posted the photos - Ray is harsh, but honest.
On the other hand, mine was much worse than that when I started, but with a lot of work and transplanted parts it turned out pretty well.
Just depends on how much of both you are willing to put into it.
 

Attachments

·
Registered
Joined
·
703 Posts
This bike has absolutely no socially redeeming value left. He has gutted its very soul. It is not worth a dollar per cc, it is not worth a nickel per cc. There is nothing you could even learn by buying it and taking it to pieces as exploratory surgery. It is so messed up already that there is nothing you can learn from it. In fact, studying the remains of this machine could give you a perverted perception of motorcycles for the rest of your life. In the future, if you see a bike with a brown seat, missing fenders, missing chain guard, clip-on handlebars, loosely assembled rear-sets, a home made, barely attached exhaust system wrapped up in pipe bandages, velocity stacks on the carburetors, melted yellow plastic used as visual highlights, rattle can paint peeling from the remaining chrome on the wheel rims, foam insulation plugging holes in the oil filter cover, etc., etc., etc., run -- don't walk away from it. It has been put together by some poor soul hooked on meth.

This is, of course, only my opinion, and you did ask for our opinions. I don't mean to be unkind. I am trying to help you avoid a sad experience.
:D:D

I like the bike. I wouldn't strip my own down to turn it into a cafe style bike like that, but (with maybe some of the worst excesses removed) I wouldn't kick that thing out of the garage.

My 2c.

Any non-runner is fairly high risk. Any problems with the head on the 450 and the engine has to come out, and there's potential for a lot of woes in there. Same is true btw even if the engine were running, but running poorly. The problem with most older bikes like that is what you're looking at is the sum total of all of the effort and spannering previous owners/sellers/resellers have foisted on the bike - good bad and indifferent. If you priced it accordingly - and don't mind lots of spannering, head-scratching and accept it might lead more money spending on it - then why not ?

Just don't pay too much for it with all of the risk that could be hidden in there.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #13
Ok @fxray you gave me a very good laugh and i enjoyed your comments so much i read this TWICE! I know that there are plenty that like the "stripped down cafe racer, scrambler" style build, and i know that there are many that hate it because of the bad name it has given motorcyclists and the field of essentially ruined, scrapped, and cheap builds left in its wake, and wasted old twins in a graveyard because frames have been cut beyond restoration.
I will get this out of the way, I am unfortunately in the category of people that like the aesthetic of the cafe racer/scrambler build. I know, shoot me. perhaps i'm the problem :grin: i hate myself too sometimes. And admittedly, to make matters worse, this is my first bike, which probably makes me even worse since (as you accurately pointed out) i don't have a platform to start on coming from a NORMAL unmolested bike. Perhaps its just the stripped down, barebones, more classic looking feel i like. Perhaps i have romantic visions of me wrenching on my bike in my garage while sipping a whiskey with my dogs. At least i DON'T have a waxed mustache, corduroy overalls, and talk for hours about coffee variances :p But I do realize i am tip-toeing dangerously close to what you probably hate about new motorcyclists. All i know at the end of the day is, i like them, and this build looks better then most (to me). I completely understand why they get the hate they do, and i fully expected a post like this when the pictures went up. While some of what you said is an opinion of the end look of the bike (which still has value), you brought up a few other things from a more mechanical standpoint.

So that said after my confession, let me get the more technical mechanical parts of what you said, bc you bring great insight.

I seriously doubt that the valve guides are the reason this thing is parked. It looks like he has done the maximum possible damage to that poor old CB450 and wants to move on to his next victim.

While you could physically remove the head and send it to someone to replace valve guides, the head would then be worth way more than the rest of the bike. The pictures show one of the most horribly mutilated and debauched Hondas I have ever seen. You are correct to be surprised that it won't even start. It could be entertaining to accept his offer of getting it started with starter fluid. If you make that challenge, and he agrees, stand back when he tries it. Stand way back.
would like more from a mechanical perspective of what makes this mutilated, debauched, and maximum popular damage. see below.

I am neither a "brain" nor a "god" of this forum, but yes-- it smells as fishy as a perch left in the direct sun for five or six days.
Don't you do that to yourself. You are doing great, more brains then you give yourself credit for :thumbsup:

This bike has absolutely no socially redeeming value left. He has gutted its very soul. It is not worth a dollar per cc, it is not worth a nickel per cc. There is nothing you could even learn by buying it and taking it to pieces as exploratory surgery. It is so messed up already that there is nothing you can learn from it. In fact, studying the remains of this machine could give you a perverted perception of motorcycles for the rest of your life. In the future, if you see a bike with a brown seat, missing fenders, missing chain guard, clip-on handlebars, loosely assembled rear-sets, a home made, barely attached exhaust system wrapped up in pipe bandages, velocity stacks on the carburetors, melted yellow plastic used as visual highlights, rattle can paint peeling from the remaining chrome on the wheel rims, foam insulation plugging holes in the oil filter cover, etc., etc., etc., run -- don't walk away from it. It has been put together by some poor soul hooked on meth.

This is, of course, only my opinion, and you did ask for our opinions. I don't mean to be unkind. I am trying to help you avoid a sad experience.


So you bring up a good point in order:
1) hard for me to do surgery on a frankenstein, when i have never worked on a normal body. As much as i want to own and build my custom bike, a more modest approach is probably more reasonable for me, even tho i don't want to admit it.
2) MODIFICATIONS YOU LISTED:
- Brown Seat: Well thats just silly, brown can do just as good as black
- missing fenders: looks cool, and who doesn't want a rock to the face? (read: point taken and understood)
- Missing chain gaurd: i show my ignorance in that i didn't even notice that
- clip on handlebars: All the rage, i prefer something a bit higher, but its a preference. at least it appears he adjusted the foot pegs for that riding style of a low handlebars (flame suit on because i realize i may be incorrect)
- loosely assembled rear sets: THIS caught my attention. do you see evidence of that in the pictures?
- Homemade, barely attached exhaust: Is this an assumption based of this (and other cafe) build(s) or do you see evidence of this? I know you guys probably hate that mummy wrapping tape, but hey Halloween is coming right?
- melted yellow plastic: Worse. According to seller i think what you see is gold plating he put on metal accent pieces. dumb idea bc that obviously wouldn't hold up to road use and it is clearly pitted and coming off. no matter to me, i would sand and polish all of that off anyways.
- rattle can paint on rims: good eye! didn't notice that one.

just to clarify, i am making good fun but i thoroughly enjoyed your post. it made me laugh and you were spot on on some stuff. i hope you don't mind me being jovial back. If i ever get my cafe racer build together you seem like the sort i'd love to have a beer with so you can give me the tongue lashing i (maybe) deserve and tell me why my bike is dumb.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #14
:D:D

I like the bike. I wouldn't strip my own down to turn it into a cafe style bike like that, but (with maybe some of the worst excesses removed) I wouldn't kick that thing out of the garage.

My 2c.

Any non-runner is fairly high risk. Any problems with the head on the 450 and the engine has to come out, and there's potential for a lot of woes in there. Same is true btw even if the engine were running, but running poorly. The problem with most older bikes like that is what you're looking at is the sum total of all of the effort and spannering previous owners/sellers/resellers have foisted on the bike - good bad and indifferent. If you priced it accordingly - and don't mind lots of spannering, head-scratching and accept it might lead more money spending on it - then why not ?

Just don't pay too much for it with all of the risk that could be hidden in there.
You bring up some additionally good points. I'm walking into a medium-high risk situation because she is currently a non starter. I believe my first assumption was i could do a carb rebuild, motor tuneup, replace all fluids, batteries, gaskets as necessary with any bike sitting for a few years and then get her running roughly. then from there tackle the valve/valve guide issue with some personal time/elbow grease, and send the head off for a few hundred per guide and have her running like a sowing machine. Perhaps i'm being a bit of an optimist. Thanks for not totally hating the bike! I don't love everything about it myself, but 90% of it I do like.
 

·
Premium Member
Joined
·
1,927 Posts
smcparland,

You are stepping into this with your eyes wide open. You are not the naive first timer that I incorrectly perceived at first. In that case, if this bike suits your taste, by all means go for it. Whatever the end goal is, garage time with your dogs is priceless. I salute that and wish you well!
 

·
Registered
Joined
·
2,373 Posts
Smartest people in the room already spoke but....You can find 450s unmolested that run, hell are also rideable but need some extra attention to run properly all day online, you just have to be patient and do the research.
End of the season before Winter is the best time to buy as sellers are often scrambling to find proper storage and reluctant to spend any more time or $ on a bike they're already selling. I've seen nice, properly running & titled 450s from $1800-$2,200 without the "it ran when I parked it" bull.

Personally, I always shy away from "seller says they know exactly what is needed to make it run correctly..." IF that was always the case, the bike would be ridden and offered in a properly running state. Pass.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #17
smcparland,

You are stepping into this with your eyes wide open. You are not the naive first timer that I incorrectly perceived at first. In that case, if this bike suits your taste, by all means go for it. Whatever the end goal is, garage time with your dogs is priceless. I salute that and wish you well!
My eyes may be wide open, but that does not mean that I am not naive, inexperienced, or woefully optimistic :grin:. Garage time with dogs is good, but money spent and a pile of parts make the wife less then happy with the endeavor! Especially considering that this is approaching a 50 year old bike, with some unique design characteristics to begin with, and potentially some almost insurmountable hurdles, i HIGHLY value the input of you and the rest of group on this forum on whether the mechanical motor restoration of this will be more problematic/expensive then it is most likely worth. Aesthetics aside.

PS. The garage isn't heated, so the time may be less then priceless as well.
 

·
Registered
Joined
·
500 Posts
I think.....
if this were a bike that only had one or two made and are truly rare, that a custom is perhaps sacrilege of the first order. This bike does not fit that category.

For me, I guess the basic challenge of keeping the blasted thing running and on the road beats any styling issues and I can appreciate the creativity that went into it to get where it is today. Nothing mechanical lasts forever, you will have maintenance. Parts are more and more scarce with rarity's associated cost. Styling was only modestly good even when new. The early years were horrible, K0 ref. I love the 67/68/69 styling, I have three! K1/K2. Subsequent years? meh, they should be customized to fix their inherent fugliness. I think the blue fog of a 50 yo bike using a bit of oil is charming, even accepted.

Of course, I've been known to have a perverse sense of humor, as well as never being accused of being anywhere close to normal.

So keep it running and forget cost, these things were a labor of love 20 yrs ago when parts were cheap and even available and more-so today.

Having fun yet?
 

·
Registered
Joined
·
6,495 Posts
I'll throw in a little more before you proceed...
The cafe aesthetic is a little like heavy metal music - we did all that back in the '60's, and moved on from it.
One thing I learned is that the riding position offered by your photos is entirely unsuitable, even dangerous.
It will put way too much weight on your hands and be very unstable - your weight should be centered, and you should be able to lift up off the pegs without any weight shift at all.
Anyone who has put their feet back on the rear pegs (stock) at speed has learned that's a bad position. It's common for guys to put their rear sets at the rear peg mounts, and this is an unstable position to ride, particularly with real low handlebars - and the faster you go the more unstable it becomes. I did some road racing myself when I was younger, and I learned this through brutal experience.
Take a look at these photos of real road racers - you can see by their number plates that these guys were pretty good - and even the horse jockey - their feet are not much further back than a couple of inches past the swingarm pivot, and they can lift up off the seat easily and without much weight shift fore or aft - well forward of their butts, relatively stable.
 

Attachments

·
Registered
Joined
·
703 Posts
Better add some emergency budget for plates to remount those rearsets 6" further forwards then.. :)

(Is that really Ago himself on that MV pictured above Bill btw - or just some guy who likes the look ?)
 
1 - 20 of 32 Posts
Top