71 CB350 Project (Sold!)


New Member
Gentlemen and Ladies,

I recently purchased a 71 CB350 in decent condition. I am trying to get this bad boy up and running great first, then I will do the modifying. Also, I am trying to be as cheap as possible.

Today is the first day I have been able to get my hands dirty. Thankfully the previous owner had already removed the stock airboxes and blinkers for me, as well as cleaned the carbs

I went straight to work.

Gas tank off, disassembled the petcock. (There was a little rusty looking stuff inside). I will thoroughly clean before I put it back on.

Removed the carbs, they were clean, but there is a small tear in each diaphragm. :'(

I removed the rectifier, the previous owner said he thought it was bad. Either way I am replacing it with the ingenius Radio Shack one for $3.50. http://www.dotheton.com/forum/index.php?topic=6496.50 Thank you $50 mod blog

Some questions so far.

Should I just say "screw it" and replace the carbs with Mikuni ones? If so, which ones?

What do I clean the petcock with? Carb cleaner? Minus the rubber O-ring of course.

Any recommendations on cleaning and sealing the gas tank?

Pics are below, and I am sure more questions will arise. Thanks all

Welp, back to work



New Member
Re: 71 CB350 Project

Nice bike. I have exactly the same one, down to the color.
How many miles?
What is the compression?

Two things you should check first before anything else - these will give you a good idea of how much money you will need to put into the engine. If you get >150 psi for each cylinder, don't do anything to the engine unless you notice any other sever problems.

The carbs can be repaired, depending on how big the hole in the diaphragm is. I used a very small dot of epoxy on mine and its been fine so far. If you have the money, and plan on modifying the intake and exhaust, mikuni's are very easy to tune, as you don't have to remove them to change the jets (this IS worth the extra money in my opinion). VM 30's seem to work well. petcock can be done with carb cleaner, remove gasket as you said.

I had my tank done for $150. I know its a lot, but it was a present from my father, and it was nice to not have to deal with it, especially as I didn't want to mess up the paint.


New Member
Re: 71 CB350 Project

Thanks Richa for the advice.

17515 miles, and compression is right at 150. So thats good.

I will look into the VM 30's as I will eventually modify the intakes and exhaust.

Also my tank is pretty heavily faded, and will require some painting. Bummer

Time to get to work on that petcock.

Removed pipes, headers, rear footpegs, and chain guard.

What is a good cleaner for general cleaning. Any degreaser?


New Member
Re: 71 CB350 Project

A squirt bottle full of kitchen degreaser and a hose. Spray down, let sit, rinse, repeat. A lot. If you're in a place that you can do it now outside...
I took mine in a trailer to a do it yourself car wash and pressure washed the crap out of it. I didn't make it spotless, but it did make it much less messy when I did take it apart.
If you hate your lungs and the environment, brake cleaner will dissolve pretty much anything, but its pretty nasty stuff. Otherwise, a general engine degreaser spray can can be had pretty cheaply from your local auto parts store.


New Member
Re: 71 CB350 Project

Been doing a lot of general cleaning on the bike the last few days. Degreasing everything, cleaning chrome, etc.

Things I did besides cleaning:
Drain the old oil.
Remove the electric starter and plug the hole fairly easily. Plugged it with a frost/freeze expanding plug from Autozone for $4.00
Remove old battery box and a bunch of other junk that wont be used anymore.
Made the $4 Solid State Radio Shack rectifier, and removed the old one. http://www.dotheton.com/forum/index.php?topic=6496.50

Today, I am going to order parts. Most importantly the carbs Mikuni VM30's. These are the correct one right?http://www.powersportsuperstore.com/ProductDetails.asp?ProductCode=4459629&Click=35355& FREE Shipping and not to bad of a price.

Any pros or cons to these? I have heard they are pretty good. I also planning on adding pod filters and different exhaust at some point, and I heard these are easier tuning.

Also I am going to need new tires and a new chain. Any suggestions or brands I should avoid.

I am also thinking about redoing the wiring harness completely. Is this something I should do. I no longer have turn signals or the electric start. Does anyone have diagram for this?
Thanks for all your help gentlemen.


New Member
Re: 71 CB350 Project

man i call dibs on the signals and side covers if you are getting rid of them. and if you want to get rid of your control switches (left side specificly) let me know. have a 71 cb350 that the PO removed the turn signal stuff and my side covers have missing vent pieces.

my 71 cb350 would be very happy to have some of that stuff :)


New Member
Re: 71 CB350 Project

Hey Moe,
Good news, I am getting rid if the signals, switch, and side cover. I will clean them up for you. The PO did however remove the emblems on the side covers. I will post pics of all the stuff I am getting rid of sometime today.
Thanks for the interest.


New Member
Re: 71 CB350 Project

man you are too good. i have got really good condition emblems so thats no problem. ya if you want to let the whole switch assembly, all four signals, and those side covers go i'll take them.

pm me to let me know what you are looking to get out of them


Active Member
Re: 71 CB350 Project

Good start so far man. If youre getting Mikunis (recomended) get them from Dime City Cycles. Theyre members here and awesome guys.
Theres a stripped down wiring diagram on the site somewhere. If you cant find it let me know, and Ill se what I can do.
Also... Take those fork covers off and inspect the crome tubes. If theyre nicked or rusty in the travel area youll need new ones. I can almost gurantee that youll need new fork seals as well.
Replacing the wheel bearings is a pretty good idea too, as theyre cheap and its a bit of added security.


New Member
Re: 71 CB350 Project

Hey all,
Sorry its been a while. Made some progress on the bike though.

Got the electrical all sorted out. Reran the wiring harness and removed the unnecessary wires.
Got a new battery - 12v 3.3AH from Batteries Plus - $27
Hid all electrical and battery under the seat
Made a bracket for it all using angle aluminum and lexan
Started work on a two person seat using a skateboard, it turning out nicely
Pulled off and cleaned the front suspension, have to put new fork oil in still.
Removed the rear springs and painted
Cleaned the tank out with "The Works", thank you $50 Mod thread
Painted tank and headlight assembly as well as a few other little things
Removed and cleaned up both sprockets.

Still waiting for my carbs to arrive, then I can actually get this sucker up and running

Thanks all for your help. Its greatly appreciated


New Member
Re: 71 CB350 Project

Some pictures of the gas tank. Still needs a good strong clear coat.

Anyone have any recommendations for a very strong clear coat?

Also, I need a new front tire. 18-3.00 Any specific tires I should look into.
Need a new chain

I dont want to spend a lot

Thanks all.


New Member
Re: 71 CB350 Project

Hey all,

I got my carbs in finally. Mikuni Vm30's. I know I need to make some intake adapters. I there any good place to how to hook these all up.

I am assuming I need a 2-1 throttle cable is this right. Any other info would be great.



New Member
Re: 71 CB350 Project

Thanks, I got it all mounted up last night. So far it looks like its going to work out pretty sweet. I really like how the back fins up.

I am planning on putting my tail light right underneath the fin. Just have to find a small bright LED taillight for cheap.


"Against All Odds".
Re: 71 CB350 Project

Wait you can put a small battery like that on there? how can that be?

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