Topic: Maduncle's brat style CB750F - now called "The carb eater"

[maduncle]

you may have the running light and brake light wires switched, it will cause the brake light to be always on.  If you have the brake switch set too tight, it will do the same.

Thanks, I will check out the running light wiring and see if that is the cause.

The brake switch is hanging loose and not fitted, so it won't be too tight.

[maduncle]

Things are slowly coming together.

I have all the parts I need now except for the rear set adaptor plates, which are yet to be completed by the laser cutter.

So I have been searching for Honda tools, with little luck her in Australia, is there someone in USA who could buy a couple of special Honda tools from motionpro and post them to me?

I need the following tools:

08-0015 Oil Filter & Clutch Hub Spanner.

08-0385 Counter Balancer & Clutch Hub Spanner for Honda 20mm.

Total cost is around 20 dollars without postage, but motionpro won't post them to me. I can pay up front for the parts and postage to anyone who can buy them for me and send them out to me.

The website for the parts is:

http://motionpro.com/motorcycle/

If anyone can help out - please let me know.

[WhyNot2]

Things are slowly coming together.

I have all the parts I need now except for the rear set adaptor plates, which are yet to be completed by the laser cutter.

So I have been searching for Honda tools, with little luck her in Australia, is there someone in USA who could buy a couple of special Honda tools from motionpro and post them to me?

I need the following tools:

08-0015 Oil Filter & Clutch Hub Spanner.

08-0385 Counter Balancer & Clutch Hub Spanner for Honda 20mm.

Total cost is around 20 dollars without postage, but motionpro won't post them to me. I can pay up front for the parts and postage to anyone who can buy them for me and send them out to me.

The website for the parts is:

http://motionpro.com/motorcycle/

If anyone can help out - please let me know.

Try these people:

https://www.denniskirk.com/282639.sku?utm_source=google&utm_medium=cse

[maduncle]

Thanks for the link budlite282 - they do ship to Australia...

... but at $41 to ship an $8 socket I reckon I still might find a friend in the US of A who could buy them and ship them cheaper than that.

Otherwise I will try to make one from a spare socket that is the right OD.

[seanbarney41]

hey thanks for the nice write up and photos of your rearsets...you have given me ideas I can use on my k5...

[Terry in Australia]

hey thanks for the nice write up and photos of your rearsets...you have given me ideas I can use on my k5...

Here you go mate, lucky for K owners, you can buy these very nice Tarozzi rearsets for only 295 bucks per set from "Fast from the Past". (sorry Cliff, they don't do F2's either.....) You can buy them with rubber pegs or knurled aluminum, but I like the more "industrial" knurled look. I just ordered a set for my K1, and I'll post a pic once I've installed them. Cheers, Terry. D; http://www.fastfromthepast.com/servlet/the-390/Rearsets-Folding-Knurled-Footpegs/Detail


 

[maduncle]

Yep - next 750 I touch will be a K (thanks Terry).

Meanwhile - got my own custom designed rearset brackets back from the laser cutter on Saturday. They could do them in one piece with two bends, so they did them in three pieces in each bracket and tig welded them together. And they did a super neat vey crisp no finishing on my part required job too.

After a quick lick of satin black and I had them on the bike.





Nice fit, look like part of the bike, but...

... there is no way that collector on the 4 into 2 into 1 pipes is going to allow any movement in the brake pedal, so luckily a great guy called Craig from a custom bike shop called The Mischief Makers is back in town and looking for a bit of work. So Craig will get the pipes to modify so I get good clearance and so my Lossa muffler can go back on.

Meanwhile, I fitted off the 'busa rearsets, connected up the linkages, connected up and bled the brakes, and got it all working.





You can just see part of one of Tintop's filter sets in the corner of one of those photos. I did start the bike up with the pipes and Supertrap muffler fitted and it was running way better already.

Ah well, a little more waiting to get the pipes modified and back on, then I can test out the rearsets for real.

[Retro Rocket]

Looking nice Cliff...  I like that the rear sets aren't back too far. What are they like with you sitting on the bike.?  How tall are you.?

[maduncle]

Looking nice Cliff...  I like that the rear sets aren't back too far. What are they like with you sitting on the bike.?  How tall are you.?

Thanks mate - I am a bees thingy under 6'2", and I find the position of the rearsets to be just about right.

I worked on the theory that if my toe ends up where my heel was and my foot is slightly higher up it would be okay. When I began this part of the project, I did position myself on the bike and put my feet where they felt right, then put some tape on the frame to mark the spot.

Only a good ride will tell, but they will surely be better than the 'knees up under my armpits' position that the clip on handlebars and stock footrests were giving me!

[Syscrush]

They really do look like they were made for the bike.  Very nice.

[maduncle]

Thanks Syscrush.

Tonight my mate Craig from Mischief Makers came by and we worked out how to modify the tail end collector where the two pipes join.

We just cut it across the two pipes and flip it over, easy job! Just need to tack a rod across the top end to keep the 4 pipes in the right spot.

So Craig has the pipes and my Lossa muffler now to get the work done.

And I have found a local ceramic coater to do the pipes (in Coburg Terry) so I will get them all painted up nice and proper.

[Terry in Australia]

Thanks Cliff, I'm looking forward to seeing the finished result, I've got a very rare "Porky Allen" 4 into 2 race pipe here with crappy chrome, so a ceramic coating would be superb! Cheers, Terry.

[maduncle]

The CB750 still taunts me.

I got my modified pipe back from champion welder and all round good guy Craig on Saturday and I fitted them to the bike on Sunday morning nice and early, so I could get to a show with the bike by 9.30...

...

... 9.45 and the bike still won't start. I keep trying until the battery dies...

...

... 10.30 and the battery is topped up to just glowing in the 100% on the charger, back in the bike for another try...

...

... battery is flat again - I am going nowhere on Sunday and the battery is back on charge for a good 12 hours this time whilst I work on the CB450 parts for the rest of the day.

So I will try to start the bike again tonight, I might take the plugs out first and clean them this time to see if that helps (?).

I know the bike will run as it did run two weeks ago on Tintops filter setup and the 4 into 2 into 1 pipes before I sent them off to be modified - GAH!

[Terry in Australia]

I've got a 50 buck Supercheap battery booster thingy Cliff, and if one of my bikes has been sitting for awhile I hook it up to start it, and it's amazing how the extra cranking power gets them firing up quick. Well worth the investment! Cheers, Terry.

[maduncle]

I've got a 50 buck Supercheap battery booster thingy Cliff, and if one of my bikes has been sitting for awhile I hook it up to start it, and it's amazing how the extra cranking power gets them firing up quick. Well worth the investment! Cheers, Terry.

Yep - might have to go that way soon, don't suppose hooking my charger up whilst trying to crank it over would do the same job?

Probably not - and a booster would be a useful bit of kit to have, given the bike I am collecting.

[Terry in Australia]

It depends on the charger Cliff, some of the new high amperage chargers are designed for jump starting, but might be too much for a smallish bike battery. Better get the booster mate, they're a very handy device. Cheers, Terry.

[maduncle]

It depends on the charger Cliff, some of the new high amperage chargers are designed for jump starting, but might be too much for a smallish bike battery. Better get the booster mate, they're a very handy device. Cheers, Terry.

Ah well - I am off to Autobarn in Elizabeth street at lunch time then!

[Terry in Australia]

It depends on the charger Cliff, some of the new high amperage chargers are designed for jump starting, but might be too much for a smallish bike battery. Better get the booster mate, they're a very handy device. Cheers, Terry.

Ah well - I am off to Autobarn in Elizabeth street at lunch time then!

Good idea mate, and don't buy a real big expensive one, I just bought the cheapest (over a year ago now) and it'll do everything I need, and my son takes it in his 4WD when he goes to the snow. I bought my Dad a much more expensive one with a built in air compressor which is handy, but not worth the extra 150 bucks I paid for his. Cheers, Terry.

[maduncle]

I went for a ride tonight!

Got home and fitted the battery, along with the connector for the charger/booster. So now I have a permanent lead I can plug into hidden away under the seat and easy to access. Pulled spark plug one lead off and went to pull out a plug, only to find I did not have the socket to fit!

So I left the plug in and got on with turning the bike over, tried it on no choke, then a bit of choke, then full choke, then I saw the fuel running out of the bottom of Tintop's filter set up!

Then I realised I had not put the lead back on the plug!!!

So I put the lead on and the bike started. Gave it a good slow warm up time, which helped to bake the header paint on (temporary paint job until I get them ceramic coated). Blew a bit of old carbon out of the pipes at first and then ran clean.

Jumped on and took it up the street. Great news is that the rear sets work fine, good positioning and the gear changes are easy. Gave the rear brake a good press and pulled up sharp first time. Only problem was gave the rear brake another good press and did not stop!

So back to base - checked the rear brakes and found the banjo on the brake master cylinder was loose. Tightened it up, bled the brake and refilled the fluid. Went for another ride and everything works!!!

Next step is the final tune, probably end up at a local place called T-Rex racing (they come recommended for dyno tuning).

This is one  happy CB750 rider!

Oh, and here is how the new pipes and muffler and Tintop's filter set up look.

[Syscrush]

Very cool.  Those are exciting milestones.

[maduncle]

Thanks Syscrush - the final part of this "phase one" build is to get it tuned up with the right jets, running on all four smoothly and starting easy.

Not too much to ask is it?

Then I will be spending my tinker time on the CB450 Black Bomber rebuild...

(See the "other bikes" thread).

UPDATE:

Okay - having spent time on the phone with well known race mechanics, and time talking to well known forum addicts (Terry!) I have faced up to the fact that there is no real point blowing $400 on dyno tuning my stock carbs, when I could put that money aside and save up for some CR29's. So that is the plan now - ride it as is and put some much better carbs on it when I can afford them.

... whilst also building the bomber.

[maduncle]

F*#ckin stock carbs!!!

I took the bike out tonight and is is sluggish off the start, choppy in mid range and sings once it is over 6000rpm. So I know it can go.

Come to a stop in traffic and I reckon I dump half a tank of fuel through the overflow lines off the carbs!

And it is all out of line 2, off carb 2.

And I don't mean drips, I mean it streams out (I couldn't piss that hard after 24 beers).

So - I can't take this bike anywhere without being followed by a fire truck (which is ironic given my job) and without being followed by a fuel tanker to refuel me after 1/2 hour on the road!

I will try tapping carb 2 so see if the float needs dislodging - apart from that I am going to patiently wait for a set of CR's.

GRRRRR.


And if anyone out there could advise me on the correct jet sizes for a set of CR29's on a stock CB750F engine running K&N filters - I would appreciate it.

I would have liked to have kept Tintop's filter set on the bike, but it fits my stock carbs.

[maduncle]

I have found another carb option.

http://www.wgcarbs.com//index.php?option=com_content&task=view&id=14&Itemid=29

I have spoken with them via email and I can get a set of their VM30's (modified 26's) and adaptor boots for my bike.

Interesting...

[maduncle]

Evening all,

I am looking for opinions, thoughts, advice, ideas and any other comments on which carb to get to put on the 4 into 1 POSA manifold I am going to try on the bike, just to see what it is like.

Now, before you say something like "stick with 4 carbs, get CR's" etc - I will probably end up doing that at some later stage - but the "idea" of the POSA manifold and one carb appeals to me (yeah, I am slightly mad - hence my forum name) so I want to try it out to see how it goes. If I like it and I don't mind any performance loss then that's fine by me as I casually cruise around the city. If I want screaming performance then I will have to go back to four carbs.

So with the POSA set up,  - which carb to get?

I am tending towards a Mikuni over a Keihin (The Keihin Harley CV carb could work...), the thing is I would not know the difference between a Mikuni TM or a VM (or an HSR for that matter), and whether I need a "throttle actuated accelerator pump" on the carb or not.

And which size? The manifold can handle a carb up to 40mm, but do I need to go that big?

There are plenty of Mikuni carb options out there and the seller on eBay called Niche Cycle Supply has a good range.

So if anyone can offer me any suggestions - I would welcome adding your advice to the pool (or in my case - puddle).

UPDATE: Having just read several lengthy threads on the many reasons not to use a log manifold on a SOHC4 engine when a 4 carb set up is so much better for the bike, please understand I accept all of that but this is just something I would like to try for myself and learn from.

[Syscrush]

I would say don't go half way.  Get a Lectron (based on the design of the old POSA "injector"/carburetor)!