Author Topic: 1974 cb750 fun "Spruce Goose" (STEP 2: frame/suspension)  (Read 28376 times)

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Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #50 on: November 30, 2015, 01:51:59 PM »
Quick question on the crankshaft/connecting rod bearings, if all of the current bearings are within spec can i just reorder the same bearings or should i order a few and test each housing to make sure the new ones will be in spec?

Offline Davez134

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #51 on: November 30, 2015, 02:30:34 PM »
If they all are within tolerances using plastigauge, with no signs of visible damage/gouges, then you can just keep them in there (or order same size if you must replace for peace of mind) Ordering different sizes is to compensate for out of spec bearings

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #52 on: November 30, 2015, 03:02:54 PM »
Cool, thanks Dave. Ya they're all within tolerance using plastigage, they have usual wear scuffs but since i will be replacing all the ball bearings, figured i might as well change these bearings aswell.

Offline edwardmorris

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #53 on: November 30, 2015, 03:32:25 PM »
Cool, thanks Dave. Ya they're all within tolerance using plastigage, they have usual wear scuffs but since i will be replacing all the ball bearings, figured i might as well change these bearings aswell.
That's what I thought and did too. New ones of the same spec will still 'feel' nice and tight early on 8)

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #54 on: November 30, 2015, 04:05:04 PM »
Like you said Ed, get it right the first time!

Anyone have any good experiences with a brass wire bit on a dremel? I picked up a few bits but they shoot out all the wire after a few minutes of use... Im really liking the finish of the case from just going over it with brass wire on the drill, but the hard to reach places need the dremel.


Offline Davez134

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #55 on: November 30, 2015, 06:30:15 PM »
I too replaced them for peace of mind. Also, you're not "supposed to" reuse the rod bolts.

Those brass Dremel attachments will not last long, as you have noticed. If anyone in your area offers vapor blasting, look into it!

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #56 on: November 30, 2015, 07:17:34 PM »
Definitely changing the connecting rod bolts before i actually start the engine up, but they did fine to test clearances. I looked into vapour blasting and it still is an option, But i was taking some rust/dirt off of the engine and happened to stumble upon what brass wire did to the case. I really like the pattern i got just from the wire and some fine grit sand paper. Only thing is some parts are untouched due to the size and length of the bit.

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #57 on: November 30, 2015, 07:33:32 PM »
I know i am scratching the aluminum but i like it. Here are some pictures of the damage/awesomeness however you want to view it.

Offline edwardmorris

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #58 on: December 01, 2015, 12:31:23 AM »
If Vapor Blasting is an option, don't bother with the wire wheels. And yes, those nasty dremel brass buggers shed like crazy and get into places you don't want them getting into.

For the rod bolts, go with the later year ones that can be torqued up to a higher value, added peace of mind. The part numbers are somewhere in both mine or Dave's build threads, I'll post it if I find them. Or you could just get a set from Mike Rieck, he usually has some in stock.

Offline calj737

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #59 on: December 01, 2015, 03:28:34 AM »
A Dremel or air grinder with ScotchBrite discs (Green/Red) make very short work of cleaning and "scuffing" your cases, and virtually no erosion with them. Downside to what you're doing is the aluminum will oxidize very quickly once its cleaned.

Gentle glass beading produces another soft lustre finish, but like all blasting, requires diligent cleanup afterwards. Vapor blasting actually leaves a protective finish because its a "peening" process.

Me, I'd stay clear of wire wheels for what you're doing. Its generating some damage to the cases beyond its "cleaning" them.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #60 on: December 01, 2015, 02:00:16 PM »
Ill have a go with some scotch brite for some reason i really dont want to vapour the case, the after pictures are too perfect. The cylinders and head are what i really want to get blasted,  looked up places in LA and only found one, guess im giving them a call!

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #61 on: December 01, 2015, 03:40:26 PM »
Really like what the scotch brite pad does! Gonna go over all the scuffs from the wire wheel and pick up a bit for the dremel or compressor sometime this week. Also sent a message to Mike Rieck to see if he has a set of those connecting rod bolts.

Offline Davez134

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #62 on: December 01, 2015, 05:47:03 PM »
Here is a link to a post in my thread with part number for bolts

http://forums.sohc4.net/index.php/topic,139768.msg1617771.html#msg1617771

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #63 on: December 01, 2015, 05:59:06 PM »
Awesome, thanks for the link Dave! Was going to look through your guys threads while i was at work since there's nothing to do here sometimes at night... I'll look through everything and do some extra research too.

Offline Davez134

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #64 on: December 02, 2015, 08:28:34 AM »
Nice. I've (allegedly) accomplished much research and purchasing while using the computer at work

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #65 on: December 02, 2015, 05:40:09 PM »
Looked into the bolts, bearings, and studs. The list gets longer and longer! But narrowing them down to the specific ones is also a great feeling.

Decided i might as well get to the stator cover that has been sitting in a box, it was in pretty horrible condition as it looked like the previous bike it was on was laid flat on its left side. Got the dremel and some 150 grit with some promising progress! I forgot to take a picture of it before i started, but the ebay photo will have to do... Sneaky seller drenching the cover with oil to hide the extent of the damage, but little does he know what its starting to finish up to!

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #66 on: December 08, 2015, 08:19:51 PM »
Past week, ive just been ordering parts and polishing parts. Finally had the time to take out the rest of the valve guides and got the points stud off... As i got overly anxious taking the stud off i thought vice grips would suffice to twisting it off. I was very wrong... Managed to slice my hand open and finally forced a 4.5mm socket onto the stud to get it off. I know i could have just double nut the sucker but i had already stripped the thread. Lesson learned on studs!

Offline calj737

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #67 on: December 08, 2015, 08:23:31 PM »
You will almost never find a pair Vise grips to be the "right" tool when loosening parts from these bikes. This falls into the "PO Ham-fist Treatment" category.

Not to sound insensitive, better your hand than the crank. Your cut will heal, shearing that stud would be catastrophic.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline edwardmorris

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #68 on: December 08, 2015, 08:27:00 PM »
Past week, ive just been ordering parts and polishing parts. Finally had the time to take out the rest of the valve guides and got the points stud off... As i got overly anxious taking the stud off i thought vice grips would suffice to twisting it off. I was very wrong... Managed to slice my hand open and finally forced a 4.5mm socket onto the stud to get it off. I know i could have just double nut the sucker but i had already stripped the thread. Lesson learned on studs!
Gloves dude! Delays due to injury suck. And I'd look for a replacement timing stud if you had to wrestle so much with it (even if the threads had survived).
« Last Edit: December 08, 2015, 08:41:19 PM by edwardmorris »

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #69 on: December 08, 2015, 08:51:39 PM »
Ya calj, thought the vice grips were alright since they were able to help get the kickstart pin out... but nope i was failed! Not at all insensitive, i was more concerned about the crank as well.

Ed i just took my gloves off, just my luck. Haha unless i am able to use the timing stud with a 4.5mm socket stuck to the end of it, i agree i need a replacement.

 

Offline edwardmorris

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #70 on: December 08, 2015, 08:55:08 PM »
Be REALLY careful when installing the new one and setting up the final timing. My new one bent ever so slightly during setting static timing that it had a jitter on the 2-3 timing. Had to painfully set up the dial gauge and fix the runout before it came back in sync.

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #71 on: December 08, 2015, 09:01:37 PM »
Thanks for the heads up! When i get into the timing ill definitely move a little slower.

Offline Restoration Fan

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #72 on: December 09, 2015, 04:52:16 AM »
Nice project.  Subscribed.
Ron

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Offline Davez134

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #73 on: December 09, 2015, 03:23:05 PM »
That ignition advance shaft is pretty hard to find. Yamiya has them (at least they did last year when I bought a few)

Offline mashfu

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Re: 1974 cb750 fun (STEP 1: Engine)
« Reply #74 on: December 09, 2015, 08:41:25 PM »
Picked up one when i ordered all the case and rod bearings from yamiya! Next are ball bearings and other little trinkets!