"Patina" The 1973 CB175 Cafe Racer

Success!

I threw everything together quickly, tossed on my old cb175 headers and she fired right up. No leaks from the bottom end so far.

Here's a video of an idle when I couldn't figure out why it wouldn't rev (forgot the choke was on)

http://youtu.be/khBW0kQHvm0

And here's a video of the choke off (ignore the first handful of kicks and fastforward to the end)

http://youtu.be/11eP05uQdvc
 
Re: "Patina" The 1973 CB175 Cafe Racer

Kinda strange it likes to start on choke, doesn't stay running on choke, revs without choke, will die without choke and no throttle. Short pipes prolly have something to do with it - plugs are black and wet after a few revs, no filters.
 
Re: "Patina" The 1973 CB175 Cafe Racer

CHARGING for the first time with the new stator.

bf7805fcabd29655c3b8558e89a74817.jpg
 
Re: "Patina" The 1973 CB175 Cafe Racer

Looks good Greyson. Have you checked your timing with a light?


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Re: "Patina" The 1973 CB175 Cafe Racer


Texasstar said:
Looks good Greyson. Have you checked your timing with a light?


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Click to expand...

Yeah I have - a few times. I'm falling right between the full advance marks at 4k RPMs or so. Now it will be a lot easier to check timing with a kickstarter since I don't have to hold the timing light in my teeth with it connected to the battery and spark plug wire to jump start it haha.

According to my EI instructions, the static timing is "correct" which doesn't matter much, and the advance timing is good as well.

I'm going to put the CL exhaust back on and try to get it back down the road to see if the carb cleaning helped my poor running situation.
 
Re: "Patina" The 1973 CB175 Cafe Racer

So far I'm having a hard time figuring it out. Only starts with full choke but won't rev with choke. Will rev without choke but backfires really badly.
 
Re: "Patina" The 1973 CB175 Cafe Racer

Tim had to reset everything this morning and a bunch of posts were lost...I was looking for them also


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Re: "Patina" The 1973 CB175 Cafe Racer


Texasstar said:
Tim had to reset everything this morning and a bunch of posts were lost...I was looking for them also


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Click to expand...

Oh ok I gotcha
 
Re: "Patina" The 1973 CB175 Cafe Racer

Did you figure it out?


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Re: "Patina" The 1973 CB175 Cafe Racer


teazer said:
Too lean?

Air leak?

Lack of mufflers will also cause odd running effects
Click to expand...

Teazer, not sure. Plugs are new and wet/black. Don't yell at me for not doing a proper chop. Before the post got deleted, Sonreir suggested adding a drop of gas to each cylinder through the plug hole and seeing if it runs better.

I can't be too far off because my jetting is Stock other than the main, air screw is 1.5 from bottom and idle mixture is 4.5 from bottom.

I'm hoping the "mechanic" didn't forget that oring up the oil passage.
 
Wet and black sounds rich but was that from running with the choke on or off? Needs choke to start = lean, but Hondas of that era were always cold blooded and needed choke and mufflers.

I'd slip on some mufflers and see if it fires up on choke and revs with choke off. Keihin choke almost strangles the motor when the steel flap is down cutting off air. It can't breathe like that and also needs to warm up a bit before it will rev out cleanly.
 
Re: "Patina" The 1973 CB175 Cafe Racer

We did have it backfire once when we didn't have the carbs tight.


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Okay! Update... she was real cold, i mean like 25 kicks kind of cold. Choke ON, started up with throttle. Held it there to warm it up. Would not run with choke after warm. During the startup process I got one nasty pop with flame through the velocity stack.

While still kinda warm, not hot, revs around mid throttle about 5k was REAL sluggish. After warm, revved fine upwards of 7k. Could have gone further but too many things were vibrating and sounding like it was going to blow up in my face.

Couldn't get it to idle right. It would die if I didn't hold the throttle. So I turned the idle air screw in 3/4 turn and it held a high idle. If I backed back off the idle air screw, it would just about die, I would blip the throttle, it would jump back up to 2500 and hold for a few seconds, then gradually fall back down.

FYI, checked the carbs, they were tight...radiator hose connection was tight to the carb inlet too.

It ran a slight bit better with the UNI I stuck on there at the last second.

Here it is running (better).

http://youtu.be/iLjbkwcZT_I
 
Re: "Patina" The 1973 CB175 Cafe Racer

That sounds good. Do you still have your mechanical advance?


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What rpm are you looking to idle at? Aren't the stacks going to limit your tuned rpm range, depending on their lenght
 
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