1971 Honda CB350 Restore/Tune-up

I bought a 1971 CB350 10/17/2015. It only has a little over 4300 miles on it. Got it running (sort of), but I want it running great! I'll post updates (with pics) as I go. I appreciate any advice!

cool dude. welcome

There we go! I've got a CL350 basket here (71') so I'll give you any help I can since they are basically the same thing Just got her running from sitting in the previous owners garage since 1977...heh.

MotorbikeBruno said:

There we go! I've got a CL350 basket here (71') so I'll give you any help I can since they are basically the same thing Just got her running from sitting in the previous owners garage since 1977...heh.

Click to expand...

I can tell your from the northern states when you haul bikes home on a snowmobile trailer =)

hurco550 said:

I can tell your from the northern states when you haul bikes home on a snowmobile trailer =)

Click to expand...

shhhhhhhhhh nobody else noticed!

I replaced the spark plugs and installed K&N Air Filters (http://www.amazon.com/gp/product/B000E7H458?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00). I ordered a couple carb kits from a local shop that should arrive this Tues 11/3/15.
I attempted to check the points, but was unable to take the cover off. 2 of the 3 screws were stripped. I'm going to have to pick up a screw extractor to get those out. Does anyone have any tips for stripped screws?
I'm going to remove the carbs this week. I've got a Clymer manual, but if you have any tips let me know.

jdesignerw said:

I replaced the spark plugs and installed K&N Air Filters (http://www.amazon.com/gp/product/B000E7H458?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00). I ordered a couple carb kits from a local shop that should arrive this Tues 11/3/15.
I attempted to check the points, but was unable to take the cover off. 2 of the 3 screws were stripped. I'm going to have to pick up a screw extractor to get those out. Does anyone have any tips for stripped screws?
I'm going to remove the carbs this week. I've got a Clymer manual, but if you have any tips let me know.

Click to expand...

You'll need new jets. 2 of the Keihin secondary type main jet size 110! (EDITED from 105 which is the stock jet to 110 which is necessary for the K&N replacement filters)
Keihin secondary type main jet size 110 (SKU- 99202) From the JetsRus website.

Otherwise some of the site's sponsors sell them Dime City for example.
http://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-carburetor-parts-keihin-cv-secondary-jet-110-026-054.html

I would keep the original jets and clean them if they were mine. Since the "manufactured" kits nowadays are very hit-or-miss. Everything other than the mains that need to be larger that is!

Carbs are relatively easy to take out. Take off side covers, Unscrew one of the two 10mm cap nuts that run through both air filters (and double as side cover holders) then the long "stick" will come out. There's a single 10mm bolt holding the airboxes to the frame (top rear) and then the clamp to the carburetor needs to be loosened. The entire airbox comes out both sides. Note that there's a projection on the inside of each airbox that fits under the battery box in a little "tunnel" that's how they are connected and the rod goes through there for holding the side covers on.

Next up, I like to go to the left carb, loosen the choke lever umm..acuator bolt? You'll see how the little arm is attached to that side by a slotted bolt. Loosen that up and it should be able to slide off. It's a D key and you'll put it on the same way and then tighten the clamp down when reinstalling. Then you can loosen up the head side clamp and with another 10mm open wrench, loosen the throttle cables from each carb individually. I like to make sure the "locking" nut is in the same spot on both cables, as it makes synchronizing them far easier when you get her running. Then you'll have 2 separate carbs ready to be cleaned up!!

Lastly. Buy one of the $12 impact drivers. You will have a much better time with the old bolts on these machines. You can take off the adapter and use sockets if you wish, just make sure they are IMPACT sockets, because you don't want one of those exploding on you. I've never had any issues, but apparently bad things can happen if they aren't impact sockets. http://www.amazon.com/Powerbuilt-648002-2-Inch-Impact-Driver/dp/B004QO9FK2/ref=sr_1_9?ie=UTF8&qid=1446481324&sr=8-9&keywords=impact+driver+manual

Otherwise, find a drill bit that's about the size of the threads. Drill slowly until the head pops off. Take the cover off, and get a vice grip on the end of the bolt that is now sticking out. That usually works well for me.

Jet info from Herrdeacon in another thread: http://www.dotheton.com/forum/index.php?topic=18930.0

MotorbikeBruno, thanks for the all the advice. You are the man!

jdesignerw said:

MotorbikeBruno, thanks for the all the advice. You are the man!

Click to expand...

Not a problem. I just had ANOTHER friend drop of his CB350 today Double check that your floats are the same....haha...his were not.

Here are my new filters


Took the points cover off and found this... What am I looking at?

someone correct me if im wrong, but that looks to be an electronic ignition?

Correct! You've got some good ignition components!

http://www.cb450ignition.com/Index350.htm

I personally don't own a Pamco, but someone has spent a few bucks on the thing. Good for you sir! Hopefully it's already been set and you won't have to muck with anything. But if you do, check out the website. Or find the Pamco setup for yours. Good stuff sir!

While I was checking for the points I took the alternator cover off. There was a little oil in there. Is there supposed to be oil in there?

Also, a coworker recommended that I replace the inline fuel filters as a remedy for the loss of power at high rpms. I replaced the fuel filters and cleaned the fuel strainer in the petcock. I tried starting her and she started right up. The RPMs jumped to 4-5,000 before I cut her off. I adjusted the air/fuel mixture screws and after a little back and forth got her to idle with a little choke around 1200rpm. The amount of choke being used is very very minimal. I'm going to fiddle with it more after work. Does anyone know what the throttle screws should be set at for a 71 CB350?

Typically with the stock setup, you will be at .75 to 1 turn out on the MIXTURE screws. The THROTTLE stop screws are different. Without the proper vacuum gauge, these twins are all done by ear and feel.

So with the new air filters, I think you will be in the 1.5 turns out range if I'm not mistaken. Loss of RPM's is in the high range is due to insufficient fuel (you need 110's in there at least!) or poor timing some times. Yes there is oil in the generator cover, that's normal. Don't put the bike on the side stand with that cover off....you'll lose most of your oil!

I've always tried to bottom out a throttle stop screw the same way you would bottom out the mixture screw. Count how many turns it takes before it JUST stops touching the metal. Repeat for the other side and when you turn one screw to raise the idle, you turn the other the same # of turns and that helps keep them "in sync" as much as you can by ear. You'll also have to remember that your throttle cables may be in different lengths due to how you installed them with the lock nuts. So pull up on the throttle and see if they come up the same. Hope that helps.

Thanks that definitely helps. I was able to find the idle screw settings in my manual but it doesn't talk about the throttle stop screws. I'm still waiting to receive the carb kits in the mail so I've been tinkering in the meantime. I found out that the petcock was not flowing on one side so I drained the fuel tank and removed it. I cleaned it to be st of my ability and that seemed to fix the gas flow. I have a feeling that I'll need to replace it.

you have the cv carbs so the throttle stop screws are at the butterfly shaft
they are for adjusting idle speed only
to synch the carbs for throttle opening you adjust the cable housing at the carb
if it hasnt been messed with they might be fine in that respect
you have to pull the carbs to get them synced for throttle opening or cable pull as i call it
something like an 1/8" rod for each side as a gauge to the butterfly opening
you would adjust the housing at the throttle grip so that both slides lift until you can get some kind of gauge in there to synch them for cable pull
you only have to make sure with the carbs off the cables are relaxed and free like they are when under the tank
you put the gauge rod under the butterflies centerd carefull same both sides then back of the housing adjuster at the twidst grip until both rods are gently trapped by the betterflies.then slowly adjust so the start opening and you want the rods released at the same time compensate for variance with the cable for either carb where it ataches the housing adjuster
once done do not ever touch those cable housing asjusters when tuning only mess with them if you are prepared to do it all over or puttung on new cables

inline filters are not needed if the screen in the valve is intact and good shape
check it clean it
the 350 its not like a dodge hemi lol the inline filters will not effect perfomance unless the are clogged up
that is a pamco and a darn good thing to have the only thing you need to do with the pamco is check timing at full advance 3000rpm or so pluss you will see the advance working in the timing light image
this tells you somewhat if the advancer is working with the pamco you do not worry about the actual timing at idle being exactly on the marks
the advance is all that matters and you cant change both its impossible lots of people were trying to get the static/idle timing exactly on the marks as well as full advance this can only be so in a perfect situationm which is too rare
if it is on one set of marks but off the other you cant adjust it out it is simply impossible
what determines it is the condition of the advancer and the chance of it being exactly the same as new stock specs
that said the early pamco did have a serious issue i haver one i would know it is the engagement of the advancer pretty easy to check and look at if you grab that rotor and it is sloppy back and fortth engine rotation wise ,like in sloppy before you feel the spings then it has the problem. the fix i did was grafting together to pamco rotor to the stock advancer rotor to eliminate the issue which was aluminum in a high wear situation, well its not really high wear when it is hardened steel like stock

Removed my carbs and cleaned them.
This is a before image.


As I was reassembling the carbs the kit didn't have a secondary main jet. The float bowl gasket is also too big. I'm pretty sure I got the right kit. I bought it through the local bike shop.


I've read some bad reviews about the Keyster carb kits. It sounds like my complaints are common.
What can I do about the oversized gasket?
Can anyone recommend a carb kit?

I ended up cutting down the float bowl gaskets. That seemed to work fine with no leaks. After reattaching the throttle cables it wasn't idling right. Still trying to fiddle with idle to get that right. I was able to ride it a little when the weather warmed up for a couple days. Also, I put on side mirrors.

Yeah these are a bit of a pain to sync up. I find almost every 350 that comes in my shop is quite a bit off. I ended up using an old VW style airflow meter. It's fantastic on these!

http://www.ebay.com/itm/Carb-Sync-AirflowMeter-Dual-Carburetor-VW-Baja-Weber-Dune-Buggy-latest-rage-empi-/301149783258?hash=item461ded04da:g:2eUAAOxyUylTRtCr&vxp=mtr

jdesignerw said:

I ended up cutting down the float bowl gaskets. That seemed to work fine with no leaks. After reattaching the throttle cables it wasn't idling right. Still trying to fiddle with idle to get that right. I was able to ride it a little when the weather warmed up for a couple days. Also, I put on side mirrors.

Click to expand...

did you cable synch the butterflies ? as i described