Author Topic: 750 DOHC Project  (Read 26686 times)

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Offline ljonny18

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Re: 750 DOHC Project
« Reply #25 on: April 02, 2012, 02:39:13 AM »
I eventually got impatient and took a hammer and long screw-driver to the clutch bolt :S and decided it would be easier and faster to simply replace the bolt with a new one on the re-build (it looks although someone has already take a hammer to it anyway):
















Offline ljonny18

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Re: 750 DOHC Project
« Reply #26 on: April 02, 2012, 02:39:45 AM »
Moving on:
















Offline ljonny18

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Re: 750 DOHC Project
« Reply #27 on: April 02, 2012, 02:40:17 AM »
I could not seem to get the alternator rotor off... After a while of trying I thought I would leave it for now and do a bit a research before I broke something :(












Offline ljonny18

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Re: 750 DOHC Project
« Reply #28 on: April 02, 2012, 02:40:44 AM »
As I am now a bit stuck, a lot of the engine is already apart and space in the garage is slowly getting less I thought it was a good time to have another clear up and organize everything... I have learnt (in my case at least) keeping  your working space tidy and organizing your parte and tools make the whole process a lot easier ....




Offline ljonny18

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Re: 750 DOHC Project
« Reply #29 on: April 02, 2012, 02:41:31 AM »
Did not manage to get much time in the garage this weekend : ( I did however manage to (eventually) get the alternator off:







and prepare the rest of the engine for separation.... :











Upside down and ready for separation (I hope) :)




Offline ljonny18

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Re: 750 DOHC Project
« Reply #30 on: April 02, 2012, 02:41:57 AM »
sump off:








Offline ljonny18

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Re: 750 DOHC Project
« Reply #31 on: April 02, 2012, 02:42:20 AM »
This does not look too good :S





Anyone know how much I should be worried with such shards of metal ???






Offline ljonny18

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Re: 750 DOHC Project
« Reply #32 on: April 02, 2012, 02:42:56 AM »
onwards :)















Removing the final bolts for separation:






Offline ljonny18

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Re: 750 DOHC Project
« Reply #33 on: April 02, 2012, 02:43:23 AM »
Stuck :( the casings do not want to seperate ....



I have tried loosening the seal with both a rubber mallet and also using a larger haller and wooden block, but the seal does not want to break :( I am pretty sure I have removed all bolts (maybe there is one hiding ???).

Would it help to heat the seal / casings up ? would this help the separation ???

As always, any advice is welcome and appreciated.

Offline ljonny18

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Re: 750 DOHC Project
« Reply #34 on: April 02, 2012, 02:44:01 AM »
I finally got the engine casings separated, after heating the seal and using a bit of gentle persuasion with a wooden block and hammer:





Note: if you have any issues seperating the engine, I found heating up the seal very effective... :





Separated :)


Offline ljonny18

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Re: 750 DOHC Project
« Reply #35 on: April 02, 2012, 02:44:26 AM »
I started removing the connecting rods, camshaft and gear box... and all in all, its looking pretty good condition wise (considering it has what I believe to be a v-hard 60k mile life):












Offline ljonny18

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Re: 750 DOHC Project
« Reply #36 on: April 02, 2012, 02:44:51 AM »
All engine parts now ready for inspection:


Offline ljonny18

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Re: 750 DOHC Project
« Reply #37 on: April 02, 2012, 02:45:17 AM »
Let the inspection commence :)

















The camshaft, camshaft bearing and connecting rod bearing all look in good condition... all are v-smooth with no scratches / marks... I am guessing it makes sense to replace all bearings in any-case just to to be sure - or, is this a little OTT ??? is is worth replacing all bearings even if they appear to be good (remembering thay already have 60+k wear on them) ...

I will be checking all other parts for wear and will be replacing all gaskets and seals... Is there anything else that I should check / renew at this stage of a build... ??? As always any help / advice is much appreciated !!! (this is my first build, so I am still a bit of a novice :) )

Offline ljonny18

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Re: 750 DOHC Project
« Reply #38 on: April 02, 2012, 02:46:08 AM »
I have not managed to get much done this weekend as the engine casings have been away to get de-greased / cleaned up a bit ...

My neighbor works at a local car garage and has access to a good parts degreaser so kindly allowed me to take some bits down to get cleaned up

Parts all loaded in the van:   




Offline ljonny18

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Re: 750 DOHC Project
« Reply #39 on: April 02, 2012, 02:46:30 AM »
We left the parts overnight and gave them another going over the next day...

I used this time organizing what parts I need to oder (all new gaskets, bearings and seals etc...) and also spent some time cleaning up the garage so its a bit more in shape for the re-build when the casings come back and parts arrive :)

Believe it or not - this is after a good few hours cleaning up and reorganizing (although it does not look like it) :S



I also had to move the parts out of the apartment :( so I got some new shelves to try and keep it all in shape...





I also used this free time to sort my mountain bike out for the summer as the sun has started to shine here :)


Offline ljonny18

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Re: 750 DOHC Project
« Reply #40 on: April 02, 2012, 02:46:52 AM »
The casings came back and cleaned up pretty good... Just need to wait for the parts to arrive before I can start re-build - hopefully they will arrive this week !!!












Offline LesterPiglet

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Re: 750 DOHC Project
« Reply #41 on: April 02, 2012, 03:17:22 AM »
So where did the pieces of metal in the strainer come from?
'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Draw and drawer. Could care less/couldn't care less. Bought/brought FFS.


Les Ross.            Certified by a Professional

Offline ljonny18

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Re: 750 DOHC Project
« Reply #42 on: April 02, 2012, 03:26:49 AM »
So where did the pieces of metal in the strainer come from?

They turned out to be mainly rubber / gummi which I think came from / fell down from the cam chain tensioner as the tensioner was a bit broken / corroded :)

The large piece of metal turned out not to be metal :) It did look and feel like metal at a first glance, however a further look proved it to look more like plastic... I heated it up a bit and it was also flexible like rubber :)

Offline grcamna2

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Re: 750 DOHC Project
« Reply #43 on: April 02, 2012, 06:07:22 AM »
Nice BIG Project on you're 83' CB750 DOHC..you're doing meticulous and careful labor & documenting the progress of you're Build for us to learn about. Welcome to the forum  :).Did the previous owner give you any indication that this one was such a "sludger" as far as engine oil ? That requires Plenty of Labor, but it looks like you're winning the battle !
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline ljonny18

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Re: 750 DOHC Project
« Reply #44 on: April 02, 2012, 07:11:18 AM »
Nice BIG Project on you're 83' CB750 DOHC..you're doing meticulous and careful labor & documenting the progress of you're Build for us to learn about. Welcome to the forum  :).Did the previous owner give you any indication that this one was such a "sludger" as far as engine oil ? That requires Plenty of Labor, but it looks like you're winning the battle !

@grcamna2 - No the previous owner gave me no indication re its history / abuse etc... They guy I bought it off, had also bought the bike as a project but did not do anything with it... It has just been standing in his garage for over a year. I think (get the impression) that the guy who had it before him simply did not look after it and abused it :) Having said that... although it is very tatty and has "sludger" oil ;) the engine internals look in pretty good condition (in my novice opinion). I hope im winning the battle... but lets see - watch this place ;)

Offline Magpie

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Re: 750 DOHC Project
« Reply #45 on: April 02, 2012, 08:26:23 AM »
Great job and documentation! I'm learning a lot as I'm new to the DOHC Hondas http://forums.sohc4.net/index.php?topic=104584.0 Thanks for posting your work. Cliff.

Offline ljonny18

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Re: 750 DOHC Project
« Reply #46 on: April 02, 2012, 08:41:45 AM »
Great job and documentation! I'm learning a lot as I'm new to the DOHC Hondas http://forums.sohc4.net/index.php?topic=104584.0 Thanks for posting your work. Cliff.

No worries, your welcome - I am also learning a lot as I am also new to the DOHC Hondas ;)

Offline somesuch

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Re: 750 DOHC Project
« Reply #47 on: April 02, 2012, 10:20:12 AM »
Just an observation, but the bottom case main bearings show wear, they are worn through to the copper layer. The clutch basket is sometimes lose and would make a noise in neutral with the clutch out, that noise going away with the clutch pulled in. Primary chain often makes noise as well. The window on the shifter should be enlarged as per Honda TSB for a lower chance of missed shifts/possible popping out of gear. The exhaust valves should be checked especially on the inside cylinders. Might make sense to build a bigger motor now on your cases with a 900 crank/and a bigger block (1000 and 1100 blocks had better cooling fins)

those are desirable factory "sport kit" (in US, standard in Europe) rear sets, there should be a corresponding throttle control with the cables coming out on top.....another desirable piece if you have it. 

CB1100f.net is a great resource for you build.

I may have an old beefy ATK aluminum swing arm for that bike. If you want me, I will look for it.

Offline grcamna2

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Re: 750 DOHC Project
« Reply #48 on: April 02, 2012, 01:40:43 PM »
ljonny18,
     That is a Very Nice mountain bicycle  8) ; who is the manufacturer ?
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline FrankenFrankenstuff

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Re: 750 DOHC Project
« Reply #49 on: April 02, 2012, 08:25:10 PM »
WOW! Such a fast developing thread! Great job Jon.