Topic: 1977 CB550 K cafe racer build

[fasturd]

Joe,

What size lesters did you end up using?

Did you ever verify if the 750 wheels fit the 550?

I am pondering my next project...

[Zaipai]

First let me apologize for hijacking your thread Joe, second my bike will be more highway driving and less around town since our town is only a few miles wide and is surrounded by lots of nothing.. So if I go to my friends house for example, most of it is 45 to 55mph and many police to enforce that. So that said, I may just leave it as is. Better fuel economy (especially with the tank I have) is a good thing and keeping rev's down would be a good thing. I will still give it some thought, however I am thinking retro rocket brings a good point for the way I would be driving this bike. Rapid starts are just not that important to me for the few times I would do that.

.: Scott :.

[Retro Rocket]

First let me apologize for hijacking your thread Joe, second my bike will be more highway driving and less around town since our town is only a few miles wide and is surrounded by lots of nothing.. So if I go to my friends house for example, most of it is 45 to 55mph and many police to enforce that. So that said, I may just leave it as is. Better fuel economy (especially with the tank I have) is a good thing and keeping rev's down would be a good thing. I will still give it some thought, however I am thinking retro rocket brings a good point for the way I would be driving this bike. Rapid starts are just not that important to me for the few times I would do that.

.: Scott :.

Most of the Honda's i have had have had big bore kits and i do a mix of round town and highway riding, i usually raise my gearing slightly by reducing the amount of teeth on the rear sprocket by a couple of teeth, it just takes a bit of strain off the engine when cruising for hours at a time and it never bothered me around town.

Mick

[Zaipai]

First let me apologize for hijacking your thread Joe, second my bike will be more highway driving and less around town since our town is only a few miles wide and is surrounded by lots of nothing.. So if I go to my friends house for example, most of it is 45 to 55mph and many police to enforce that. So that said, I may just leave it as is. Better fuel economy (especially with the tank I have) is a good thing and keeping rev's down would be a good thing. I will still give it some thought, however I am thinking retro rocket brings a good point for the way I would be driving this bike. Rapid starts are just not that important to me for the few times I would do that.

.: Scott :.

Most of the Honda's i have had have had big bore kits and i do a mix of round town and highway riding, i usually raise my gearing slightly by reducing the amount of teeth on the rear sprocket by a couple of teeth, it just takes a bit of strain off the engine when cruising for hours at a time and it never bothered me around town.

Mick

So it drops the RPM's at higher speeds?

.: Scott :.

[Retro Rocket]

Exactly.....

Mick

[traveler]

Yeah...makes sense Mick....but you gotta remember, I have a stock 550 versus the big bore 750 mill.

On the Lesters....750 fitment works, but requries some modifications....I covered it a few pages back but will briefly cover it again.

Rear wheel.....requries 750 cush drive and factory 750 spacer on the cush drive side.  The brake side....550 brake plates are a direct fit, and the part number for the 550 brake plate is actually listed as a suitable replacement on most K3-K6 CB750's (I cross referenced on Western Hills Honda's site)

Also on the brake plate side, use the 550 spacer.....the axle works perfect.

Front wheel....the "beautification" chrome plate that goes over the wheel before the speedo pickup won't work.....so you have to skip it.....also had to carefully notch two flat sides on the wheel to allow the speedo pickup plate to work....otherwise it's a straight fit.  My flats were obtained by CAREFULLY using a die grinder on the wheel to allow the pickup to sit flush.

Again, go back a few pages to see more about it....but if you are willing to do a little modification work, and have the 750 cush drive side bits....it's a real easy swap.......also the 750 rear wheel has 3 bearings instead of 2 and more cush drive rubbers.....so it is overkill/overbuilt when used on a 550 which is a good thing!

Lastly, 550 sprockets are alot smaller than a 750, so give Sprocket Specialists a call....they hooked me up with an aluminum 37 tooth sprocket which is REALLY nice! (550 sprockets won't fit...need a 750 specific sprocket)

~Joe

[traveler]

Well, I'm back from my vacation, and my 115 main jets came in.  So, I installed them.

I changed the jets with the carbs still on the bike.  As a consequence, I must have bumped the #4 carb float a bit much, as that carb now overflows!

Anyway, the bike starts right up and idles great!  Runs fine, but at 4,500 to 5,000 RPM it stumbles.

I was able to find out....that at 60mph in 5th gear my RPM's are at 5,100 RPM.  So that is what 15/37 gear ratio gets you on a 550.

So, It appears that 115 mains weren't enough fuel.  I parked the bike in the garage, started it, rev it up and killed the engine.....pulled a plug and she is lean....also the pipes have turned a gold glow....so that's a lean condition.


Just have to figure out if 120's would be enough.

also have NGK BR7EA plugs

P.S.  Stock front springs are way too spongy and soft....need to get some progressives....and maybe some 750 preload slugs if necessary to fix that problem....oh, and some heavy oil in put in there!

Rear drum brakes look cool, but suck in the braking dept.

~Joe

[Zaipai]

All good info Joe, I would think there is some way to figure out the main Jets with out buying each setup up.

At 60mph at 5k seems a bit high does it not? One of the roads I would be riding this bike on is an interstate with a speed limit of 65 and if I want to keep up with traffic I need to be at 70 ~ 75, seems if I drop some teeth I would be in the 6k plus range.. I am gonna have to think about that some.

Drum brakes suck if you are braking hard, I don't ride it that hard so I am fine with the drums however if I ever get the chance to swap them out for discs you bet I would in second.

I have 8ea plugs seems to work better for my bike I had the 7ea's and it was not running very well at lower speeds..

I know what you mean about the front forks, just be careful is easy to over do it.

I hope you had a great vacation.. Enjoy this weekend man..

.: Scott :.

[traveler]

Thanks Scott.

BTW.....20,000+ views on this thread!

all this over an old 550K with some mods done.

Appreciate the support thus far, and hope some of my work is of value.  If so, then it has been worth it.

~Joe

[Zaipai]

Joe that is what I have been saying. Your thread has move value then you realize..

Gratz, on the views..


.: Scott :.

[cracker]

BTW...You got my vote on BOTM. For what it's worth, the vote's as much for the documentation you've put into this build...as it is for the shear beauty of the bike. Best Wishes!

[traveler]

Thanks.

~Joe

[Zaipai]

Joe.. (ignore my bad skills in Gimp..)

Just thinking dual disks is called for..

.: Scott :.

[traveler]

Well, I just ordered some Progressive fork springs (#11-1106).

Just need to figure out:

What type of oil to use....10wt?  I've read 15W is too thick.

How much per tube.  Since I am just going to drain and refill....any ideas?

I'm thinking about using some type of caulk in a thin bead around my intake boots to ensure no air leaks......I'm talking about a THIN bead.....I'm going to have to pull the carbs again to re-adjust the #4 float, and then isntall the new intake rubber seals, and will do the sealing then.

comments?

~Joe

[Zaipai]

Sweet.. I would stick with the 10W and go with around 5.4oz in each, I know the springs will be stiffer but I don't think that has much bearing on the oil and the amount of oil. However that is an uneducated guess on my part.

As for the air leaks, don't bother. The pods are letting in so much air that putting any sealant on them is like putting out a forest fire with a garden hose. You could try (just to see) wrapping the pods with some filter material and see if it runs richer then. That is why I went with the pods I have, the foam is more restrictive then the pods I was using (much like what you have).

Just some thoughts..

.: Scott :.

[tweakin]

I love building these bikes but hate messing around with the old carbs.  After building multiple harley motors I have a new appreciation for the ease of EFI when doing motor mods.  I have completely rebuilt my 77 750f carbs but I am seriously thinking about shelling out the extra $$ for some 29 CR's to save me some headache when tuning the 836 with cam.

Bike looks great Joe, hope you had a great vacation.

[traveler]

Get this.....the factory manual says to use 10W30 oil in the forks!  5.4 oz...or a "hair under" 3/4 cup each tube!  too easy!  Bring on the springs!

hell, I can do that!

Oh!.....And can you beleive, when I pulled my dipstick, which had been in the "ok" area before I started riding her 2 days ago was now dry/empty?  No drips.....I guess running her lean, i.e. HOT made her burn oil!  Needless to say, I am BEYOND glad I didn't hurt the motor!

~Joe

[Zaipai]

Yup, 10W30 however don't use the Sythetic oil, I can't remember why however I was advised against it. I just put some fresh oil in mine, big difference. I did 5.4 however I think I should go 6, so going to ride it a bit and then see. Funny how much you can beat these old motors and they just keep going..

.: Scott :.

[fasturd]

Air cooled motors will just "use" oil when ridden hard and long. On one of the iron butts I did I used my modded CB900F. It was a 48 hour 2000 mile minimum event. On day two about 350 miles from home the oil light came on. I stopped for gas and sure enough it was 2.5 qts low on about a 3.9 capacity... Started it up and the light was off so away we went. Prior to the first stop we had been running pretty much 80-90 mph after the fill we needed to run right around 100 to get where we needed to go. Needless to say oil consumption went way up. The oil light came on again about 300 miles after the refill... If we stopped we would be disqualified as we would not make the cutoff. So I kept the throttle twisted for another 60 miles with the light making me feel more and more guilty. We pull in to the finish and get the time stamp with about 2 minutes to spare before being DQ'd. After checking in and turning in all the paper work and waiting for the results I decide to check the oil. Of course nothing on the dip stick, 2 qts in nothing, 3 qts still nothing, took the whole 4th qt to get it on the dip stick. There was NO oil just lady luck and some amazing protective sludge. I had been using Honda oil in it for years. Anyway I hit the starter and it fired right up. No smoking, never had a problem with that bike and sold it to a guy who loved it. And to top off the good luck I took 3rd place with 2400+ miles in those 48 hours with stops and required recipts. I ran naked on a then 20 year old bike. NO GPS no Radar detector and you should have see the bikes in the class, Hayabusas that looked like NASA built them. VFRs with special seats and all kinds of wires and lights...LOL. It was worth the guilt I felt for flogging that poor engine. Just to see the looks on their faces when they saw what took 3rd place!

So moral of the story? Fill that sucker back up and RIDE it! 

[Retro Rocket]

I wouldn't say thats the norm Fasturd, i have done several 1000mile plus trips at high speed on all types of road bikes and NEVER had that problem at all. I have done 8 hour trips down the New England highway from Brisbane to Sydney on a 750/4 , and for those that know this route it means spending quite a bit of time over the ton to make it possible. My 900F was a good bike with a great engine {i know plenty that weren't} and it never suffered this problem either, actually at 100mph it was hardly working......

Mick

[traveler]

Well, now that this BOTM stuff is over and I came in last place, I can go back to just doing my thing.....no love for cafe's I guess.

Appreciate all those that came out and supported my bike though.

~Joe

[Retro Rocket]

I would be proud just to have been nominated amongst those 4 bikes, remember Joe, you built it for yourself.....no one else...

Mick

[Zaipai]

Sorry Joe, Its odd.. Seems there was only one picture of Terry's and it exceeded Photobuckets views, so how did people vote for a bike they could not see? I suppose they saw it at one point like I am sure I did, but still you and the others had more detailed photo's and more info then Terry did, not to take away from Terry's build I am sure its wonderful.. Just strikes me as odd..

Anyway.. Keep an eye on the oil man.. You are BoTM winner in my eye's..

.: Scott :.

[shane]

Well, now that this BOTM stuff is over and I came in last place, I can go back to just doing my thing.....no love for cafe's I guess.

Appreciate all those that came out and supported my bike though.

~Joe

I think it could be the Lesters... They're a love/hate type of thing.

Rad bike nonetheless, you built it for you not everyone else, that's what really matters.

[traveler]

I really appreciate the support, guys.

Time to move on.

Waiting on my progressive fork springs.....picked up some 10W40 Valvoline motorcycle oil, and am waiting on a new engine oil filter off of eBay.  I'm going to use 10W30 Pennzoil in the forks, and again, I'm waiting on the O-Rings for the intake runners from Western Hills Honda.  Probably should get some new clamps for the boots.....

Getting tired of spending money guys, in all honesty....I'm ready to just ride it now, but I have to do things right.

~Joe