Honda CB750 Restoration (Not sure of the year, I think '79 or '80)

[RideThis]

Successful night on the CB750... The mother effer runs!!! Feels pretty good to make that happen after 15 years of rotting... It runs pretty crappy but it runs... I need to figure out how to post a video, but I will once I do...

About it running... It fired right up after the carbs filled with fuel ... And as it heated up it started to have issues ... Lots of smoke... White smoke... Possibly a fair bit of carb cleaner still being blown out... I'm not too concerned, I'm not working Thursday so I'll get a whole day to mess around with things... And of course, oil leaking from the valve cover gasket... I imagined oil leaking well before I got this 'ting running...

My replacement cam holder/bearing cap bolts, (Next to one of the original bolts)...

The camshaft holders all torqued down... Without problems this time...

Valve cover back on...

Engine back into the frame...

Carbs installed...

Draining out ancient sludge...

Fuel tank, electrical hooked up... (+ cleaned up engine cover)

Vid of first start up coming soon...

Cool story about that vid... First thing this morning, in my excitement, I go to show a co-worker... But I'm soooooo tired that I go through the motions of deleting it without realizing it... Good thing I've got another clip, it's just got me talking in it... The silent one was better...

So, one step closer... But there's still a ton of things to do!

Edit: I'm an exhausted dummy... Vid's on my computer already... Diresgard everything I said...

 

[TheDirty]

+1 on the great thread to read.

 

[Cat13]

Looks awesome. Gonna be nice to see the finished pics.

My 360 leaks and gonna leave it. But currently rewiring her.
Are you leaving the wiring stock or going to clean it up?

 

[RideThis]

Looks awesome. Gonna be nice to see the finished pics.

My 360 leaks and gonna leave it. But currently rewiring her.
Are you leaving the wiring stock or going to clean it up?

Def going to sort out my oil leak... As for the wiring... Hmm... I have no idea what challenges lie ahead in regards to wiring... I'll have to cross that bridge when I get there...

 

[Red_Liner740]

I dont know about the old Honda head bolts, but when i was doing engine rebulds on Volvo's the head bolts were the torque to yield or something like that...as in, once they are torqued down once, you arent supposed to reuse them. I guess you found out why...lol

good job on the rebuild BTW.

 

[shewie]

Loving this thread!

BTW, the Honda dealer up here (Peterborough) sells those 30a main fuses so you don't need to Frankenstein it.

 

[RideThis]

I dont know about the old Honda head bolts, but when i was doing engine rebulds on Volvo's the head bolts were the torque to yield or something like that...as in, once they are torqued down once, you arent supposed to reuse them. I guess you found out why...lol

good job on the rebuild BTW.

Lol, I'm still using the ones that didn't break, just everything it torqued to the lowest spec now...

Loving this thread!

BTW, the Honda dealer up here (Peterborough) sells those 30a main fuses so you don't need to Frankenstein it.

I'll keep that in mind for later, but if I can clean up the frankenstein I might just keep it... The 30A minis are much more available...



Update:

1 -First start video is up!

[ame="http://www.youtube.com/watch?v=TnLLd8y-CYs"]YouTube- Honda CB750 Custom Project, First Start[/ame]

2- Second video is up, this was her running right before she stopped and gave me problems...

[ame="http://www.youtube.com/watch?v=ZerlSndKpo4&feature=channel"]YouTube- CB 750 Custom Project, Running with the pipes on...[/ame]

3- So, bike's running, and starts to idle erratically... Then dies... Back to the basics: Fuel, Ignition, Compression... Remove the carbs again and here's what I find... And I was a bit bent over it but lessons learned...

So after learning that my clean fuel tank was filthy as s***, I decided to strain all the fuel over and over... This is how bad it was the first strain...

2nd time...

3rd time...

There was def a 4th time, and maybe a 5th... But I continued until it was almost clean... Then cleaned the carbs again... And got the bike to run on 2 cylinder (#3 + #4) and it was misfiring in #2, not firing at all in #1... So I cleaned the carbs again and even better... No video of it running after that cleaning but it ended up running decent on all four cylinders... Let it run a bit and added a carb cleaned to the fuel...

While it was running, more chrome cleaning...

Started to look into the ignition, been sitting in ATF since I posted the pic when I first got it out of the bike... This guy's going to give me a hard time....

That's it for today... Remember flush your fuel tank many, many, many times if it's rusted out!!!

I don't even know what's next yet...

 

[Hachi-Roku]

PM Sent

Oh and as for your Tank
no matter how many times you flush it
It's going to flash Rust
You'll need to coat it with Kreem (or something similer)
I've found Those coatings that come in the Muriatic Acid kits are pretty thin and don't last very long

 

[Cat13]

Def going to sort out my oil leak... As for the wiring... Hmm... I have no idea what challenges lie ahead in regards to wiring... I'll have to cross that bridge when I get there...

Theres tons of wiring diagrams. Just heads up green is ground on Hondas. But we are rewiring mine cus the stock wiring is a mess and we wanted to make it easier to trace problems. But there are tons around some cool hippy looking ones which so far we are finding the best.

Loving this thread!

BTW, the Honda dealer up here (Peterborough) sells those 30a main fuses so you don't need to Frankenstein it.

Theses a Toronto surplus store which we found a bunch. But we upgraded the fuses so that should we have issues out riding I can pick up a fuse no problem at any gas station or hardware store. Up to you what you do. Otherwise I suggest just carry a bunch of the stock fuses.

PM Sent

Oh and as for your Tank
no matter how many times you flush it
It's going to flash Rust
You'll need to coat it with Kreem (or something similer)
I've found Those coatings that come in the Muriatic Acid kits are pretty thin and don't last very long

Por15.com Is what I used. So far its a nice coating and you get it in two days. Quick shipping. Theres a kit for small tanks. Suggestion though we found it pluged my air hole so watch for that. Easy to fix so just something to be aware of. Also to be safe I ran a fuel filter just incase there was some old crap that didnt get removed.
But there are options to what product you use. Each is personal choice. I just went with what more people recommended to me.

 

[ROOKIE]

hey bro.
this project is inspiring.
My dad's friend just dropped off a bike at my place and it looks very simillar to what you started with.
How is your project coming along?
did you finish it?

 

[RideThis]

hey bro.
this project is inspiring.
My dad's friend just dropped off a bike at my place and it looks very simillar to what you started with.
How is your project coming along?
did you finish it?

She's far from done, winter has shut me down! No heated shop to work from. The project and pics will return with the warmer weather... Got it running before winter hit, so its going to come right apart again in the spring and I'll get it painted where it needs paint...

You'll see when the pics start coming!

 

[PaoloC]

Hey Ridethis... cool bike I have a 78 CB550 and have no doubt you will love that 750... I go on www.forums.sohc4.net although its mostly info for SOHC bikes there is much relevant info regarding Carbs, ignition, wiring etc... look into the project section there are tons of guys going through exactly the same thing as you.

When you had the engine out and apart it was your chance to replace all gaskets and also check on your timing chain tensioner as they tend to seize, also the carbs are going to have to come apart completely and get new gaskets for the bowl, also make sure you get new clutch/throttle cables. My suggestion for the rusted part is to soda blast them (google it) or sand blast.... hand polishing wont do anything for the pitting anyhow. These bike are super fun to drive (with lower handle bars) so dont give up on it...

 

[klf33]

this has to be one of the best Threads I ever seen online... Keep it up man.

 

[el_felo]

wow this is an awesome read.. can't wait for some pics.. great work so far!!

 

[Baggsy]

I'll check with my friend when I get a chance. He has a CB750K that he has rebuilt a couple of times.
He just got an original 4 into 4 last year, not sure what he did with the old pipes.
He might know about some of the issues that you are having.
He has an id on this site, but I don't think he ever uses it.

 

[RideThis]

Its almost time to get back at it...

 

[82CB900cNick]

Nice project... if you have any questions I will do my best to help. I have an 81 CB900c my dad bought new back in the day and handed down to me (daily bike) and a 83 CB1000c I bought last year for a project. See my new thread here: http://www.gtamotorcycle.com/vbforu...Revival-and-Restoration&p=1542086#post1542086

I want to find a 750c for my next project and your thread is nice to see someone else with same enthusiasm to restore one of these Honda DOHC fours.

Great work!

Let me know if you need any parts for it, I can try and direct you to some.

 

[RideThis]

Alright, I'm going back in for more!!! Pics to follow...

I wonder how the ignition's doing...?

 

[Venom01]

PM Sent

Oh and as for your Tank
no matter how many times you flush it
It's going to flash Rust
You'll need to coat it with Kreem (or something similer)
I've found Those coatings that come in the Muriatic Acid kits are pretty thin and don't last very long

+1000000000000
Many time this made me want to smash my head in. You always think you got it, then more shows up. It never stops, get your tank coated.

Sent from my Nexus One using Tapatalk

 

[RideThis]

So, tonight I ripped it all apart again. Engine out, front end off... Down to the frame and wiring. Not at home tonight so can't put up pics but it's nothing too exciting... I need to figure out how I'm going to repaint the frame, my options are: paint gun, spray paint, or send for powder coating... I figure powder coat will look the best but obviously will cost the most. Any great success stories with spray paint???

Oh and the ignition... No change... lol