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Author Topic: 1982 CB750F... The resto-not  (Read 33084 times)

Offline pidjones

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Re: 1982 CB750F... The resto-not
« Reply #270 on: Feb 11, 2019, 16:30:42 »
BTW, that's isoprophy alcohol. The 91% is best, as the 70% "rubbing alcohol" is 30% water so it doesn;t evaporate so fast and lets the alcohol have time to kill germs. You can get 91% at most drug stores and Walmart these days.
"Love 'em all.... Let God sort 'em out!"

Offline Nybz

  • Posts: 31
Re: 1982 CB750F... The resto-not
« Reply #271 on: Feb 11, 2019, 17:27:26 »
I think you are on the right track to clean up inside the engine while you got it open.
Compression is good yes, but the peace of mind checking everything out before you put the engine back in the frame is priceless. Plus new skills is great!

Lapping some leaking valves is pretty easy with the right compression tool. Just don’t lap too hard as there is a hardened thin layer on the valve face and lapping will get rid of it and the valves life will be shorten dramatically.

Honing (can rent the tool if need) and reringing is pretty straight forward. Maybe not needed and these rings are pretty solid stock.

valve stems....these ones are way better then stock. if you are not on the Cb1100f web forum, check it out.
http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=75877
He also has upgrade cam holder bolts, which are higher grade so they don’t break as easy. FYI only 9ft/lb torque on those puppies. Manual says 12 ft/lb or something, you will snap bolts with that.

Cam chains and cam tensioners for sale....not cheap, but better then stock and will last longer then you/your bike.
http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=86245

You can get a full seal kit at a pretty good price. It would require splitting the cases, but who wants a oil leak on a fresh engine? Plus gives you a chance to check your rod and main bearings.

There are four o rings that go on the back (carb side) on the middle studs (at least on my 1979 model) that need to be replaced. Also larger o rings that go around the cylinder in between the base and cylinder.
You can still get the dowel pins, they are sometime just easier to just replace then to try and get them out and damage.

You will want a full engine gasket set and not reuse the base gasket. I use a spray on copper coat for base and head gasket that has worked great on cheap gaskets.

If your insulators are not just frozen and are rock hard from age/heat, they will have a hard time sealing against air leaks. I havent checked them out but there a super cheap aftermarket set on eBay. I opted to get genuine, as they are still available.
The carb-airbox insulators are always cracked and leaking, do your self a favour and get a new set of yours are old. If they aren’t cracked now they will be once you start playing with them more.

If you want some better performance, think about replacing your 750 cams with 900 cams. Direct swap.

Looks good! Will be checking on your progress.
1979 CB750 LTD collectors plates
1979 CB750 K current custom rebuild
1980 CB750 F in waiting...

Past bikes
1982 GL1100
1980 CB400

Offline pidjones

  • Posts: 1049
Re: 1982 CB750F... The resto-not
« Reply #272 on: Feb 11, 2019, 20:19:19 »
And to pull the dowel pins without  damage (except possibly to the dowel pins); find a drill bit that you can just fit the shank into them, put it inside the dowel while you grip them with pliers. This keeps from collapsing the pin and gouging the inside of the case/jugs/head.
"Love 'em all.... Let God sort 'em out!"

Offline CrabsAndCylinders

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Re: 1982 CB750F... The resto-not
« Reply #273 on: Feb 12, 2019, 01:07:52 »
 

Fuck it’s cold here. “How cold is it?”  So cold I saw a cop tazering himself to keep warm.


That"s shocking!
Lighter, Quicker, Faster.
ZX-14, 900F x 2, 1100F, R100, CBR600, SR500, GT500, RZ350, KZ1000 x 2, Moto Guzzi Lemans lll, CBX550, RD 350, 750 SOHC police special, RG250, TL1000R, GT750, KTM Super Duke 1290 R, Harris/Z-1, Norton 750 Commando, Green 77 KZ650

Offline advCo

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Re: 1982 CB750F... The resto-not
« Reply #274 on: Feb 12, 2019, 09:47:11 »
And to pull the dowel pins without  damage (except possibly to the dowel pins); find a drill bit that you can just fit the shank into them, put it inside the dowel while you grip them with pliers. This keeps from collapsing the pin and gouging the inside of the case/jugs/head.

I like this tip. I've always just left those pesky dowel pins in place because I've only ever buggered them up trying to get them out. Good to know.

Offline Jimbonaut

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Re: 1982 CB750F... The resto-not
« Reply #275 on: Feb 12, 2019, 10:17:34 »
Thanks as always gents for the excellent help and advice.  Isopropyl alcohol - check (think I still have some from when I worked on the KLR).  Lots of great info there Nybz, and many thanks for the CB1100F forum suggestion - I'm signed up now.  Starting to weigh up pulling the cylinder block now, and glad that I cut my teeth with this kind of work on the KLR and its thumper engine.  And pidjones I'm going to try that dowel suggestion, thanks a lot - it's jammed in the cylinder block tighter than a jar of peanut butter at a squirrel convention.  If it does mangle, are they hard to replace?

Edit - apparently not, found the dowels for a few bucks on bikebandit.com -

https://www.bikebandit.com/oem-parts/1982-honda-750-super-sport-cb750f/o/m151786#sch18760

Good to know
« Last Edit: Feb 12, 2019, 10:29:27 by The Jimbonaut »
"I'm telling you Donnie, nuthin' but nuthin' but right"

Offline Maritime

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Re: 1982 CB750F... The resto-not
« Reply #276 on: Feb 12, 2019, 10:52:52 »
Just add those should you need them to the pile O parts I'm building up for you LOL ;D
The GL Rebirth: http://www.dotheton.com/forum/index.php?topic=68337.0
CX500 Low budget Bobber : http://www.dotheton.com/forum/index.php?topic=43617.0
"Beer makes you feel the way you ought to feel without beer" -Henry Lawson
"Beer is proof that God loves us and wants us to be happy." - Thomas Jefferson

Offline Jimbonaut

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Re: 1982 CB750F... The resto-not
« Reply #277 on: Feb 12, 2019, 10:55:20 »
Just add those should you need them to the pile O parts I'm building up for you LOL ;D
Ha! "We're gonna need a bigger boat greyhound"

They're on the list - $26 US shipped to Canada, $6 shipped within the US.  Shiretown, make some room  8)
« Last Edit: Feb 12, 2019, 10:56:52 by The Jimbonaut »
"I'm telling you Donnie, nuthin' but nuthin' but right"

Offline Maritime

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Re: 1982 CB750F... The resto-not
« Reply #278 on: Feb 12, 2019, 11:01:47 »
Ha, the box your bars came in is like 3 feet long so we can fill that right up LOL.
The GL Rebirth: http://www.dotheton.com/forum/index.php?topic=68337.0
CX500 Low budget Bobber : http://www.dotheton.com/forum/index.php?topic=43617.0
"Beer makes you feel the way you ought to feel without beer" -Henry Lawson
"Beer is proof that God loves us and wants us to be happy." - Thomas Jefferson

Offline Jimbonaut

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Re: 1982 CB750F... The resto-not
« Reply #279 on: Feb 12, 2019, 11:09:54 »
Only 3ft?  Damn, I thought these bars were wider  ;)

Don't suppose those powdercoat samples had arrived had they?  I need to add a petcock and top end gasket kit to the shopping list too - anytime I can return the favour and send a poutine your way mate say the word
"I'm telling you Donnie, nuthin' but nuthin' but right"