Topic: CB 750 Project 1 - Rides Well but a few tweaks needed

[edwardmorris]

If you're pondering the idea of clear over engine cases, I'd say be cautious and do some digging first. Too many horror stories about clears turning brown, I've yet to find a high temp clear that actually works as well as the one Honda used. If yours is a K2, then the engine was painted silver from the factory anyway so you might wanna consider that instead. I had this dilemma and started a thread somewhere, general advice was to stay away from clear for engine parts and go with silver as it came from the factory.

[timbo750]

If you're pondering the idea of clear over engine cases, I'd say be cautious and do some digging first. Too many horror stories about clears turning brown, I've yet to find a high temp clear that actually works as well as the one Honda used. If yours is a K2, then the engine was painted silver from the factory anyway so you might wanna consider that instead. I had this dilemma and started a thread somewhere, general advice was to stay away from clear for engine parts and go with silver as it came from the factory.

It was suggested to leave the covers bare and just keep them clean, I have been told that apparently the clear that doesn't go yellow is POR. I was definately going to PC the case, block and head. Its just thst the parts look so good after the wet blasting it would be a shame to cover them up.

Project 1 CB750 - http//forums.sohc4.net/index.php?topic=126864

[timbo750]

The next thing I am not quite sure about pulling apart is the carb backing plate. I started to do it by loosening all the bolts and screws but the shaft would not remove, then found out about the pin that holds it in place. Now I am not so keen unless I absolutely have too.

How do I determine if the assembly needs pulling apart, there seems to be no freeplay on the shaft but it does move end to end a bit, more than I would of expected but I am not sure how this will affect the reliability of smooth carb operation.

[Stev-o]

If you're pondering the idea of clear over engine cases, I'd say be cautious and do some digging first. Too many horror stories about clears turning brown, I've yet to find a high temp clear that actually works as well as the one Honda used. If yours is a K2, then the engine was painted silver from the factory anyway so you might wanna consider that instead. I had this dilemma and started a thread somewhere, general advice was to stay away from clear for engine parts and go with silver as it came from the factory.

It was suggested to leave the covers bare and just keep them clean, I have been told that apparently the clear that doesn't go yellow is POR. I was definately going to PC the case, block and head. Its just thst the parts look so good after the wet blasting it would be a shame to cover them up.

Project 1 CB750 - http//forums.sohc4.net/index.php?topic=126864

Found you Timbo.  +1 leave the side covers bare and just polish 2-3 times a year

[timbo750]

Latest delivery was SOHC T-shirt and happy to wear the branding but not overall happy with quality of printing. It is some blurred, not centred on the front and after one was is showing signs of wear.

[timbo750]

Well I have hit a milestone finally, the frame and some other parts have come back from the powder coaters. Really happy with the finish on the frame and frame parts, had a drama though with the brake capiler parts. There were bad marks where the they had been hung and also the didn't tape/plug the brake line and bleed screw holes. But he is going the redo them, they will be sent of the get stripped and then redone.

[SOHC4 Cafe Racer Fan]

When you pay good money for services like powdercoating, you should get exactly what you wanted.

[Jerilee]

Looking great, cant wait to get there with my frame! Get some pics of the calipers when they come back. Good luck with assembly.

Did you go with a gloss black or matte?

[Stev-o]

Frame looks great.   

[timbo750]

I was looking at the frame yesterday and noticed a rust hole. It would of shown up after the PC blasted the frame and they didn't say anything, its a pain that I have to fix it but the bastard could of said something. I now have to strip back the fresh coating and come up with a solution to fix it.

The rust hole is on the side of the gusset that the rear of the engine bolts to. I am thinking of cutting a piece that fits over and around the existing plate as it will be easier than fitting a piece back in the same spot. I know it will be visible when it is all finished but only the trained eye will notice it is there.

[edwardmorris]

Sorry to hear timbo, but it looks like its just the gusseting plate? Or did you find some damage in the tubing too? The PC guy sure isn't blind, why didn't he tell you?

[timbo750]

On a brighter note, i now finally have all the parts to reassemble my forks. Got the lowers from Bill last week and took them to the chrome shop to get stripped, as they were not busy they had them done quick and i got them to polish to a brushed/satin finish as well.

Got my progressive springs from DCC along with a new brake master and some other bits.

The engine is finally making some head way and I have been doing the porting myself at my mates workshop. Unfortunately one of the studs broke of while trying to remove so that now need to machined out and a new thread inserted.

The other thing I started is a new seat base, the only one i have is rusted too bad and the prices here are ridiculous and postage too much from overseas. So I am trying to make it as low profile as I can but still two up, will post pictures when I can.

[timbo750]

Sorry to hear timbo, but it looks like its just the gusseting plate? Or did you find some damage in the tubing too? The PC guy sure isn't blind, why didn't he tell you?

The Tube looks to be ok, but when something rusts from the inside out you never really know. I am unsure of the structural/strength requirements of this gusset so i do not want to take any shortcuts.
I do know that the PC gut had truoble with staff when my frame was getting done and had to replace staff due to their work, so I would say that the owner didn't even see the frame so I will talk to him on monday and see what he says.

[timbo750]

Cal. Thanks I didn't know that it could be touched up, thats quite a relief.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864

[edwardmorris]

If you're worried about rusting from inside out, you might want to consider Eastwood's internal frame coating.

This thread terrified me

http://forums.sohc4.net/index.php?topic=132523.0

So eventually I went through it all and coated it from the inside, some details here

http://forums.sohc4.net/index.php?topic=126735.75

[timbo750]

Got the frame fixed, the PC guy offered to fix the rust hole he blasted it and repaired the hole and patched the PC, I was impressed that he offered to do it for free. Then I went pick it up he complained about the money and time he lost fixing the issue, I found this very strange as it was something he offered to do, all I originally asked him to do was patch the PC after I fixed the rust hole. No future business going his way.

I did notice that there are insufficient drain holes in the frame so I will get some drilled and then before I go any further I am going to treat the inside of the frame with fish oil.

So I now have all the parts to finally get the frame rolling, the upper triple needs a clean up but I can do that while the frame is soaking.

Also the engine is finally making some head way, the head is ported, did that myself at my mates workshop. the ports really are a #$%* shape as standard, they do have quite a flow restriction around the valve boss. The machining work should start this week but some of threads are stuffed for the head studs so they are all getting fixed.

So it might be still a couple of weeks away but I will soon have the reassembly started.

[Retro Rocket]

Tim, you mentioned in another thread that you can't get the primary chain tensioner, cycle X have the stock and better than stock tensioners for sale on their site...  Check this page out mate...

http://www.cyclexchange.net/Engine%20Parts%20Lower%20End.htm

[timbo750]

Retro, the oem unit is as the web site says 'out of stock forever' and the other unit is on an exchange basis which works out to be costly for anyone out of the states.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864

[SOHC4 Cafe Racer Fan]

Retro, the oem unit is as the web site says 'out of stock forever' and the other unit is on an exchange basis which works out to be costly for anyone out of the states.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864

Every now and again, Cycle X will sell you an improved tensioner without the exchange.

[timbo750]

I have actually got two old ones. One is worn too much and the other is ok. My post was to help FB with an idea of what help his business grow, he clearly provides a quality product and if I can help him then it will help us all in then end.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864

[Retro Rocket]

Retro, the oem unit is as the web site says 'out of stock forever' and the other unit is on an exchange basis which works out to be costly for anyone out of the states.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864

I got mine without exchange....   I'm about to buy an adjustable one and another improved one...
I have 3 old ones. If you have any problems see if you can get a member that has one to send it to cyclex for you, i've done similar things with members here....

[Terry in Australia]

Subscribed.

[timbo750]

Got the covers back from the polishes today. Will post photos when I get time and space to take them out of the box, they look quite good considering what they where like.

[MRieck]

Fork case = sliders (or lowers)

F2 forks will fit your triple, both stanchions are 35mm. But... you may run into trouble if you plan to keep your spoked wheels, as F2's were fitted with comstars. May need some ingenuity with rotor size/spacing, and spindle spacers will also be different. I'm sure it's been done though. I think you'll find a lot of people opt for a GL1000 front end.

I have done it.

[MRieck]

Honda Man - in reply, where all the bearings "extra clearance" I am thinking I may have normal for them all however I didn't ask when ordering so I don't really know.

With the final drive both original and the purchased set have a double row bearing and the set I purchased had excellent bearings and so I ma not changing them. this said though I think all the bushings are bronze from memory - I will check on that.

I have check the shift drum for anything other than excessive wear, but I got forks with shift drum I purchased so it all should match up there. I will just need to check the pins and holes for slop. the old drum actually rotated freely by hand before I pulled it apart so the holes in the case should be fine.

Once again HM your knowledge is outstanding and always grateful, I have ordered your book but it is very slow coming across the waters.

Some folks used to get the 'extra clearance' bearings for all 4 on the shafts, back in the Production Stock roadracing days of the 1970s. The theory was that they didn't need as much break-in time to release the friction, and since these bikes were often running at very high revs during our bouts, it made some sense. After I've ridden mine so far, though, I am keen with the idea of keeping the tight ones myself, just because the gear wear was so low that I used most of the gears again, changing just a few. The 'new' ones had more inner bushing clearance than the 'old' ones, even now, and none of them had measureable (or even observable) tooth wear toward their outside edges of the teeth. This latter would show up if the shafts were out of alignment for a long time from the twisting loads, and as much time as I spent near (or over) triple-digit speeds in those pre-marriage years, I was dead sure I would see this: sometimes I would be doing whole weeks of 1000-mile days for my vacations, changing oil every night. I see it in the later gearboxes (iron bushings) with far fewer miles, so it seems the bronze ones make a heck of a difference.

Thanks HM, the finally arrived today - took just over a month, I got parts from Dynoman in one week, strange. it would however seem strange that Honda would go backwards with cast bushings instead of the bronze, we may never know why.

15. The bronze bearings inside the tranny gears became cast iron on all the New Factory bikes I saw by 1974. By 1976 they were all cast iron.
18. The expensive "holey" drilled-and-lightened cam sprockets disappeared in favor of solid, as-cast versions.
19. The expensive 1-piece oil rings disappeared and became the cheaper ripple-ring type.

  My 750F has bronze bushings in the gears and that is 1975.
 The early cam sprockets were heavy, sold pieces....the later sprockets had the lightening holes. I just ordered a new OEM sprocket....it has the lightening holes.
 The 1 piece oil rings were dumped by every manufacture of engines as they do not seal as well and produce a lot of friction. They are also clunky, thick heavy pieces. Being cheaper to manufacture has no bearing on their performance. It happens. Ring packs have gotten thinner to reduce friction and improve performance.