CB350 wanting as much power as my wallet can afford.

I have a 1972 CB350.

When I got the bike the motor was locked up. I have already torn down the entire bike/motor. My main goal is to go 100 MPH safely. with that being said...

My cam is shot. should I go back with a stock cam or a performance/aftermarket?

I have two stock carbs with the diaphragms in decent shape (No tares as far as i can tell) , but the slides are stuck....should i spend the money and go with mikuni carbs?

I also want to bore it out the full mm/ .004.

What type/brand pistons should i get? (is it worth paying $150 a piston for weisco) do you know of any comparable pistons?

I would also like to port/polish the head as too.

I would also like to eliminate the electric starter as well.

I plan on polishing everything I can. Should I sand/media blast the engine casing and cylinders along with everything else?

I am a beginner at best. I want to build the best that my wallet will allow. I am willing to do as much of the work as my skill/toolbox will permit.

Any help will be greatly appreciated

THANK YOU!!!!

If you want real power your wallet better be large.

A megacycle cam, overbore, and Mikunis in addition to a proper exhaust is a great start but you're already near $1000 in including machine work.

Start going further down the rabbit hole than that and you'll either build a grenade waiting to go off or if done right, a full race motor that will suck to ride on the street. The 350 is a commuter bike and the engine design reflects that. Fact is that if you want real go fast for reasonable cash, you boight the wrong scoot.

Build it up to run strong and cut all the weight you can from the rolling stock and chassis. Enjoy it for what it is. I fun and reliable little bike. If you MUST have speed and power beyond the 350s capabilities than yoi need to move onto a different machine. Maybe something from the RD line or the Honda 500four or 400/4 are good bikes of similar size. That said you're still dealing with a 35+ year old bike built with 50+ year old tech. Real power costs big money. How fast can you afford to go?

Oh, and welcome to DTT.

Thank you for your quick response.

Im not a speed demon, I would just like to do the ton, but if its going to break the bank I can always do it on my next bike.

with that being said is there any tricks/parts I could do to make it faster than my buddys stock 350?

reliability/ride ability is my #1 priority.

Cut weight.


New tires, shocks, bushings, bearings for safety


Power is expensive on a 350. I think the 1k Von quoted is even pretty I realistically low just for parts. Shop time is very expensive as well.

Don't remove the starter unless you are going to remove battery and go with pvl. Weight savings are not worth the inconvenience.

Find a "type 1" top end from K0 model. Ditch the restrictive and heavy stock exhaust. Mikuni VM28 carbs. Port and polish the top end. Big bore pistons... There's plenty. If keeping the price low is important, focus on weight loss amd handling first. Upgrade the suspension and get rid of anything that doesn't make her go and STOP. Remember that these aren't drag bikes. The way to really win is in the corners. Drag racing is for Camaros and Busas. Make it handle and its already "faster".

100mph safely, where ? :

fair enough.

how big on the bore size? any piston preference?

I like the idea of having electric start. my buddy has a 1970 and had charging problems. thats why i thought taking the starter off would help.

for exhaust i was thinking i would run straight headers, but i know thats not the best way to go about it.

what part of the suspension shoul be upgraded?

sorry if i am running off at the mouth i am just trying to take in as much as possible.

I recommend just covering the basic upgrades first...Add Intake, exhaust, and Carbs upgrade if you want. Next have the suspension done. Then upgrade the brakes, and wheels if you want. Throw some good rubber on it. With these simple upgrades you'll have a modernized Cafe that can handle the power you want to throw at it.
Now you can start doin the performance upgrades: Cams are cool but require upgraded springs and head work $$$$. Pistons stay close to stk compression but I'd go with JE pistons not Weisco. Big bore kits aren't worth the effort or hassle. Contact WebCam and see what they can do with your Cam. Throw a new crank and bearings in...
The main thing is make sure it runs and stops. Suspension makes it handle and stop better. Have it prof painted. Then post a pic so we can gawk at your work.

Good Luck...

I definitely want to STOP should i rebuild drums or go with disk brakes in the front?

Boxofparts72 said:

I definitely want to STOP should i rebuild drums or go with disk brakes in the front?

Click to expand...

There are some fairly easy disk upgrades but the drums aren't terrible on the 350s. New shoes and polishing and cleaning the internals helps.

New rear shocks and progressive front shocks with new seals is a good upgrade. For rear shocks halons are good for the money. You can get cheap Chinese shocks on eBay but they need to be rebuilt to be worth anything.

For a beginner I recommend buying a manual and going thru every system on the bike.
Then once your familiar with the machine, decide what you need to change.


.

All of this information helps a lot

I planned on getting the tank painted by a professional. I was wanting to do stock graphics on the tank just a different scheme. Thats the only part I planned on having done professionally. I would like to polish the parts I can and rattle can what i can't polish.

i don't have a parts washer so i have been scrubbing everything with grease lightning/CLR and its coming pretty clean but i would like to clean it, sand it, and start to polish. any tips?

i meant stock graphics just different colors

That ^^^

Do your research!!! Get it running and riding tip top first. Then dive in. In reality, it's tough for any of us to really point you in the right direction as we don't know what sort of experience you have with modifying motorbikes and more importantly... Your experience with RIDING. So...

Let's get that all out for everyone to see and go from there.

And if you have the motor I pieces, erase the word "paint" from your vocabulary until it's back together. The now disassembled engine should be job one.

Thank yall for all your help! I hope my ignorance will not stop you all for replying to my threads and turning these parts into a motorcycle.

The best thing you can do, as an inexperienced wrencher/bike builder, is keep the project as unambitious as possible. That way, you are much more likely to succeed. If you get too ambitious, the bike will never be finished, as you are already in way over your head.

KISS

Don't over-reach. Keep it simple and cheap. Get the bike running. This is your learning experience, and there is plenty to be learned without going overboard.

And read this:
http://www.dotheton.com/forum/index.php?topic=55066.0

Basically what these guys said 8)

If it were mine I'd go in this order:

Clean it up and get it running right.
Then cut weight. Ditch everything you don't need and replace with lighter stuff.
Then tires and brake overhaul, bearings if you need them.
Taper roller bearings for the steering stem.
Maybe some handlebars so you feel better about the look.
Upgrade rear shocks (stick with close to stock length)
Then I would probably add the Mikunis and some K&N filters and fiddle with the jetting.
From there redo the exhaust, do NOT run open headers you will lose power which is the opposite of your goal. I'd personally find or make a nice 2 into 1 with a reverse megaphone.

At this point you'll have a nice bike thats faster than your buddies and handles better too.

From here you can do some engine upgrades if you want, cam, pistons, port, polish $$$$
And then start messing with the cosmetics to make it look faster than your buddy while its standing still 8)

And the post important thing:
Do each of these projects individually. I can't stress enough how much harder all this is if you tear the thing to pieces before you do anything and try to do 40 projects at once. Do one thing at a time and you'll always have an end in sight and you will always be able to feel/see the improvement piece by piece.

Zero point in tossing money a performance parts if you haven't mastered the basics of keeping it going stock.
On another front it doesn't make sense to blindly modify a system you have not lived with to find a base line.

Slowly improve each system. Thinking about how it effects the bike as a whole.
Most of the power and speed stuff is a waste on the street. You go from a lot slower then a mom in a minivan to slightly slower. And you will only really tell the improvement if racing a stock bike.

Focus on stuff you can feel.
Brakes
Good suspension, like actual parts, not eBay remote res shocks
Alloy wheels and good tires
Bottle neck on the Hondas is the head. So have the head done.
Then maybe carbs
And if you really get to the point of more money then sense pistons

Removing the kick starter is dumb.
No real savings and a real pain when trying to dial in a bunch of random parts.