Cafe Racer Forum banner

cb350 twin rebuild

3K views 22 replies 8 participants last post by  Slumlord 
#1 ·
Hey I am wondering if it is a good idea to bore out my 350. It has 17k on it and looks great inside. I am not too sure what these motors can handle. I would need to know what I need to do to the top end as well as the bottom end. Or if anyone out there has a set of pistons for this bike I need some. e-mail me at ppiboy21@yahoo.com or post it here. Thanks. I will take all of the information that I can get.
 
#2 ·
these bikes can handle more than you are likely to want to spend getting it there, but before anyone starts in on that how about you post some photo's, history, give us an idea of what you know and what your plans are for this bike.

if you are going to bore it as a performance enhancement this is the site you want.
http://home.earthlink.net/~toddhenningracing/index.html


get the shop manual here
ftp://manuals.homeftp.net/Manuals/Honda/Honda CB,CL,SL 250-350

and when you post the picts you have to use lower case ('s) or it won't post.

...connoisseur of slack...
 
#3 ·
i have a basic knowledge of motors and rebuilding them. I have rebuild two civic motors and currently drive one of the cars daily. But that is a car. I have never rebuild a motorcycle motor. not too much different other than size. I was just unsure of the tolerance these motors could handle. Also given the age of the bike and the mileage I am unsure of what to expect. I have a manual on its way already, and have torn down the motor. I am going to start cleaning off all of the dirt and crap from the engine and frame. I am just looking to gather all of the information that I can about this bike and where I can go with it.
 
#5 ·
i kinda think it depends on what you want to do with it. if youre going to ride it, bore it with the biggest pistons you can get from honda. dont bother just going .025 over. (go 1mm over) you can still get em from honda, or watch ebay. i buy all my pistons on ebay. rings too. waay cheaper than honda. pistons will run you 60 each and rings will run you about 20 each from the dealer. you can buy the whole kit for about or less than 100 bucks on ebay. the cyls are easy to get, so dont worry about going too big. jugs are a dime a dozen. a standard valve job should do wonders. get a radiused type if you can find someone to do it. new springs, help usually. but you can check them to be sure they are in spec. (the book will cover it). if youre going to race...depends on what class and which club. you can go crazy and spend thousands on a race motor easily. the bottom ends hardly ever fail. get a slipper type chain tensioner.

jc
 
#7 ·
art is what youd get from honda. most pistons come with pins and clips. from honda, you have to order the rings seperately as you can just put in rings. so they are seperate. if you buy a kit form tucker of someother place, they will most likely come with the extra bits. id buy a hap jones setup if i could.

jc
 
#8 ·
I am not looking to race the bike, however I am looking to make a radical custom out of it. I do want it to run strong and sound mean. i started cleaning it tonite and the motor looks great. I can't wait to start ordering parts for it. Oh by the way I have no idea how to post a picture on here.
 
#10 ·
just throw stock pistons in it. itll be reliable, and you wont have to replace them every year. go 1mm over, with some oem pistons. (arts) you can run mikunis on it if you want it to run a little better. also a 1mm bigger intake valve. then some megs...youll sound plenty mean. you could even run a mild cam or look for the early fat cam and followers. thatd be about as cool trick as you can get while still staying pretty stock and reliable. the bigger you build them the more difficult it can be to build and less friendly for the street, and for someone who doesnt know what they are doing.

work mostly on shaving weight, and excess junk. they can look real cool with alot of crap moved or removed.

jc
 
#17 ·
I am thinking of switching from drum brakes to disc. any idea of where to get a good kit. Is this a good idea or will the drums hold up. I am only familiar with disc style brakes. This bike is the oldest machine I own and the other ones have disc brakes. Should I convert and where do I go. Thnaks
 
#16 ·
I am thinking of switching from drum brakes to disc. any idea of where to get a good kit. Is this a good idea or will the drums hold up. I am only familiar with disc style brakes. This bike is the oldest machine I own and the other ones have disc brakes. Should I convert and where do I go. Thnaks
 
#22 ·
unless you want to die you should leave the front break. i believe the number from the motofun course is something like 75% of your breaking should be on the front wheel and these bikes are plenty fast to require them both. if you want better breaking for the front get the shoes resurfaced with modern material.

what year is your bike? and what's wrong with the carbs you have right now to warrant a new set?





...connoisseur of slack...
 
#23 ·
I'm with Snorkelfork, you are asking for trouble by removing your front brake.
Have you taken the Basic Riders Training Rider's Course before? If not, I highly recommend it. It should be available in your state and usually, when you take it, you are essentially certified to go to your DMV to instantly get your endorsement.
The point I'm trying to make is that the class is so super informative and talks a lot about different points on your bike that you may have questions about. Brakes, for instance, front brakes take the brunt of the force, I think 75%, like Snorkel said above. Removing them would be like playing Russian Roulette. Also, about your drum brakes, as long as your shoes are made with modern materials and adjusted properly, they will be just fine. They aren't as good in the rain, but who wants to ride in the rain anyway? From what I heard, you'll spend more than the bike is worth in time and money by trying to convert to disc brakes.

Just my 2 cents.

Good luck!!

PS: Have you purchased a Clymer or Chilton's yet for your bike? If not, get one, they help a lot!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top