Topic: Thoughts on CB350F

[eithr]

I can't remember what info I shared previously, but looks like I am now the nervous owner of a 1972 Honda CB350F. The original intent was to hand this bike over to a friend for his birthday. That didn't go quite to plan, so I ended up buying the bike from him, so that he could just pick out a bike that needed less TLC.

If you've owned or dealt with one of these bikes, or witnessed some one else dealing with one, what has been your experience, suggestions, thoughts, etc? This winter, I'm planning to pull the whole thing apart and clean it up and get it ready for next riding season... if things go according to plan.

I'm seeing that parts for these things are a little rought to come by. I had a lead on a parts bike, but I think it's priced out of my range. Here are issues that I've diagnosed thus far:

1. Issue with compression (waiting to get the bike back from my friend - first project is a valve adjustment, which I hope will improve the compression).
2. Assuming wiring issues - blinkers and horn do not work properly, kill switch and push button starter have been disconnected.
3. Stock air filter system has been semi-removed. Needs lid to air box, new filter, and manifold reattached. Previous owner fitted pod filters, but didn't rejet carbs.
4. Previous owner swapped stock bars for clubman bars - the cable set up looks a little squirly, housings look questionable, nervous about the condition of the throttle, clutch, brake cables, probably gonna replace. Debating on keeping the clubmans or replacing with stock style bars.
5. Missing center stand, rear brake light switch, license plate holder.
6. Needs new tires.

Tank is in decent shape; small dent. Any tips for popping out a tank dent? Fenders look near mint. Exhaust in okay condition, some rust. It's a 4-into-2 set-up... debating on swapping to a 4-into-4 or a 4-into-1 set-up.

Was running when first acquired. Has since slipped into not-running condition. My friend replaced the spark plugs and battery... also replaced a coil (spark plug lead wire snapped off)... according to him it's still not running.

[flybox1]

First, dont be nervous. 
I had NO motorcycle skillz when i picked up my 350F.
I did have a strong desire to fix it and get it running.....AND i had the wonderful folks here. 

Now i ride it several times a week.

1.  probably will help
2. clean and pack all connections with dielectric grease.  change all fuses.  charge and test battery.
3. fab a lid for the airbox out of something.  get a new air filter.
4. CB400F bars are a nice fit and comfortable.
5. ok.
6. its not safe to ride with old tires.
Keep your 4 into 2.   
get your bike running WELL with this exhaust.  prime and paint it for now if you dont like the looks.  swap later if you want.

get a Clymer and a shop manual. 
do the 3000 mi tuneup
come here often and ask for help.

fire her up!

[eithr]

Oh and also, the petcock isn't original and appears to be garbage. I'm not very confident that I'll find a stock petcock, so any recommendations on petcocks that might fit the 350F? What are some options if I can't find a petcock that fits.

[flybox1]

try rebuilding it first.

but if non-op, you have a few options....

http://www.z1enterprises.com/SearchResult.aspx?All=True&KeyWords=petcock%20replacement

[phrige]

Hey!

First off congrats on your bike, even though it seems like it came to you in a real round about way.

Like Flybox said, dont Fret. When I got my 550 I was unsure where to get parts at a decent price, and thought of a parts bike. Wasn't worth it for me.

Through this board and others I've been able to find a TON of aftermarket dealers, small guys that will mail you parts, online retailers. its just specifying what you need to buy and searching the boards thoroughly. takes a little while but I've gotten some sweet deals on things like chains, sprockets, gauges, fuse box, so on..

Or theres always Honda OEM parts that you can get through any honda motorsports dealer. or Ebay, which is also pretty good.


so youre in good hands, If I'm not mistaken Soichiro Honda himself, the founder of the company, said the 350 four was his favorite bike, the pinnacle of his motorcycle technology.
Hows it feel to be the owner of technical perfection? 

Best of Luck with it!


Btw Flybox your response in the "rear an fast" thread just cracked me up, couldn't resist quoting you in my sig. 

[Trevor from Warragul]

No other petcocks will fit, not even Honda ones!  They do appear on e-Bay every so often, and sometimes you can score an NOS one at a reasonable price (as long as another desperate 350/4 owner isn't also wanting one)

Trevor

[eithr]

so youre in good hands, If I'm not mistaken Soichiro Honda himself, the founder of the company, said the 350 four was his favorite bike, the pinnacle of his motorcycle technology.
Hows it feel to be the owner of technical perfection? 

I didn't realize that. I was already pretty excited as I believe the CB350F is the smallest four cylinder bike ever mass produced. That alone is pretty wild. I'm pretty nervous about sourcing parts, like this hard to find petcock, but getting this thing back on the road is gonna feel super awesome. It looks like Z1 might have some options if I can't locate that petcock.

My buddy, who has the bike, but has rejected it's glory, is supposed to drop the bike off at my house this weekend or next week. I can't wait to tear into this thing.

What are some worst-case scenario causes and solutions to poor compression? If it ends up needing new rings and/or pistons, should I be able to do that on my own?

[flybox1]

Btw Flybox your response in the "rear an fast" thread just cracked me up, couldn't resist quoting you in my sig. 

 

[schwebel]

What part of Ohio are you in? I am in the Dayton area. I have a lot of CB350F extras. I know I have an extra center stand if you want it, it's yours. I also have a running engine. You will need to swap your stator in as my 400f one took a dump and I stole the 350f one. I ran it for around 1000 miles with no issues. It shifts and purrs like a sewing machine. The only reason I removed it was to put a 400f engine in my 350f. It's yours for $75. I run the "superbike" style bars which are similar to 400f bars, I really like them. They are comfortable and give you great control.

[betterthanurs916]

 I believe the CB350F is the smallest four cylinder bike ever mass produced.

Not trying to be rude...but thought I would throw out that there were smaller in-line 4 motorcycle engines that were 'mass' produced...

The Moto Guzzi / Benelli 254 comes to mind.

http://www.bikez.com/motorcycles/moto_guzzi_254_1977.php



But...yeah...I don't know how many of them actually made it to market...whereas the 350f was moderately popular...I think that statement is still pretty fair...looks like the Italian bike might be based off of a Honda design anyhow.

[schwebel]

As far as installing new rings and/or pistons, it's not that hard of job. But you need to check your bores to make sure they are not beyond honing. The 350f has a reputation of wearing out bores. If they are past honing, you will need new oversize pistons and rings. If they are within spec you will only need new rings and a hone. Bore-tech near Cinci did a bore job for my buddies 450, and I would recomend them. I would check the head before worrying about if it a bad ring. You might just have a worn valve stem seal and/or guide, a much easier job.

The hardest part is getting the cam in right with either job. It really takes two people IMHO.

[HondanutRider]

 I believe the CB350F is the smallest four cylinder bike ever mass produced.

Not trying to be rude...but thought I would throw out that there were smaller in-line 4 motorcycle engines that were 'mass' produced...

The Moto Guzzi / Benelli 254 comes to mind.

http://www.bikez.com/motorcycles/moto_guzzi_254_1977.php



But...yeah...I don't know how many of them actually made it to market...whereas the 350f was moderately popular...I think that statement is still pretty fair...looks like the Italian bike might be based off of a Honda design anyhow.

Yes, there are many examples of smaller 4-cylinder motorcycles - they just weren't marketed world-wide as the 350 Four was.  In the Japanese market, all the big four manufactures recently had some really hot 250 Fours.  Here's a link to one of Honda's model: http://www.dropbears.com/r/roadtests/cbr250rr.htm  The history on these small fours is interesting, as back in the 1990's they were getting just too fast for their size and officials mandated restrictions on them to curtail their top speeds.

[scottly]

I knew a guy with a 350-4 in the late '70s. It was a great little bike! I would love to have one to play with.

[Stev-o]

Jump on that motor for $75!

[lowflyingdutchman]

Close your eyes.

Take a deep breath and empty your mind.

Allow The silence to slowly take over your being.

Months of grease.

Silence.

Dirty old parts being returned to perfection.

Return to your core.

A Howling whine as that gorgeous little motor jumps back to life.

Release your thoughts.

An idiot friend who spends the next 20 years regretting the purchase of his plastic crotchrocket while you harvest the glory with a true classic.

Fill your body with a warm light eminating from your forehead

Your own thing. Your own beat. Your own colors. Your own speed. You now own a Honda. Loved by few. Hated by many.

Come back to reality by following the sound of my voice.

Welcome Aboard. Were about to take off....

[fletcha221]

Hey! Congrats! I bought me cb350f for 150 bucks on craigslist.....I'm pretty sure you are better off than I was. I'll throw out my own 2 cents for your questions. Check out my blog, I detailed the whole build.


http://cb350fcafe.blogspot.com/


ANyway, on to the questions:

1. Issue with compression (waiting to get the bike back from my friend - first project is a valve adjustment, which I hope will improve the compression).

- How bad? How far offf are the readings from stock? A few PSI isn't always worth tearing the thing apart, im my opinnion.
2. Assuming wiring issues - blinkers and horn do not work properly, kill switch and push button starter have been disconnected.

Clean all the deutch connectors and all connections.
3. Stock air filter system has been semi-removed. Needs lid to air box, new filter, and manifold reattached. Previous owner fitted pod filters, but didn't rejet carbs.

#85 jets and 4 cheapo pods. I ran a 4-2 exhaust....it ran perfectly.

4. Previous owner swapped stock bars for clubman bars - the cable set up looks a little squirly, housings look questionable, nervous about the condition of the throttle, clutch, brake cables, probably gonna replace. Debating on keeping the clubmans or replacing with stock style bars.

if you arent completely sold on clubmans, do to a drag or OEM bar....the clubmans are ....a little uncomfortable if you are over 5-9 on that bike.
5. Missing center stand, rear brake light switch, license plate holder.

I scraped my center stand.....really wish I didn't. The look was strictly cafe...but having that center stand is nice.  As far as the switch...I bought my new one on ebay fro 17 bucks. Do a side mount licence bracket/tail light.....I think it looks nice.


6. Needs new tires.

-Coker tire, check them out!!!

[eithr]

Thanks for all the great advice and positive thoughts, everyone. I'm getting more excited about this project. If all goes well, my friend (who rejected the Honda) should be delivering it back to me this weekend.

I'll have some help, once the project begins. I don't have a garage, so we're planning to work on the bike at my friend Dave's house. He's an experienced car mechanic and bike enthusiast. We're both excited to get more experience working on bikes, and we're way excited to be breathing new life into this old bike.

I'll keep you posted. And, photos to come!

[Bodi]

Compression readings are difficult on a CB350. To compare with the specification numbers you need to use the same compression tester as Honda used and we don't know what that is. The cylinder volume is very small so the added volume of the compression tester up to its check valve reduces the possible compression reading. Look for consistency more than  actual value. If your compression gauge has the check valve in the spark plug adapter the readings will be pretty accurate, if the check valve is further down the hose you will get low readings.
The wiring is usually an issue with these old bikes, POs just love to butcher the wiring harness.
Use a real Honda wiring diagram for you exact model and year. You may be able to find one on the web or you can order a service manual, there's a company that prints them on demand. No Clymer or Haynes or colored generic wiring diagram on the web is useful, they are all simplified and inaccurate: to fix a butchered harness you need the complete diagram that's in the service manual or the original owner's booklet.
The rear brake light switch is pretty generic, you can get one that's meant for almost any bike or snowmobile. It just connects to the brake lever with a little spring.
getting airbox parts may be difficult but there are probably people here with what you need. Post on the "parts wanted" board.

[pilotguy1050]

Soooo..... what happened??     I'm really enjoying these posts! 

[eithr]

Sorry for the black-out. Some other stuff got in the way and I have made about zero progress on the 350. I picked up a 1971 CB450 Twin about a month ago and have been concentrating on that. I'm painfully realizing my lack of mechanical experience, but I'm making some slow progress.

I finally got the title corrected, for the 350. There was an issue with the VIN. To my surprise, it was a very painless experience getting that corrected.

I just made a connection with someone in the sculpture lab, here at the college I work at, so I plan to media blast the frame and swing arm in the next couple of weeks. Debating on color schemes... kinda thinking red or black for the frame and then polishing the tank and just clear coating it.

Work calls... to be continued.

[eithr]

Continued...

I still need to figure out the specs for rejetting the carbs to handle the pod air filters and 4-into-2 exhaust system. Anyone have recommendations on jet sizes?

[eithr]

Also - what are some solutions if I can't find a stock petcock? Why are these things so difficult to locate? Also, I have the stock air filter system, just not the lid. Any help with these bits would be much appreciated.

[fmctm1sw]

Are you going with pods or the stock airbox?  I'd recommend a stock airbox at this point so you don't introduce more issues into an already non running bike.  Keep an eye on Ebay for an airbox.  You may have to buy a while airbox just to get a lid, I did.  You should be able to find a petcock on eBay too.  I have about 10000 miles total between my two 350Fs, trust me, it will serve you well...