Topic: 1976 CB500/550 Project "Squirrel"

[bwaller]

I've mounted a magnetic base on a frame rail and indicate on the clutch center anywhere with the circlip in place with no shims. Just grab the center and work it "in & out" watching the indicator. You can also get a read by inserting a feeler gauge between the circlip and the hub.

Honda asks for 0.004" max otherwise add a shim. A little extra clearance is better than not enough.

[riverfever]

Are you sure its the clutch slipping or a cable that needs adjusting? Is the cam on the left in good condition?

I do believe it's the clutch. It's only done this a few times but in third gear while accelerating the rpm's will rapidly and momentarily increase while speed remains constant. Just figured I'd look into it as soon as the snow starts to stick. Which should be tomorrow or the next day.

[RAFster122s]

Price the parts on South Sound Honda in Olympia Washington...excellent discount and reasonable shipping charges. Worth considering if you are shopping Honda parts

[riverfever]

Need some guidance. Within the last several hundred miles I've started to get a healthy oil leak from the top end. Back in the spring I had a leak in this area and when I went to redo the pucks I found the head fasteners were very loose on the left side of the motor. I torqued them to spec again and things were good over the summer. Now I'm back in square one.

I suppose the best course of action would be to remove the rocker cover again (after ordering more pucks) and see if those fasteners are loose again. I did not put anything on the studs/nuts like Loctite and didn't think I was supposed to. Should I have done this? I know for certain that when I did the top end I torqued those fasteners to spec so they DID back off the first time. If they did it again, I'm going to get another torque wrench and verify it against mine and see if mine's accurate. I guess if I find that the head fasteners did NOT back off again then I may need to look at doing head and possibly base gaskets again along with all of the o-rings just to be sure?? What would you all do? Both head and base gaskets were Honda and I put a very light coat of Hylomar on both.

[RAFster122s]

Can you clean the head and cylinder and head and cover interface.  I think it is the cover leaking if I understand you correctly.   But, once you have cleaned it get some foot powder , white of course, spray this on the head interface to cylinders and cover.  Take it for a short hop and a good strong light will show you where the oil is leaking. If it is not showing, then longer will reveal it.  Have you checked the o-rings on the tappet covers and that the cover is evenly torqued.  Be careful, you can over torque by hand and that will distort the seal sometimes causing a leak unless the seal is very spongy.  You could even sheer a bolt but that should require you to use some muscle on it.  A very small torque wrench doing inch pounds that is 1/4" drive will be appropriate.
It is what? 6 ft lbs or at most 8 ft lbs  that is tiny bit of movement once it begins to tighten.  Isn't it 16 ft lbs is equal to turning the fastener after it stops equal to one flat of the hex headed bolt or nut for a machine screw?  So, if you put those guns to work it is going  to overtorque the fastener.                                                                                                                           

[RAFster122s]

If it was a MLS gasket Hylomar or any other stuff other than a light coat of the copper spray adhesive, but I do not like to use that.  The MLS gaskets have a special construction and for proper sealing they should be applied to clean metal sufaces on the head and cylinders.  You would use a tiny bit of hylomar designed for high temp around the orings and the gasket.  The cb750 have oil orifice ports that can be  blocked/clogged by rtv or hylomar. I have not torn my head off to know if the 550 also has those oil orifice ports in the dowel like setup... I have not went below the top cover before I ran into motor damage from the eccentric wear. The rebuild halted until I can find  a 77-78 cover I can afford and have the head checked for flatness, money for cam chain and tensioners and full Vesrah gasket set. It will go back together with 605 kit.

[riverfever]

Things are a complete mess right now. Oil is all over the fins (mostly on the cylinders) but also one or two fins higher than where the head meets the cylinders. It’s on the exposed areas of the front of the air box, leaked all down to the bottom of the alternator, and blown clear back to the side covers and the frame back there. Seems like a significant leak and I’m sure it’s spewing at higher rpms. There was not oil on the side covers (some on the fins) today and I rode it about 40 miles just burning what was left in the tank so I could get it ready for winter. The tappet covers look fine and I don’t see oil from them, the rocker cover, or the end caps. I’m guessing it’s got to be the pucks or the head gasket. Tomorrow I will use engine degreaser and get things cleaned up and then put some baby powder at the base of the rocker cover and also at the head and cylinder (that’s where things look the worst).

Thanks for the input David. This is frustrating.

[riverfever]

Question...cylinders and head were both decked. I did NOT take anything off the locating pins. Wonder if this is causing the head gasket to not do it's job as well as the o-rings? If those things are decked, do you need to remove a bit from the pins and, how do you know how much to take off?

[calj737]

Question...cylinders and head were both decked. I did NOT take anything off the locating pins. Wonder if this is causing the head gasket to not do it's job as well as the o-rings? If those things are decked, do you need to remove a bit from the pins and, how do you know how much to take off?

Remove the head, remove the gasket, place the head on the cylinders. See any daylight? If so, the dowels are holding the head away from the cylinders. BUT, if that were the case, it would have leaked from the first moment you fired it.

[riverfever]

Today I cleaned up the motor as best as possible and then put some baby powder around the bottom of the cylinders, where the head meets the cylinders, and around the area where the rocker cover meets the head. I went out for about 5 miles and stopped. I saw absolutely nothing where the head gasket is or the base gasket. I did see quite a bit of oil coming from number three intake inspection cover. This appeared to be running down and getting to where the cam chain tensioner bolt exits the cylinders (this area was very wet). I saw a lot of wet spots where the rocker cover meets the head (all the way around) as well. I rode for about another 20 minutes or so and then brought it back home. Still nothing from the head or base gaskets. I honestly believe the oil was running down (from a few inspection covers and the rocker cover) and getting blown to the back of the cylinders where it's pooling up near the starter and then as it moves outward its getting blown back to the side covers or running down to the bottom of the alternator.

I'm sure that I am guilty of having things like those inspection covers too tight (recall one of those broke a few months ago) as well as the rocker cover. David, you mentioned this and how it may be causing the o-rings and gasket to actually not seal properly. Certainly could also be pucks but I doubt it. I used OEM pucks and a very light layer of Hylomar. Tomorrow I'll pull the exhaust and clean everything real well with degreaser. Should I order new inspection cover o-rings and rocker cover gasket and be less aggressive with tightening? Still wonder why this happened all of a sudden? I looked at the o-ring for inspection cover three and it seemed fine. Thanks for any input.

[RAFster122s]

The tappet covers, inspection covers, orings are pricey from Honda. With worn orings there they will leak.

Once oil starts flowing is what you are trying to catch.  Capillary action will cause the oil to wick around the any seam of a gasket between head to the cylinders or to the rocker/cam cover.  Once it starts flowing it will blow and drip and run to areas where it is not leaking from.  With as much oil as you are reporting you are not catching the start.

Cross threaded tappet covers will cause them to break, or cross threading. The orings are not submerged but slosh or splattered and if the oring is not sealing it wicks out...  it is good there is a lot of oil... you have sufficient oiling to the head.

The cam cover gasket can distort if overtightened and cause leaks.  Usually you don't cause leaks on the tappet covers, you can make them hard to remove and possibly cause them to break. When they are hard they can start leaking.

On a car a cork valve cover gasket is easy to over torque one of the screws causing a leak. Provided the cover is not deformed...easy to do on sheet metal covers.  Normally cast covers are not at risk of deformation as easily.

Fix the small stuff, then work your way into the next one...  once it starts leaking it can be tough to keep it from appearing to be leaking somewhere else.  Want to deal with more difficult to isolate leaks then you want to deal with a leaky roof.

[riverfever]

Today I got a lot of the bike detailed. I still have a bit to finish but things are much better. I pulled the number three intake tappet inspection cover and even though I replaced the o rings during the top end rebuild, it looked flat. I also noticed a very small scratch in the sealing surface of the rocker cover (where the o ring for the inspection cover would sit). It's very small but I'm wondering if I should gently sand it down so it's even? Could be from a razor blade or screwdriver when I was scraping paint off the sealing surface or it could have been there before. I also found new tappet cover o rings and will replace them all. I will also pull the rocker cover and have a look at the gasket as well as the metal surfaces all the way around and see what they look like. I have a new gasket on the way just in case.

[riverfever]

Small update. I found a hairline crack in the top of the rocker cover and that's where the oil was coming from. Since I had just put the top all back together, I decided to try JB Weld. It sat up for a week and today I started the bike to drain the carbs and get her ready to for a long winter nap. Still leaking a bit from the same spot. Squirrel will sit now for a while. I may pull the rockers off the new 77/78 cover I have and get it blasted and powder coated so that I can swap it out at some point this winter.

[SOHC4 Cafe Racer Fan]

Small update. I found a hairline crack in the top of the rocker cover and that's where the oil was coming from. Since I had just put the top all back together, I decided to try JB Weld. It sat up for a week and today I started the bike to drain the carbs and get her ready to for a long winter nap. Still leaking a bit from the same spot. Squirrel will sit now for a while. I may pull the rockers off the new 77/78 cover I have and get it blasted and powder coated so that I can swap it out at some point this winter.

After you get back from The 1 Moto Show!

[riverfever]

^ That would be cool.

It would be nice to get the new rocker cover installed this winter but I’ll have to have someone finish it. With the rockers removed, can the cover be sand blasted or is that not a good idea? What would the preferred method be? Also...I have a friend that says he can Cerakote the intake. Would that be okay or should it be powdercoat/paint? Thanks.

[Stev-o]

^ That would be cool.

It would be nice to get the new rocker cover installed this winter but I’ll have to have someone finish it. With the rockers removed, can the cover be sand blasted or is that not a good idea? What would the preferred method be? Also...I have a friend that says he can Cerakote the intake. Would that be okay or should it be powdercoat/paint? Thanks.

Blasting it is fine, but use another media other than sand.  I dont know that much about Ceracote but I dont see a problem. Maybe do the same to the head cover.

You dont want to polish it?

[SOHC4 Cafe Racer Fan]

I'd send it to Nils for blasting.

[riverfever]

First off...thank you for taking the time to pull the Corvette over and respond to this question. Yes...glass instead of sand. Knew there was something particular. I’m coming off almost two days of no sleep so I’m not thinking clearly. And I’m probably wrongfully referring to the part as the rocker cover instead of the head cover but I believe we mean the same thing.

I don’t know much about Cerakote either other than that it’s used on guns which makes sense because my buddy is a gun guy. Not sure if it comes in colors. I do like the color of the current head cover but I’d rather get it done soon and if that’s the case then it’ll be a satin black which will match the head.

And no I do not want to polish that thing. I redid several pieces to freshen them up a bit and will do a few new things this winter but that won’t be one of them.

[riverfever]

Hmmm. That is an idea Don. Would I get the cover cleared then?

[SOHC4 Cafe Racer Fan]

Hmmm. That is an idea Don. Would I get the cover cleared then?

I would clear powdercoat it, only because you are prone to get some gas dripping from the carbs that could stain the cover.  With the PC, it will clean off easy.

[Stev-o]

First off...thank you for taking the time to pull the Corvette over and respond to this question.

Ha!   Actually was driving it today, a little cool out [45*] with the top down!

Ok, just looked it up. CeraCoat is basicly powdercoat but with ceramic and there are differant colors. Ceramic is typically more expensive than powdercoat but is much more heat resistant. I'm sure Call will be along to fill us in.

[calj737]

Send it to Chewy and have him polish it for you...  Or Nils for vaping and clear powder as Don suggested.

[riverfever]

Obviously I want things to look good but I am worried about the intake being vapor blasted and being a different finish than anything else. I like the idea of the cover being a satin black to match the jugs and head. But...Chewy could also Work his magic and the polished bits would go together.

[calj737]

...and HE needs the side work... Go ahead, help a Brother out, River-

[joeyvans]

My vote is for a Chewy polish.


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