Long Sleeping '79 CBX Restoration

[shiskowd]

This may be a stupid question, but it looks like your engine stand - like the ones I have - is designed to have the engine rotated once mounted. You would not have to build an elaborate bracket to mount it upside down....????

I built the stand bracket to fasten to the two 14mm frame mounting bosses on the back of the engine. Yes, I could easily spin it upside down but you can't separate the cases when they're both fastened. I wasn't thinking that far ahead why I built the bracket. Normally the engine would be centered in the bracket with the lower engine boss where that angle piece attaches. This leaves the bottom case (at the top when upside down) free to separate. Rev II of that bracket will look at bit different.

[shiskowd]

I wouldn't change bearings if they measure good. Your call on the chains, if the tensioners don't have severe cracking or chunks gone, you can re-use them with confidence. If this bike's intended use is a couple of thousand miles per year, it will last forever.

Dave

Appreciate the guidance Dave!

[shiskowd]

Does anyone have a experience or comments on the Forseti gasket kit?

https://www.ebay.ca/itm/HONDA-CBX1000-D ... 2749.l2649

Seemed like a good value and has most all of the bits covered so I ordered and received it in a couple weeks. I had already ordered Vitron valve stem seals from 'mandatory' for the rebuild. After reading Mike Nixon's article 'Seven Sins' post I'm re-thinking the Forseti unless someone can vouch for the quality.

https://motorcycleproject.com/text/sins ... t_pts.html

[shiskowd]

Finally back at this after some vacation. Engine vapor blasting completed and getting ready to paint the cases. The blasting did a great job of cleaning up the corrosion where the paint had eroded.



The valve cover didn't turn out as well as I'd hoped in terms of the finish - a darker grey than I was expecting. There is also some discoloration in the alloy, not sure if that's a stain or in the alloy itself. Shown below is the oil pan that I tested the paint (etching primer w/ Dupli-color Cast Aluminum 1650 Engine Paint) against the raw valve cover. I'm thinking I'll paint the valve cover as well. The paint is a great match to the original engine paint (I have the other engine on the bench) for the cases and valve cover. The vapor blasting did a good job on the cylinders and head where the castings are quite rough in comparison.





Getting ready for case painting. The engine paint I'm using suggests 'curing' at 300F for 2 hours. Is that necessary? I know operating the engine will get it sufficiently hot but it may take months (years?!) before I get to that point.

[bikeymikey748]

Getting ready for case painting. The engine paint I'm using suggests 'curing' at 300F for 2 hours. Is that necessary? I know operating the engine will get it sufficiently hot but it may take months (years?!) before I get to that point.

If you have the opportunity of curing the paint in the oven I would consider it. Sure the paint will cure on the motor when in use, but depending on how long the initial rides are, it will likely take a few heat/cool cycles before the process is completed. Meanwhile, the paint will remain tacky when hot while the front wheel excitedly throws all manner of road crud at it with predictable results

[EMS]

VHT makes an excellent high-temp clear coat, which I have used on several engine covers and parts. I ordered it on-lime from Summit, but I just saw recently, that Autozone sells the whole line.

[shiskowd]

3 very light coats of a self etching primer...



... then 2 light coats and a medium coat over the primer with Dupli-Color SDE-1650 Cast Aluminum.

Then baking in the sun during some unusually warm weather (for these parts) over the weekend.

If you have the opportunity of curing the paint in the oven I would consider it. Sure the paint will cure on the motor when in use, but depending on how long the initial rides are, it will likely take a few heat/cool cycles before the process is completed. Meanwhile, the paint will remain tacky when hot while the front wheel excitedly throws all manner of road crud at it with predictable results

VHT makes an excellent high-temp clear coat, which I have used on several engine covers and parts. I ordered it on-lime from Summit, but I just saw recently, that Autozone sells the whole line.

Dupli-Color labels their paint somewhat different in Canada (VHT is the same company) for some reason. The engine paint I'm using I believe is the same as the 'ceramic' engine paint they offer in the US (similar part number) and dries very hard without any heat curing. After a few days in the sun the coating is very hard - should be able to stand up to the assembly knocking around without too much marking. Pete Rose at Digital Pizza suggested this paint for this reason.

[shiskowd]

I split the cases for the 'B' engine to prep for painting, similar process to the 'A' engine but I may not bother with vapor blasting as the cases aren't nearly as corroded.

Question - had Honda ever used a silicone gasket sealant between the case halves? This is clearly silicone based sealant - still able to stretch/pull the remaining material. I suspect the cases have been apart on this engine.

[daves79x]

Honda never used silicon seal on the case halves, but it is common enough with rebuilds. It appears you have a set of '79 cases that you painted. Just note that the valve cover is an '80-'82 version and you'll need the larger grommets for the hold-down bolts. It may or may not have had the correct ones when you took it apart.

Dave

[shiskowd]

Honda never used silicon seal on the case halves, but it is common enough with rebuilds. It appears you have a set of '79 cases that you painted. Just note that the valve cover is an '80-'82 version and you'll need the larger grommets for the hold-down bolts. It may or may not have had the correct ones when you took it apart.

Thanks Dave - that would account for the stack of washers that were under the bolts for the valve cover. I have the proper '79 valve cover on the other engine that I'll clean up and paint to keep the '79 whole. Good catch, thanks.

[NobleHops]

Pardon me if I chime in. I don't like to criticize somebody else' work but that is not good vapor blast work. We very commonly vapor blast valve covers and use them as is - they look fantastic. If I had to guess I'd say whoever did that work was using AOX in their slurry and the glass bead was worn out.

A bit of streakiness in the metal is in fact normal, but it's some of the nicest alloy on the engine and should look great bare and vapor blasted.

20190502_174159.jpg

[shiskowd]

Pardon me if I chime in. I don't like to criticize somebody else' work but that is not good vapor blast work. We very commonly vapor blast valve covers and use them as is - they look fantastic. If I had to guess I'd say whoever did that work was using AOX in their slurry and the glass bead was worn out.

A bit of streakiness in the metal is in fact normal, but it's some of the nicest alloy on the engine and should look great bare and vapor blasted.

I'm questioning the same myself Nils... I've had it done previously (older Moto Guzzi) and the results were much better. I'll see if I can find another local outfit for the basting other pieces.

[shiskowd]

Paint do over...

Before I painted the one set of engine cases I inquired of Dupli-color if their self etching primer would work under their high temp engine paints that they sell in Canada (different than the US products) as I couldn't find a matching primer anywhere. I only got a reply back AFTER I painted the first set of engine cases and they strongly suggested not to use their self etching primer as it will blister at 250F. They also wrote they don't sell an engine primer in Canada and suggested I find another manufacture. I understand the oil temp in these engines can approach 300F so I tested the oil pan that I had painted in a small oven at 300F - blistered straight away.

All the on-line US retailers won't ship the US Dupli-color engine paints (including primer) to Canada but I managed to find an ebay retailer that didn't seem to care. Stripped all the paint off the first engine and prep'd the 2nd engine. Used the US product high temp primer and cast aluminum paint.





Why am I painting two engine cases? I'm undecided which of the two frames I'll restore for this first project and wanted to use the near matching engine case serial number. The window of continued warm weather is quickly closing in these parts and I wanted to paint either before too much longer. The 'A' bike, as I have identified, is an early Z model with the engine serial number on the top of the engine case, the 'B' engine has the serial number on the far right side of the case where it continued to be located through the balance of all future CBX production. Comparing the two engine cases, the later version cleaned up a number of bosses used in the molding process and straightened out the flange which the cylinders seat.

Early Z


Later Z


Nils - I also stripped the valve cover and will seek out a different vapor blaster to a better finish. I could brighten it significantly with a fine brass wire brush so it can indeed look better!

I tore down each frame and will take a closer look in the next days to see if there are any defects that would suggest one frame over the other. Right now I'm leaning to use the 'B' parts bike frame w/ later engine case.

Are there areas that I should be looking more carefully for frame/weld cracks?

[steve murdoch icoa #5322]

Too bad about all the extra work with the engine paint.
Assuming they are extra harsh chemicals in the primer is the reason why they won't sell in Canada or is it just not a big enough market?

[daves79x]

Sorry for your paint troubles. I've painted several whole cases and many valve covers and other engine parts with Dupli-color paint. Never used primer and they all look good up to 10-12 years later. Just strip and clean everything again and paint it. Don't agonize over the valve cover either, just paint it. They were painted the same as the rest of the engine from the factory.

Dave