Topic: CB750 K4 Build - The Cafe Tracer

[budman]

Simply beautiful, Bud!   

What main jets do you plan to use with that airbox and exhaust?

What else is needed to fire her up?!

Thanks, Steve.  I ordered a spec'd jet kit and for the first attempt they recommended 115's for the two outside carbs and 117.5's for the two inside carbs.  If it's too lean they said to move the 117.5's to the outside and use 120's on the inside.

I need to redo one of the oil lines.  It leaks.  I didn't have enough line up inside the compression fitting to get a proper seal.  After that I think all I need is gas.  My sync gauges and IV bottle arrived yesterday.  Unfortunately, or depending how you look at it, it's my son's 18th birthday on Sunday.  I'm taking him to the Lone Star Throwdown Truck show in Conroe tomorrow and doing the birthday thing on Sunday.  I probably won't get to do much on the bike until next weekend, but I'm supposed to go on a ride that Sunday.  I still need to polish the gas tank.  I'll get there.

[Stev-o]

Simply beautiful, Bud!   

What main jets do you plan to use with that airbox and exhaust?

What else is needed to fire her up?!

Thanks, Steve.  I ordered a spec'd jet kit and for the first attempt they recommended 115's for the two outside carbs and 117.5's for the two inside carbs.  If it's too lean they said to move the 117.5's to the outside and use 120's on the inside.

I need to redo one of the oil lines.  It leaks.  I didn't have enough line up inside the compression fitting to get a proper seal.  After that I think all I need is gas.  My sync gauges and IV bottle arrived yesterday.  Unfortunately, or depending how you look at it, it's my son's 18th birthday on Sunday.  I'm taking him to the Lone Star Throwdown Truck show in Conroe tomorrow and doing the birthday thing on Sunday.  I probably won't get to do much on the bike until next weekend, but I'm supposed to go on a ride that Sunday.  I still need to polish the gas tank.  I'll get there.

You've only been working on this 2.5 years, what's another month or two?!

FYI - I changed the jetting on the Park Racer a couple times, it's got 115's now and seems right. 

[budman]

You've only been working on this 2.5 years, what's another month or two?!

FYI - I changed the jetting on the Park Racer a couple times, it's got 115's now and seems right.

Good to know about the jets.  The engine is basically stock except for the bolt on stuff.

I'm in no hurry.  I'm just trying to make everything as right as I can before the first fire up.  Any pointers you can give for that first start?

[Stev-o]

You've only been working on this 2.5 years, what's another month or two?!

FYI - I changed the jetting on the Park Racer a couple times, it's got 115's now and seems right.

Good to know about the jets.  The engine is basically stock except for the bolt on stuff.

I'm in no hurry.  I'm just trying to make everything as right as I can before the first fire up.  Any pointers you can give for that first start?

Basically stock except for the most important things for jetting: intake and exhaust.

Before start up, be sure you are getting oil to the top end.  Crank it with the kill switch off [if possible], pull your valve adj caps and look for oil there. Good luck!

[budman]

I couldn't get the stainless steel oil lines exactly like I wanted.  Tired of messing with it.  Those stainless lines are very unforgiving.  For now I'm going to run hose.  Maybe someday I'll revisit it...maybe with copper.

I'm going to try to start the bike for the first time on Saturday.  Fingers crossed.

[Stev-o]

Sorry to hear the ss lines didn't work out. 

Good luck on the start up!

[budman]

Sorry to hear the ss lines didn't work out. 

Good luck on the start up!

Thanks, Steve.  It's all an experiment so if that's the worst of it I'll take it.  I noticed the oil lines on the Park Racer.  Don't look stock.  Where'd they come from?

[Stev-o]

Sorry to hear the ss lines didn't work out. 

Good luck on the start up!

Thanks, Steve.  It's all an experiment so if that's the worst of it I'll take it.  I noticed the oil lines on the Park Racer.  Don't look stock.  Where'd they come from?

Not stock, but they are an upgraded stock line done by forum member Mo.   He zinc coated the fittings and fitted new ss hoses.   He made a limited amount of these for us. 

[budman]

Not stock, but they are an upgraded stock line done by forum member Mo.   He zinc coated the fittings and fitted new ss hoses.   He made a limited amount of these for us.

Cool.  They look great.

[budman]

Ladies and gentlemen, she has a heartbeat.

[budman]

I started the bike for the first time yesterday.  The first attempt didn't work because the battery was too weak from testing the different circuits during the wiring phase.  A few hours on the charger and the engine fired right up.  After it warmed up I messed with the timing and ran it for about 20 minutes at different speeds.  Everything appears to be OK.  Got oil pressure.  It's charging.  Kill switch works.  It was a great day.

I'm waiting on the airbox to get back from the powder coater before I attempt to sync the carbs.  Hoping it will be ready this week.  I'm hoping to have the gas tank polished today.  Would love to take a test ride at least up and down the street before spring break.

[Stev-o]

Congrats, Bud!   Great feeling that first start up is.

BTW - use a fan blowing on the cylinders when running the motor on the lift. 

[budman]

Congrats, Bud!   Great feeling that first start up is.

BTW - use a fan blowing on the cylinders when running the motor on the lift.

Thanks, Steve.  Had the fan going the whole time.

[palepainter]

Congrats Bud.  I'm sure that had to be a great feeling!!!

[budman]

Congrats Bud.  I'm sure that had to be a great feeling!!!

Thanks, Mike.  Was a great feeling, especially after the engine tear down.

[markreimer]

Video!!!!!!


Sent from my iPhone using Tapatalk

[budman]

Video!!!!!!

Got one, but can't figure out how to upload it via Tapatalk.

[markreimer]

Been having that same issue for the last two weeks or so. It's like the video upload button was removed from the app or something.

[budman]

Been having that same issue for the last two weeks or so. It's like the video upload button was removed from the app or something.

On 2/28 they claimed to be upgrading the video upload server.

[budman]

Got home from work tonight and fired up the CB750 just to make sure Saturday wasn't a dream. 

Had to add some oil now that the engine's been cycling.  Holding good pressure.  Found a small leak.  Thought it was the valve cover but I think it's the tach plug.  Gotta stuff some sealant in there or something.

I also jacked up the back of the bike and went through all the gears a few times.  Shifted smoothly.  Clutch is working great.

It all looks promising.  Sure wish the powder coater would get my airbox done though.

I didn't get to finish up the tank yesterday.  Was raining cats, dogs and a few other animals  yesterday and I couldn't take the noise of the rain on the metal roof.  Gotta find some time this week to get that done.

[SOHC4 Cafe Racer Fan]

If you have a tach plug, it might be missing an o-ring.  Don't put RVT on it.

[budman]

If you have a tach plug, it might be missing an o-ring.  Don't put RVT on it.

Has an o-ring.  Must be a bad fit.  Probably use some Three-bond.

[budman]

Fixed the leak at the tach plug with some Three-bond.  The O-ring is way too thin in my opinion.  Needs to be fatter with more surface area contact.

But now I've detected a leak at the neutral safety switch.  That's the one O-ring I did not change.  For whatever reason I did not pull the switch out.  I can't recall my reasoning.  Looks like I've got to deal with it now.

[MauiK3]

Looks wonderful, what a build. And thank you for your help with my slow moving project. As I move through I am discovering many small problems, none of which are very big. I replaced the ignition and air box which really made a difference. When I "analyze " it enough the motor will come out for freshening up.
By the way, your valve cover is beautiful. Is it all just hand polished? Did you coat it with anything? Also, did you fiat the engine block? Sorry if it's in the posts somewhere, I admit I have not read the entire string.
Steve

[budman]

Looks wonderful, what a build. And thank you for your help with my slow moving project. As I move through I am discovering many small problems, none of which are very big. I replaced the ignition and air box which really made a difference. When I "analyze " it enough the motor will come out for freshening up.
By the way, your valve cover is beautiful. Is it all just hand polished? Did you coat it with anything? Also, did you fiat the engine block? Sorry if it's in the posts somewhere, I admit I have not read the entire string.
Steve

Thanks, Steve.

I had the valve cover and all the engine covers chrome plated.  I didn't want to spend the time polishing or maintaining the factory aluminum.  I do enough of that on my other bike.

The silver head and the gun metal cases are painted with a metallic single stage acrylic urethane.  They were supposed to come out glossy, but looks more like a semi gloss.  The cylinders are painted with the same gloss black urethane I used on the frame and most of the rest of the black parts you see on the bike.

Did you find your points screws?