Topic: 1973 CB350F "Modest Original" build

[iiAtlas]

Good looking  Vintage Honda's Atlas ! 

The 'Word'-is-out now to folks around there that you're restoring bikes  and you'll be able to go into business for yourself,part time.. 

Now I just have to finish something... 

[iiAtlas]

We managed to get the CL350 back on the road and I took her for a spin.  This was the first of similar vintage 350 Honda's I'd ridden and WOW ! What a blast.  I am really inspired to get my 350F back on the road.  I absolutely love the dimensions of these things!

[grcamna2]

Nice looking Honda Atlas and a good size for the city.

[iiAtlas]

Nice looking Honda Atlas and a good size for the city.

Absolutely PERFECT for the city!  What a dream 

[MoMo]

good job Atlas...Larry

[iiAtlas]

Update time!  The CL turned into a larger project than I'd hoped.  After a quick tune up (valves, cam chain tensioner, points, plugs, carb's to base settings) she kicked over good and idled happily but was only running on one cylinder (the left).  We popped off the float bowl et voila, no fuel to the right carb.  Blockage wasn't in the lines but rather in the carbs so we got to work.

This bike, cool as she looks, is a pain to work on.  To get the carbs or even the airbox off you have to remove the entire exhaust system!  Any attempts to do remove either without fully dismantling the exhaust will be futile...ask me how I know...





The carbs told an interesting story.  One side, the good side, had the original Honda brass float.  This one aged well and didn't show any extreme buildup or wear.  The bad side however had the wrong model float installed and was covered in varnish-like gas. 



(Bad - RH)


(Good - LH)


Into the parts cleaner they went!







They cleaned up well, but as I lay everything out to begin rebuilding (or seeing what I would need to rebuild) more discrepancies came to light.  The bad side (RH) carb not only had the wrong model float, but the wrong size and non-keihin jets.  The LH side had the factory Keihin jets and to spec sizes.  This bike is all stock so I doubt this was on purpose.  I presume it was an attempt at a rebuild without the right rebuild kit.  Sadly, both sides had pretty iffy brass so I ended up ordering a new set of stock jets for both.  The final parts list looked like this....



I later learnt this bikes didn't use a regular oil filter but rather had a centrifugal system which would require cleaning -- cool! 

Some parts arrived today but not the rebuild kit, that will hopefully be here this week then we should be able to get this ol girl back on the road!



--

As for my 350 Four I am keen to finish her.  I think I'm a little hung up on the engine.  There are a lot of parts in there, some big and some small, and a lot to clean.  Every time I look at my "to-do" pile I get nauseous!  I've decided to take a step back and tackle something I can complete, the wheels.





I have the spokes in the parts cleaner and I will be priming and spraying the rims black.  I bought a high temp high strength epoxy spray paint (at something crazy like $30 a can...) which I hope will hold up.  If not they will go to get powder coated, but I figure I should try this first.  Wish me luck!

[grcamna2]

Atlas,
The CL is getting some needed care  The oem floats are fairly easy to get.I hope you get oem ' brass' into the carb. that didn't have it so it matches the other side exactly,be careful what parts they send to you.

[iiAtlas]

Atlas,
The CL is getting some needed care  The oem floats are fairly easy to get.I hope you get oem ' brass' into the carb. that didn't have it so it matches the other side exactly,be careful what parts they send to you.

Yes they were surprisingly easy to get!  And look great too, nice.  OEM brass not as easy.  I've ordered the highest quality rebuild kit I could find.  I'll be doing both carbs so that they will once again match!

[iiAtlas]

Progress!  Spokes done:



I have ordered a higher quality organic vapor respirator before I continue  (3M 7500 Series) Sick of breathing in these fumes! Even with the parts cleaner.  Will be good before I spray too.  I know some of you are against the black rims but I figure it's my best best at restoring these.  I'll start with a 220 grit sanding, then a a high temp/high strength epoxy spray.  If this doesn't hold up I'll go with getting them powder coated, and if I had the black consider getting them rechromed/nickel plated.

Happy Thanksgiving to you all!

[calj737]

I doubt 220 grit be sufficient to mechanically bond the paint to the chrome. Might start lower, then use a primer to bond. Then paint.

[iiAtlas]

I doubt 220 grit be sufficient to mechanically bond the paint to the chrome. Might start lower, then use a primer to bond. Then paint.

Okay thanks for the tips.  The paint (VHT High Temp epoxy) says self priming.  I have some very pricy epoxy primer (spray max 2k) which I was saving for the frame but I bet that would do great.  Also have a standard rustoleum sandable auto primer - do you think that would be sufficient?  Again the paint says "Self priming" so I'd imagine using the wrong primer would be doubly unproductive.

[nvr2old]

Chrome is such a hard surface.  Sanding it is almost impossible.  If you can sandblast them at this point, as the spokes are not in them, it would be the perfect time to do so.  I've had great success after blasting, priming and then painting them...not so much after trying to sand the chrome.

[MoMo]

self-etching primer should help after scuffing as much as possible

[nvr2old]

It's really difficult to get paint to stick to chrome if it isn't fully prepped, especially around the bead and spoke holes.  The self-etching primer is a good choice, but it won't help the paint stick, if the chrome doesn't have the correct surface to adhere to.  Every spec of the chrome has to have the shine gone otherwise the primer/paint will not adhere.  It will chip or flake wherever it wasn't.

[grcamna2]

Chrome is such a hard surface.  Sanding it is almost impossible.  If you can sandblast them at this point, as the spokes are not in them, it would be the perfect time to do so.  I've had great success after blasting, priming and then painting them...not so much after trying to sand the chrome.

+1 on the sandblasting,you probably wouldn't even need the first coat of primer w/ that special epoxy paint.

[iiAtlas]

Chrome is such a hard surface.  Sanding it is almost impossible.  If you can sandblast them at this point, as the spokes are not in them, it would be the perfect time to do so.  I've had great success after blasting, priming and then painting them...not so much after trying to sand the chrome.

self-etching primer should help after scuffing as much as possible

It's really difficult to get paint to stick to chrome if it isn't fully prepped, especially around the bead and spoke holes.  The self-etching primer is a good choice, but it won't help the paint stick, if the chrome doesn't have the correct surface to adhere to.  Every spec of the chrome has to have the shine gone otherwise the primer/paint will not adhere.  It will chip or flake wherever it wasn't.

Chrome is such a hard surface.  Sanding it is almost impossible.  If you can sandblast them at this point, as the spokes are not in them, it would be the perfect time to do so.  I've had great success after blasting, priming and then painting them...not so much after trying to sand the chrome.

+1 on the sandblasting,you probably wouldn't even need the first coat of primer w/ that special epoxy paint.

Thanks for all the good input you guys.  If I go the sandblasting route I would most likely just continue on and powder coat.  Nvr2old sounds like you have significant experience with this, appreciate the words of wisdom!

I may put these on hold and leave the spraying for the non-chromed parts.

[grcamna2]

Atlas,
The powder coating is always best and will last much longer than paint. 

[iiAtlas]

Continuing the off topic trend but not for long (I promise)..the CL350 is rebuilt.  The carbs came out nicely.





I opted to replace both sets of jets, even though one was original Keihin, because I thought it better than a mismatch.  Sadly the jets in the rebuild kit were not the same as the original 722A Carb sizes.



Instead of #35 slow, #68 second, and #105 main we are running #38 slow, #70 second and #105 main.  What exactly would an increase on the second and slow jet result in?  Apart from that I set both floats for 26mm and the pilot screw 1 1/8 turns out.  She's purring like a kitten!



...for the most part...she runs great on the low end, but tops out loaded at 5k rpms.  Puttering, no power.  Very zippy below that!  But will not go above.  In neutral, unloaded, she will rev up to 7k+ without much hesitation.  Thoughts?  My initial guess was float height, maybe it is starving for fuel at the upper power ranges.  Now I'm thinking could be jets.  Will do a plug chop and see how they are looking around that range hopefully today or tomorrow. 

Wanted to get all of your input before I dug into the bike again!  A real pain to get to these carbs with the high exhaust and all...

Thanks!!

[MoMo]

what is the air filter situation Atlas? ...Larry

[iiAtlas]

what is the air filter situation Atlas? ...Larry

Ah the air filter, another IMPOSSIBLE part to remove with these high pipes!  The air filter is OEM but dusty.  New ones are $120 for two and not even OEM!  I tried to blow it out but maybe that was not enough...should've known better...wish I had a picture but no luck.

http://www.common-motor.com/honda-cb350-air-filter

Do you think that could be it?  Starving for air at high revs, sounds possible.  Thanks Larry!

[MoMo]

First thing I thought of, and they sure are a pain on the CL model.  Good luck

[iiAtlas]

First thing I thought of, and they sure are a pain on the CL model.  Good luck

Thanks for the tip..wish I would've headed it before putting the whole thing back together!! I will order the new filters...

[iiAtlas]

Ordering new filters from 4into1 and the correct 722a jet sizes.

[iiAtlas]

Filters arrived last night and we got to work!  Off goes everything YET AGAIN, damn these high pipes...



Take a look at the comparison.  These OEM replacements were a good buy!



Installation time: 3 minutes
Time to reach air filters: 35 minutes

Installed factory jets, #68 primary #105 secondary, #35 slow



And set float heights to 26mm with this nifty tool.



I used my calipers to adjust the height accurately to 26mm, then just used the tool to consistently repeat the measurement.  I am confident these are now 26mm+/-0.5mm as per the 722A specification.  Air screw set to factory 1 1/8 turns out.

We put the bike back together and she kicked right over.  Still running great down low.

Sadly, she STILL will not pass 5k RPMS.  Hopefully this video will help explain...

This was after the engine was warm and running well.  Looking at the plugs they are rich (new B8ES, gapped to .026").  As per the book the air screw must remain 1/8 to 1/4 within 1 1/8 turns out at final setting.  I have a feeling even at 1 1/2 or 1 3/4 out we will still be too rich.  Could float height be an issue?

Thank you all for the input!  I know this isn't a 4 banger but I appreciate the help.

[grcamna2]

Atlas,
How did it run before the work? Did you change anything inside the points cover,cam chain/valve adj. ?