CB750K7 Cafe Racer Build

[Doctor Jones]

Whilst I'm waiting for that one-off Manx tank here's a little thing to look out for and it's certainly something that we nearly missed.

When rebuilding the head we noticed that the right hand oil way was open but the left appeared to be closed. Investigating the left we found that it has what Honda call an 'oil control orifice'. It looks like a small socket cap screw. This is basically a reducer that has 4 tiny holes in the shaft feeding a single outlet jet that exits into the camshaft post and is sealed with a rubber 'o' ring. Where the right hand side went, we have no idea but perhaps it was lost in the shot blast process? Anyway, the LH was blocked solid and stopped any fluid transfer whilst the RH was too open providing too much and perhaps causing starvation elsewhere in the bottom end.

Happy ending: One of you lovely American dudes has come to the rescue and is sending us that part. It's not produced anymore and appears to be rarer that rocking horse s**t! So, if your doing this on a CB SOHC make sure all is well, take them out (they simply pull with pliers) and keep those little babies in a safe place.

Hope this helps someone in the future.

 

[drpoyser]

Hey Doctor Jones - did you end up chopping your rear?

 

[Doctor Jones]

Sure did fella. Not sure it's in the right place as I still haven't got the tank AND IF TANKY IS LISTENING, IT'S REALLY STARTING TO GRIND MY GEARS! There, that's better.

 

[johnu]

I would leave it as is! I love those cr tanks, I would mate it with a different seat though (something not as rounded). Bike looks awesome

 

[Doctor Jones]

Thanks johnu. I'm definitely using that tank on the next bike when I'll be able to plan it into the build. Yeah - I'm looking at different seat/tank combinations all the time so we'll see what happens there.

GOOD NEWS.: The Manx tank is under construction as we speak. I just got a photo from the suppliers and we look to be at least half way there. That makes it beer o'clock in my book.

 

[VicSkimmr]

Do you mind me asking how much the CR styled tank was? What was the turnaround time on it?

That seat pan looks a little long to me for a CR750.

 

[Doctor Jones]

Hi Withers. I'll PM you the price details tomorrow and no old chap, I don't mind you asking. Turnaround is probably, realistically, around 20 weeks. I'm quoted less but there are so few people able to fabricate to this quality that they are all super-busy. I ordered 2 CR tanks from another supplier recently who are quoting 35 weeks. That's the same gestation period as us humans but, in the long run, the tanks are way cheaper .
That seat is significantly longer that the CR pan but it's getting hooked up with a wide-line Manx tank (when it gets here). I only placed the seat and tank on that frame to see what it would look like.
Sneak preview of Manx tank in fabrication below. Hope it's here next week so we can get this bike wrapped up and ridden.
Oh, and the weather is suddenly lovely here. Whatever happened to seasons? 8)

 

[VicSkimmr]

Good lord.

 

[Rich Ard]

Christ Jesus. It's beautiful.

 

[johnu]

Do you mind me asking how much the CR styled tank was? What was the turnaround time on it?

That seat pan looks a little long to me for a CR750.

Not sure if you are in the US or not but Sean at Roc city makes cr alloy tanks, maybe he could do it quicker? His work is A1 quality for sure.

 

[Doctor Jones]

Alas, not. I'm in the UK. I do buy parts from the US but I have to be careful as, when you add on our import duty + VAT at 20% + the additional shipping charge for the journey this end, it adds up. I just paid around $150 extra on a purchase of $500 and that stings!

 

[johnu]

Yeah I realise you are in the UK, I was wondering about Withers who was enquiring about the details of your tank. I was born and raised in the UK, now living in Socal though. My dad restores bikes in the UK. I once brought back a Greeves petrol tank on the plane from the UK to the USA, doubt if I'd get away with that anymore! That VAT @ 20% is insane!

 

[VicSkimmr]

Not sure if you are in the US or not but Sean at Roc city makes cr alloy tanks, maybe he could do it quicker? His work is A1 quality for sure.

Yep, I didn't realize he was in the UK.

Yeah I've been through Sean's site. His tanks seem to be more "inspired" by the CR tank than an actual replica but I may go that way anyway. There's also a company in Canada that looks like it does great work but the quote I ended up with was pretty high up there. 10 week turnaround though. I'm just browsing around.

 

[Doctor Jones]

Doctor in the house.....

Been a long time chaps but we are back. Tanky came through and just look at the results.

It's time to get this bike rolling!

 

[teazer]

That tank is amazing. The sides appear to be incredibly smooth and evenly curved. That takes some skill. Worth the wait.

You already know that metal to metal contact is to be avoided at all costs. Make sure nothing touches.

That is so clean.

 

[Hoosier Daddy]

OMG is right!!!
8)

 

[Doctor Jones]

Hi teazer - the tank is rubber mounted and I'm building a sub-frame for the seat to separate it completely from the main frame. I'd like to get that job done this weekend but now the sun is out the current Mrs. Jones has come up with a big bag of ideas to keep me out of the 'shop.

As to the quality of the aluminium fabrication, you have to see it (touch it, lick it) to believe it. The tank is made from 3 sections; 1 small piece at the tail and head yet the main tank is a single sheet. It's fully baffled on the inside too. To watch the guy work is like watching a surgeon. Every anxious moment waiting for it to arrive, forgotten! And really, it was only 17 weeks from order to getting it. I'll factor it in next time.

Hey HD - how d'ya like them apples, eh? I climbed on and my knees just slipped into the tank recesses as my feet fell perfectly on to the rear sets and my hands settled on the controls. I grabbed a handful of throttle - the flag dropped .......then I woke up. No engine. How frustrating!!!

Just one more picture. Sorry but I just love that tank.

 

[Union Jack]

Beautiful!!
Where did you ordered the tank from?

 

[Doctor Jones]

If anyone is interested in the tanks you've seen here then please PM me for further details. I can supply them but you need to be aware of issues concerning fabrication, fit, delivery times and cost. I could just give all the details here but I've done my research and it may just save you a lot of heart-ache.

I'm not out to make a profit, all I want to do is safeguard my investment. I have several tanks on order at present, I know the guys are flat-out busy so I want to filter the inquiries. Sorry to be an ass here but if you PM me I will give it my best attention.

Thanks for your understanding.

 

[Doctor Jones]

Thanks miffa and thanks also for the info you provided earlier. I'm certainly going to act on it in the near future. I got my knickers in a twist over this one but, when all said and done, the results speak for themselves.

8) 8) 8) 8) 8) indeed!