Author Topic: Spiider's '73 CB750 - "The Baby Elephant" (Read 40847 times)

mrbreeze · « **Reply #75 on:** August 14, 2011, 04:55:58 PM »

Itchin' to see how that air box performs. Let us know

Spiider · « **Reply #76 on:** August 14, 2011, 05:06:24 PM »

Me too...in theory it should be similar to the "antipod" project from here.

It doesn't have velocity stacks "built in", and the filtered area is shared between all 4 carbs so the pressure should be equal and not as susceptible to crosswinds like pods are.

We'll know soon...once the exhaust gets here I believe I'm ready to test ride.
After that, paint....and then she is "done".

Well, there may still be future improvements...

Retro Rocket · « **Reply #77 on:** August 15, 2011, 03:10:38 AM »

Quote

Me too...in theory it should be similar to the "antipod" project from here.

I like the look of that airbox but jf it doesn't have velocity stacks it won't be anything like Tintops Antipod.....The whole reason Tintop's works is because of the stacks, the Antipod is tested to flow 300+ HP so should be good for a fire breathing/4.

Spiider · « **Reply #78 on:** August 15, 2011, 09:36:39 AM »

Well, I haven't changed the filter yet...and considering Steel Dragon seems to be primarily a velocity stack manufacturer...we'll see. I guess there is some way they feed the air from the box to the carbs that is similar to a velocity stack.

I looked at the antipod initially but at least imo the price is really excessive...and it's ugly.

Spiider · « **Reply #79 on:** September 04, 2011, 09:20:31 AM »

Well, I got my Lossa stainless 4-1 exhaust on Friday..threw it on with new honda copper exhaust donuts.
At first I was concerned because the fitment was kind of crappy but as it got bolted down things started coming together.

It's still too close to my spin on oil filter with the Randakk adapter...if I change the filter it looks like I will have to pull the exhaust.

For the most part I should only have to do that once a season, I won't get to ride more than one tune up a year anyway.

The exhaust is on with no leaks and sounds amazing. My neighbors across the street can't be happy this morning.

I spent the morning setting my timing with a timing light...I got the Daichi points plate set up very nicely but I have a OEM honda one on the way as well to replace it.

I also pulled out the Morgan carb tune and spent some time getting the carbs all sync'ed up...it certainly runs nicer when the timing is set and the carbs are sync'ed.

After this it's time for paint, and she's ready to ride.

www.jeffreid.ca/cb750/cb750startup.wmv

surein · « **Reply #80 on:** September 16, 2011, 08:06:13 PM »

Beautiful build and write up. Hope to get there one day. Thanks for the tips and tricks

Spiider · « **Reply #81 on:** September 18, 2011, 02:55:47 PM »

Thanks!

Just an update/question....

The bike has been running rich when idling and popping in the exhaust etc., I set the idle air screws to 1 1/2 turns out.
I've checked the float height it measures good.

The carbs are clean etc...I set my timing via the static method to rough it in then fine tuned it with a timing light.

It starts ok, needs some warm up but I think that's normal for these bikes.

I pulled the plugs today and they are black with soot. And here is the interesting part...they are NGK DR8ES-L!

But I have NGK 5kOhm resistor caps as well!

So, I threw in a set of NGK D8EA's and she runs a lot better actually and doesn't blow white smoke much at all.

Am I right in thinking the P.O. screwed up with these plugs in the bike? Resistor plugs and resistor caps together?
Or doesn't it matter much?

I will know more about the airbox once I get it out on a windy day.
The airbox has worked out perfectly for tuning though...no issues at all so far.
The bike certainly hasn't "leaned out" from it anyway.

I'd say it's an excellent option for guys like me that were missing the airbox because a P.O. liked pods.

Free Booter · « **Reply #82 on:** September 19, 2011, 09:56:29 PM »

Quote from: Spiider on August 14, 2011, 04:35:49 PM

Updates...used carbs from "GnarlyCharlie"
Custom Speedo, Tach and Push/Pull cables (-5 inch from MotionPro)
Steel Dragon airbox with UNI filter.

Update to follow when my Lossa Exhaust arrives, they said it should have shipped Monday...we'll see.

Damn it man1 I'm going to have to put thicker tinfoil on my head! That's the same airbox I've been staring at for a year! (OR MONTHS? i FORGET.., but seriously!? At least now I know what it will "may" look like. thanks! MUWahahahahahahah!

Free Booter · « **Reply #83 on:** September 19, 2011, 09:59:32 PM »

Also...where did you get your fork mount turn signal brackets? I've been looking for a set everywhere for 35mm tubes.

Spiider · « **Reply #84 on:** September 20, 2011, 03:59:46 AM »

The turn signal brackets are a Kuryakin part for Harley's with 35mm tubes that I modified.

I had to tap the hole with the correct thread to fit the turn signal posts.
They came drilled, but the diameter was perfect for tapping the thread I needed into them.

Then I had to mill a spot for the wire to come out the bottom where it can't be seen easily.

I searched high and low to find something non-Harley but they simply have the best custom parts available....

The Steel Dragon airbox is great so far. Very happy with it.
They were good guys to deal with although if I remember correctly it took a few weeks to get as they had to make it for me.
You can also get them powder coated in a custom color if you want to pay for it. I just got the black powder as it matched my frame, headlight bucket etc.

lucky · « **Reply #85 on:** September 20, 2011, 07:46:44 PM »

If the gas tank is leaking at all do not ride it!!!
A fire can start very easily on a motorcycle.

With pod filters and 4 into 1 exhaust I would try a #120 main jet.
That size was recommended to me by the company that sold me my pod filters.
If you put the choke and an it would not run it means the idle jets are clogged up.
At idle up to 1/4 throttle the engine runs on idle jets and air/fuel adjustment screw.

Spiider · « **Reply #86 on:** September 22, 2011, 04:35:40 PM »

Gas tank is perfect....no leaks, just needs paint.

I got rid of the pods and went with the Steel Dragon airbox, but I did stay with the 4/1.

However, my problem now is that I was running rich with the resistor caps AND resistor plugs in the bike from the previous owner.

I've now got the D8EA's in there and it runs better, and the exhaust doesn't smell like unburnt fuel.

I'm getting the idea that it needs less fuel at this point.
I have no idea what jets were in the carbs as I bought them used/rebuilt.

I hope stock ones, but I guess I better buy some to make sure.

deebz · « **Reply #87 on:** September 22, 2011, 10:17:59 PM »

What happened to the Carpy 4-1??? I was thinking about ordering one.....I was also looking at Lossa but after reading about the oil filter thing I think I'm gonna pass.. your bike looks great, good work.

Spiider · « **Reply #88 on:** September 24, 2011, 04:54:22 PM »

The Carpy 4/1 is a story all in itself...I ordered, waited patiently for 2 months....it never came,never came, never came...I was patient some more...I sent a few emails...and it turned out he was switching manufacturers...lost/forgot my order somehow...then promptly refunded my money.

I ordered from Lossa the next day...that has turned out bad but in a different way.
It came, fitment is poor and now they won't return my emails about solving issues.
I had to basically move pipes for two and three with a ratchet strap just to fit.
Still have a tiny bit of leaking too...but not at the header, just a tiny puff at the slip-on under throttle.

So, just take it for what it worth...you spend $500 and you are basically on your own I guess.

Next exhaust will be from Yamiya I'm guessing.

I think all these guys are essentially the same...Carpy, Lossa, MotoGP.

Busy busy busy but happy to take your money, oh and don't bug them afterwards when they don't deliver or you think their stuff is questionable quality. $:-\$

deebz · « **Reply #89 on:** September 25, 2011, 02:33:06 AM »

Damn that sucks dude....what does a guy do?? All I want is a quality affordable 4-1 that bolts right on, is that too much to ask???

Spiider · « **Reply #90 on:** September 25, 2011, 12:11:42 PM »

Quote from: deebz on September 25, 2011, 02:33:06 AM

Damn that sucks dude....what does a guy do?? All I want is a quality affordable 4-1 that bolts right on, is that too much to ask???

Apparently it is too much to ask...for 500$ I thought it should fit like OEM, it didn't.

I may buy another exhaust yet...it depends on how this one works out over the next year.

FrankenFrankenstuff · « **Reply #91 on:** September 25, 2011, 05:02:42 PM »

http://forums.sohc4.net/index.php?topic=93404.0
This is where the seat and tank ended up.

Spiider · « **Reply #92 on:** September 26, 2011, 03:30:47 AM »

I've been keeping an eye on that build because of that!
Seems strange to see the seat and tank on another bike...

You can see it in the first pics of this build when I picked up the bike.

Spiider · « **Reply #93 on:** September 27, 2011, 04:01:42 AM »

And last night...a setback...but life is about small setbacks right?

I was tuning and retuning the bike on the weekend and haven't been able to get an idle stumble worked out.

Then I found that 4, 3, and 1 were leaking gas at various amounts but steadily from the overflows.

So, I started pulling bowls...and found the valve seats were about finger tight and still dripping around the seat when the float was held up...no biggie, I can handle this easily.

I went around and started removing the bowls and floats tightening the seats up a touch more, 3 and 4 went ok...went around to the other side of the bike and pulled #1 bowl off...to find one side of the float dangling down a bit...broken float pivot post.

Now I'm dead in the water until I get a new #1 carb body...or take it all apart to try and get it micro welded.

*Sigh*

Maybe I'll try to find a spare rack to steal parts from...but I think micro welding is the "easy" route now.

The carbs were all set up and working perfectly other than a rich exhaust, which is what I was trying to fix by giving it a valve adjustment and tune up in the first place.

70CB750 · « **Reply #94 on:** September 27, 2011, 04:15:59 AM »

That air box looks good, nice clean installation too!

dagersh · « **Reply #95 on:** September 27, 2011, 12:10:07 PM »

Spiider,

Great build! Let's see some more pics of the pipes. They sound fantastic!

Good luck with the carb float post - its a PITA, but a microweld will save the day.

Dagersh

Spiider · « **Reply #96 on:** September 27, 2011, 04:28:34 PM »

I guess I've got to find someone who can do microwelding locally...without destroying the pot metal the carb bodies are made of.

Spiider · « **Reply #97 on:** September 29, 2011, 03:56:14 PM »

Still no word on someone who can do a microweld for me...

But, to cheer me up some parts arrived from Joker Machine!!!

Oil pressure gauge, and kick start cover...both very nice fitment and I think they look great!

Here you can see the Joker brake bar, and the rear axle clip pin. (And the silencer/outlet on the Lossa exhaust.)

Some pics of the Lossa pipes as requested!

lucky · « **Reply #98 on:** September 29, 2011, 04:04:46 PM »

If you strike an arc with a TIG torch on AC high frequency and it glows green it means that alloy has a high zink content. Like weed eater engine cases.

They sell special filler wires at welding supply houses for that metal.
If it glows red or blue you can use 4042 welding filler wire like with aluminum.
You will need someone who is really good at TIG, and depending on what needs repair it may not be repairable. I wish you had posted a photo of the damaged part.

Spiider · « **Reply #99 on:** September 29, 2011, 04:23:58 PM »

I'll try to get a pic of the snapped off part up asap, I appreciate any advice on it I can get.

Oh, and I almost forgot the coolest item of all arrived yesterday!
My Bell500 and flip shield!!!

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Author Topic: Spiider's '73 CB750 - "The Baby Elephant" (Read 40847 times)