Honda CB750 Cafe Racer FIRST START after Engine Rebuild | Honda Cafe Racer Project Bike | 25

Honda CB750 Cafe Racer FIRST START after Engine Rebuild | Honda Cafe Racer Project Bike | 25
In this video I finally try to start my CB750 SOHC Cafe Racer project bike following major work on the engine.
Things that I used.
Motorcycle Auxiliary Fuel Tank: ebay.us/7aeVud
Battery Jumper Cables: ebay.us/opZgON
It has seemed like a long time since I started work on this bike, and to be honest I did expect to be riding it this year 🙁
When I first started the bike, I expected the engine to be working quite well. It had definitely had quite a bit of work before I got it. The PO did however say, he had never had it running, and felt that it would need to be worked on further. He didn’t tell me that it was a big bore engine, maybe he didn’t know.
When I started the engine for the first time it actually ran relatively well. But it had quite an oil leak that seemed to be coming from the cylinder head. This led to me removing the engine and stripping the top end. I was in for quite a surprise, as I found what I originally thought were 812cc Yoshimura pistons.
It actually worked out that although marked 812 these were 823cc pistons, apparently Yoshi used the same blanks, but machined them bigger. I think this had led to the previous builder making a big mistake. The piston rings that were fitted were for the 812cc, which meant they had ring gaps that were far too big, and were actually scoring the bores.
In the end I had to source a completely new (used) top end for the engine. I also had to get the barrels bored to work with the pistons. This meant quite a delay and a lot more expense than I originally thought would be needed.
In this video I have the engine back in the frame, and I just need to fit the oil tank and lines as well as the carburettors before attempting to start the bike. This all goes quite well, but when I actually pull the bike out and try to start it it seems that the starter is not working correctly. At first we thought it was just a weak battery issue, but after trying to address that we came to the conclusion that it was an earthing issue.
There still seemed to be a problem, but when I earthed the battery directly to the engine it turned over quite well and we did get it to start. In fact it does start quite well, but it is obviously not running on all cylinders, all of the time.
I will have to spend some time investigating the starter/earthing issue and the uneven running before I go any further. This will be in the next episode, it looks like refinishing and putting the tank on, and sorting out the seat is still a long way off 🙁
I would still like to think exciting times ahead 🙂
For more helpful how-to guides and restoration project logs, visit our blog: www.spannerrash.com/
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[@christopherastbury-mg2iz]

I'm trying to work out what's more relevant, the bike starting, or that father and son bonding that we are experiencing. well done lads...loved it

[@SPANNERRASH]

It's great working as a team, especially when things are going well ;)

[@petermosdell580]

Still remember the whole family putting that engine in the frame. Great to see it burst into life 👍

[@SPANNERRASH]

You and me both!

[@grahamparker9470]

Fit a new starter SOLENOID if you haven't already...makes a massive difference my cbx was sluggish for years then i fitted a new SOLENOID and it starts first press and engine turns much faster...😂 great build chaps.

[@SPANNERRASH]

I'm pretty sure it was a mixture of the Lithium battery and a poor earth. It has a new solenoid, but I had a lot of problems with a kill switch once, really odd symptoms. Thanks for the encouragement.

[@andreokazaki14]

Congratulations! I have been following this build from the start. When it was running and the camera was focused on the bike, Your big grin was just visible. I know the feeling of the first start up of a long project. I'm looking forward to your first test ride.😀

[@SPANNERRASH]

Awesome, thank you! First starts are the best, usually :)

[@1961kickboxer]

That’s a great looking bike ,well done for the restoration

[@SPANNERRASH]

Wait until you see it finished!

[@MrEvilmonkeyman]

God this thing looks great. Can’t wait to see what all happens along the way!

[@SPANNERRASH]

Me neither. I am really looking forward to getting this on the road.

[@tommac9119]

Another great video mate, fantastic, it’s getting there and worth the hassle ( its the way we learn). Given me inspiration to get back into shed and sort my k2 out 😁 👍

[@SPANNERRASH]

Great to hear! Better in the shed than in bed! Ha.

[@CB750K]

That thing purrrs like a tiger! (If they could purr) It's incredible. Far quieter than my stock 4to4 exhaust. Dang. I think you have a real keeper here. It's so satisfying when hard work pays off.

[@SPANNERRASH]

I'm surprised if it is quieter than your stock exhaust, I must have turned the volume down too much :) I was told it sounds like the 4 horsemen of the apocalypse by another bystander, It is great that it runs, and now I can start to turn it into a rider.

[@CB750K]

A month later I discovered that all 4 of my silencers are missing the end cap diffusers. I've had several CB750s, but this is my first with 4-to-4s, so I didn't notice anything missing. Explains why my bike is so loud, and might account for a bit of difficulty tuning my carburetors.

[@mulliedog1]

Excellent!!!!!! The sweet sound of success!!!

[@SPANNERRASH]

Many thanks!! I didn't realise that the sweet sound of success was so loud :) Maybe I need a baffle!

[@Mrtweet81]

That was a lovely executed 26 point turn 😊

[@SPANNERRASH]

I always try to be elegant and graceful! :)

[@ethanhawkins849]

Absolutely love to see it running! Fantastic work

[@SPANNERRASH]

You and me both! It's the best part of any project.

[@jimgahnfelt1020]

Congratulations! 😃

[@SPANNERRASH]

Thank you! Cheers!

[@jasonwight7726]

Beauty! Glad you were able to figure it out! Sounds brilliant mate! Cheers 🎉

[@SPANNERRASH]

Thank you! Cheers! Still a lot of parts of the puzzle to get right, but it will be worth it.

[@dcmotive]

Lookin good!

[@SPANNERRASH]

Cheers

[@10summoners]

Fantastic work gents! Looks and sounds great for a first start! Can't wait until my son returns home in a few years for some great times like you are having!

[@SPANNERRASH]

Fingers crossed! First starts are always an exciting time, even better when shared.

[@philw4053]

Well done! Great to see it burst into life after all that work. Really looking forward to the "first ride" video!

[@SPANNERRASH]

So am I. Need to get it ready for Spring, Winter is setiting in quickly now.

[@robbateman7987]

Congratulations, good work.

[@SPANNERRASH]

Thank you! Cheers! Still a way to go.

[@BatFastard01]

Top darts Sir!

[@SPANNERRASH]

Thank you kindly

[@1234567marks]

Great to see it running, inspired me to get mine out, not ridden it since January, it’s at the back of the garage with other bikes infront of it so tends to get ignored!, anyway good work 👍👍

[@SPANNERRASH]

Thanks, it still needs quite a lot doing, but now the engine is running I am inspired like you to ride it. That won't be for a while yet, Winter to contend with first.

[@onemanhisdub1969]

I've have total respect for you guys. I've been looking for a nice 750cc Are the parts easy to source on these? All the best David.

[@SPANNERRASH]

It's possibly easier and cheaper to buy parts of these than for some modern bikes. Take a look at CMSNL and David Silver.

[@thomasceruzzi1871]

Did the rearsets come with the bike or did you source them? Any clue to the manufacturer? Love the vids, found you a few months back and was anxiously awaiting hearing her run. I have the same megaphone on my DOHC, sounds great but can get buzzy after a bit lol. You've made me drag out my SOHC and getting back into finishing that build. Cheer from the U.S.!

[@SPANNERRASH]

Thanks for the positive words. The rearsets came with the bike, but they are Tarozzi Pedane Rearsets for a 750 F1. The brackets that they are fitted to on my bike have been custom fabricated, but I think they can be fitted to a standard bike. The exhaust does seem a bit too loud, I was wondering if some sort of baffle could be fitted, but that is something for the future. Good luck with getting your SOHC finished.

[@daveco1270]

She sounds good. Why did you go with the green 3 ohm Dyna coils rather than the black 5ohm coils? The stock coils on the CB750 were 5 ohms. Did you have to put a ballast resistor on it to make the 3ohm coils work? You may want to make a bracket to hold that muffler to the frame, it's bouncing up and down a bit... and it's right under your foot peg so hopefully it won't burn the bottom of your boot. : )

[@SPANNERRASH]

The coils came with the bike along with Dyna pickups. I assumed they were the right ones, but now you have mention it I will look into it. I shouldn't take anything for granted. I am going to make a bracket for the exhaust, but I am also comtemplating changing it, It is very loud.

[@kevinsmith1044]

Does that ever sound great or what

[@SPANNERRASH]

First starts always sound great. When they start :)