Author Topic: 1976 CB550F - making it good, one step at a time (Read 124843 times)

Restoration Fan · « **Reply #225 on:** June 14, 2015, 06:43:21 AM »

Quote from: flatlander on June 09, 2015, 03:08:47 AM

i'm trying to train her already to help with the bike. today a small package from mike arrived that included the last bits and pieces. she totally loves those cool stickers and immediately studied the timing card for the cam. in no time she noticed that it's a bit updated from the specs that megacycle publish on their site which is valuable info

If you want to rent that dog out to others doing engine rebuilds, you could probably recoup the cost of your bike!

flatlander · « **Reply #226 on:** June 14, 2015, 12:06:38 PM »

stev-o thanks, that's good info. i might just leave off the pucks for now so that i can do the same.

resto fan, not so fast - she still needs to get a bit more handy with the tools. she tries pulling that "no thumbs" card but i'm not buying it!

flatlander · « **Reply #227 on:** June 15, 2015, 05:01:03 AM »

the cam is now doing my head in.
according to the timing card, intake should open 11*BTC and close 50*ABC. with zero valve clearance and at 0.40" lift.
what i get is open 11*BTC and close 14*BBC.

that's pretty far off. on test assembly it squared up better. i must be missing something obvious?
i set the "zero valve clearance" with no.1 piston at TDC, when intake is opening - which is per honda manual. does this need to be different?

flatlander · « **Reply #228 on:** June 17, 2015, 12:06:08 PM »

i called megacycle about the mystery that lilly the dog discovered: the timing values on the website are published in 2012, the ones on the card in 2010 - and they are both different.
they confirmed i should go with the card as those values have been re-measured digitally and are more accurate. the catalogue on the site was published more recently but for many of their cams, contains data that is up to 30 years old.

also, i discovered that i had fooled myself by setting clearance when valves were open, not closed. duh

ok with all this cleared up it's time to get back to work...

Stev-o · « **Reply #229 on:** June 17, 2015, 05:31:14 PM »

Surprised you didnt paint the lower cases while you had her apart.

flatlander · « **Reply #230 on:** June 18, 2015, 02:01:35 AM »

i'm not painting any of the engine parts.

the lower part of the block stayed in the frame so didn't get blasted or polished. as it's been working well and the chains are tight i didn't see any reason in pulling it apart at this stage. if i do go into it some time in the future it will get more of a beauty treatment.
at this point i need to get this thing back on the road as the weather is decent!

flatlander · « **Reply #231 on:** June 24, 2015, 01:05:22 PM »

in case you guys think i've fallen asleep: this thing is going back together, a little bit every day - or sometimes every second day. i'm not making many photos now as it's not too exciting, just everything going back where it belongs.
depending on what else is going on it might be ready during or just after the weekend, yay!

Stev-o · « **Reply #232 on:** June 24, 2015, 07:26:05 PM »

Don't worry, we are here impatiently waiting!

SOHC4 Cafe Racer Fan · « **Reply #233 on:** June 24, 2015, 08:32:16 PM »

Pics or it didn't happen.

Go for it and get her finished.

flatlander · « **Reply #234 on:** June 25, 2015, 06:03:56 AM »

ooooh the pressure, the anticipation!! you certainly don't let me get off easy. ok ok i'll post some interim stuff just to get you guys off my back... probly you need to be some more patient until the weekend though.

flatlander · « **Reply #235 on:** June 29, 2015, 05:12:23 AM »

this turned out quite different than expected:
i received a letter from my good friend the taxman, telling me nicely that he was going to help me avoid having to pay a fine if i returned my declaration for 2014 pretty sharpishly. in previous years we always got an extension but not now. so most of the weekend was spent assembling exciting paperwork and the poor little 550 was feeling very neglected

flatlander · « **Reply #236 on:** July 04, 2015, 03:26:47 AM »

tax stuff is sorted but now this:

i kept having a bad feeling about the cam that i just couldn't get rid of. for peace of mind i went back and checked it again and again and it just didn't want to match up with the timing card no matter what i did. what was i doing wrong ??

after a brief email exchange with mike and sending him some photos he confirmed that the cam must be off. it has the right model number engraved, 12600 but the profile is not to that spec. nice to know that i'm not completely dumb (was really starting to doubt myself) but i'm not looking forward to the hassle and waiting time of getting it replaced. will call megacycle on monday.
between this and the rocker arm bith the botched up thread i'm starting to wonder if anyone there is actually looking at the stuff they ship out?

strynboen · « **Reply #237 on:** July 04, 2015, 02:46:27 PM »

this is vhy i use stock parts.

..they FIT..and kosts less..and fabrik data is in my users manual..easy to go..

nice to have a fast 550...but all 250 Ninjas vill kill you . even it is tuned ..so vhy vaste Money..vhen a stock bike runs abaut 160 kmt..and yours vill only be a littel farster then mine stock..how often runs you a race vith a exact same type bike..i have not meet a cb 550 in years on road..so a race hvere 5-10 hk does the difference are not real in exist..
.....all this Tuborg you have missed..baying hot cams..

flatlander · « **Reply #238 on:** July 05, 2015, 12:02:54 AM »

i know, if i want to compete with modern bikes i need to get a modern bike... but where's the fun in that? i'm not doing this to race with other bikes, i'm doing it for myself, for my own perverse kind of enjoyment which, next to riding, includes the part of thinking about modifications and building things with my own hands. yes i could buy a few playstations, crates of beer and whatever for the money but chose to spend it on pieces of steel. doctor says they're better for my liver anyway

but you are right: if time and money are a concern then it's better to stick to a stock setup with minor tweaks, and tune it really well. i liked mine as a well running stocker, and i think i'll like this incarnation even more.

strynboen · « **Reply #239 on:** July 05, 2015, 12:51:56 PM »

yes

..you have a point..
and you have a vision of make a 550 as good as it can..so it can do more jobs/types of rides..overtaking at heighvay needs all power you can get..to make a safe ride

..i have many bikes..and have one for all rides..cbx 1000 for hurry..400 four for small slow rides..and 550 for all between.and a Suzuki ..vhen the Hondas dont funktion.and i feel the lack of power in both the small bikes..
.someday i..jump in ..and dropp the stock idea..i think..on the right bike,,, at the right time...but for the bikes i have now.they are just too good for big mods

flatlander · « **Reply #240 on:** July 05, 2015, 02:08:55 PM »

you have a nice collection there! i don't have that many, this one will have to do pretty much everything.
my neighbour has a 400-4 that i sometimes ride. i actually like it although i agree, for longer trips some more power would help. don't know why but historically i seem to be drawn towards smaller and lighter bikes...

i've got this 550 over 2 years ago, used it a lot and really made friends with it. i only started pouring this much time and money into it because i got to know it, and know it's a keeper. it's very well preserved and well running. i like the format, it's great for fast touring on smaller roads which is what i prefer. don't need much more top speed, on an unfaired bike i won't go that fast that long anyway. but making it quicker and overall stronger, while keeping it reliable and long lived - even the thought of it just makes me smile!

flatlander · « **Reply #241 on:** July 15, 2015, 01:25:39 PM »

let's have another update - after quite some time!

prelude
as i said, i had my doubts about the cam. to exclude any errors on my part or with my equipment, i brought it to my local shop together with the timing card and just told them to install it. when it was time to pick it up the mechanic just shook his head and said he doesn't know what's going, just can't get it right. he had some numbers noted down on the card - which pretty much matched my previous measurements.

act 1
so i called megacycle and had a good long chat with barbara. she asked me to send my numbers. by fax. because they're stuck in the mid-20th century and don't use email. now who has a fax machine at home? well this being the 21st century i found some internet service through which i could send a fax for free, so that was sorted - phew!

my numbers that i sent in:

Intake:

Open – 27 BTC
Close – 49 ABC
Lift - .275”
Duration - 256

Exhaust:

Open – 77 BBC
Close – 49 ATC
Lift – .275”
Duration - 306

these were measured as the timing card suggests, with 0 lash at .040" lift.
according to the same card, the numbers for the 12600 cam should be:

Intake:

Open – 11 BTC
Close – 50 ABC
Lift - .285”
Duration - 241
Lobe centre - 109.5

Exhaust:

Open – 51 BBC
Close – 10 ATC
Lift – .270”
Duration - 241
Lobe centre - 110.5

that's nowhere close.

act 2
called them again after sending the fax. barbara saw that the numbers were off and passed me on to jim (the owner?) who also agreed that they didn't seem right and that he would replace the cam if it was really wrong. he asked me to measure once more, however, with the following method:

- valve lash set to 1mm (.040”) on in/ex
- degree wheel setup, rotate engine forward until lash starts to take up (tightens)
- put a mark on degree wheel = opening point
- proceed rotating forward until lash starts to take up (loosens)
- mark on degree wheel = closing point
- calculate 1/2 way point between these marks

then send him the numbers and a photo of the degree wheel with the markings. by fax, of course.

act 3
so i went and did this, and here's what i got:

Intake:
Open – 19 BTC
Close – 42 ABC
Duration: 241
Lobe centre: 101.5

Exhaust:
Open – 52 BBC
Close – 12 ATC
Duration: 244
Lobe centre: 110

guess what? exhaust is pretty much spot on, and intake is only slightly different from the timing card.
looks like the cam will be good, after all. it’s still a mystery to me how both i and the shop mechanic came up with such different numbers when measuring with the dial gauge. i can only guess that there is some variation in the cam or in the system that’s being evened out by the more tolerant manual method.

i called jim and gave him these numbers. in his opinion the cam should work well. so that's it, i'll put my doubts aside and give it a go.

epilogue
i shared the whole story with mike who also found it interesting that jim's method would give such better numbers. he suggested to time it again at running clearance.
so when i do this i'll have used three methods and just use the one that gets me closest to the timing card, ignoring the rest? so much for this being an exact science. anyway, i'm glad i'm getting somewhat closer to the truth now

flatlander · « **Reply #242 on:** July 18, 2015, 08:16:23 AM »

mike recommended to time the cam at running clearance, measure at .040". with that, here's what i get:

intake lobe centre: 103
should be 109.5 according to timing card.

exhaust lobe centre: 109.5
should be 110.5 according to timing card.

exhaust is fine, intake looks pretty early.
i could retard the cam about 3 degrees from its current position... that would give 106 IN (3.5 diff to spec) and 106.5 EX (4 diff to spec).

not sure what's better or worse: leave as is, try spread the difference?

flatlander · « **Reply #243 on:** July 19, 2015, 05:32:32 AM »

ok i can see how these are not the most exciting posts... anyway, for the record, this is what i got after 3 degrees retarding:

IN lobe centre: 105.5
EX lobe centre: 106.5

that's both about 4 degrees earlier than the timing card says. but if i change anything further, the numbers will be more uneven again.
i think it's as good as it gets now and i'll leave it at this.

flatlander · « **Reply #244 on:** July 19, 2015, 12:42:20 PM »

so that's the end of these crazy number games: the cam went in.
before buttoning it up i gave it a tiny nudge in advance direction. could be 0.5, 1, or 1.5 degrees - whatever. just to make sure it's rather a tiny bit advanced then retarded, in case of measuring tolerances.

starting to look like something that could run some time soon:

in the meantime i also picked up an agm battery that promptly took the place of that old acid bucket:

Stev-o · « **Reply #245 on:** July 19, 2015, 03:46:13 PM »

Good choice on the battery, I bought one for my Kaw H1, but wish they were black.

flatlander · « **Reply #246 on:** July 20, 2015, 05:05:01 AM »

LOL yes the colour is not exactly subtle! still i prefer it to acid and my local shop had it on the shelf so it came along...
how is your 550 doing, or are you all busy with the kawa these days?

Stev-o · « **Reply #247 on:** July 20, 2015, 02:29:26 PM »

Quote from: flatlander on July 20, 2015, 05:05:01 AM

how is your 550 doing, or are you all busy with the kawa these days?

The 550F is coming along nicely, replaced the carbs and it's running, but has the dreaded fuel leak. Parts ordered. So it'll be done soon.

I have officially started the Kaw H2 resto, I dropped off the cylinders last week for boring. I've also decided to have the engine powder coated. The Kaw triples motor's originally came with no finish and I don't care for that look over time.
I'll be starting a thread soon in "Other Bikes".

flatlander · « **Reply #248 on:** July 20, 2015, 02:37:25 PM »

yes the that fuel leak seems to be part of the initiation rite with these bikes.
on mine, i closed the engine off and set tappets to running clearance today. megacycle prescribes quite bit more than stock: .005" on IN and .006" on EX.
tomorrow the carbs go back on, then the biggest things are done.

start that thread, i'll certainly pop over to have a look. those triples are cool.

flatlander · « **Reply #249 on:** July 21, 2015, 02:47:55 PM »

carbs are back on!

it took some fancy moves, embracing the engine from the front and pulling the carbs tightly onto the manifold rubbers - must be true love, hope nobody was watching

with this the biggest parts are done. the rest is connecting the wires, and adjusting everything.
the nice thing is that with all the openings closed, i'll be able to do this outside the house in the sun.

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Author Topic: 1976 CB550F - making it good, one step at a time (Read 124843 times)