Topic: I was wrong about my CB350F

[camelman]

I never thought my 350F would have enough power on the highway in stock form, but I just got done with a 4 hour ride in the hills of Marin, and never had an issue.  I had a friend on the back who is as tall as me, although she is a fair bit less than my 175lbs, but the 350F never missed a beat.  I had to downshift at low speeds on the uphills, but I held an indicated 80 in top gear on the long climb southbound on the 101 back into the City.
So, to all of those who keep asking whether or not a 350F is capable on the highway, I hope I just answered your questions.

To add to the beauty of it all, I got 50mpg on the tank after flogging it around in the city for half of the tank, then flogging it around in Marin with a passenger for the other half.  I love my bike.

Camelman

[Prospect]

How was the vibration at 80 mph?  You're reving pretty high by then I bet. 

[fmctm1sw]

I rode mine on a very short interstate jaunt one time when we went rafting.  I didn't care for the force of the wind and the cagers at that speed.  That must have been around 8000 RPM.   

[camelman]

At an indicated 80, the tach showed 7200.  I wear earplugs and a helmet, so the noise isn't an issue.  The carbs are definitely out of sync, but the vibrations were nothing to speak of at 7200 rpm.  It is just a great, smooth engine.  I am curious what my real rpm was, and what my real speed was.  I had originally assumed my speedo was way off, but I've realized now that it isn't too bad.  I think 80 indicated is really around 75.

The wind isn't bad with a passenger to lean against... it isn't all that bad without a passenger either.

Camelman

[Lars]

What is great with the CB 350 F, is that the real fun begins at 6000 RPM's and up. The bike is build for hight RPM and it is surpricingly strong. One of our clubmembers, a tall and heavier guy than me, took his bike for the real winding roads and up a hillside. He came home and imidiately sent us an email, telling us how positively surprised he was by the performance and power. As hs said; "I was smiling all the way inside my helmet".
Lars

[Terry in Australia]

The 350F is a great little bike, I restored one in 1996 and spent way too much money on it, but traded it for my 5000 buck lathe, and the guy I traded it with threw in 1000 bucks worth of tooling as well. Great deal! I am 6'4" tall and back then was around 220 pounds, and it'd do 90 MPH in top gear, but wasn't happy at those speeds, and was pretty gutless off the lights, I was often "dragged off" by crappy little Jap cars.

50 MPG isn't great though, my old Suzuki GS1000S gets 50 MPG, and so does my new fuel injected 2300CC Triumph Rocket III. Cheers, Terry.



 

[wdhewson]

Thanks for the encouragement guys.  I'm just putting together a CB350F right now.  But the first ride is many months away.

[mgbgt89]

I love my 350F. With all 130 pounds of me riding it, It's suprisingly quick. Made a 500 mile trip on it this summer. Passed a harley on an open stretch of highway. My speedo was indicating 90 and bouncing, his was showing 95. Top gear, very near the 10,000 rpm redline. At the rate i passed him, i had to have been going 100-105. Riding two up, the top speed is 75-80. Body position is everything. I can pick up 5-10 mph just by changing how i hold my arms when i'm laying across the tank with my feet on the back pegs.

It really needs a 6th gear.

[Nikkisixx]

The 350 Four is an awesome little bike.  I just started taking shake down runs of 15-20 mile local trips on my wife's 350f.  I had never ridden a 350f before, and this was not rideable when I got it.  It is smooth with a very wide power band, light and nimble.  My father in law had never ridden a motorcycle, and he tried it this weekend.  He took to it like a duck to water, and we had a hard time getting him off of it.  For backroads and in town cruising it is a perfect bike. It makes me smile every time I ride it.   

[supersports400]

Hi Camelman,

I have a CB400F and I rode 30.000 km on it, on European high ways. If possible I take the CB400F to Italy and Germany (work). In Germany I ride full throttle when applicable, and that at least 60 % of the trip length. A speed of 90 to 100 mph is possible over a longer time. Once above the 9500 rpm in fifth gear I go to the sixth gear and do a "steady" 8000 to 9000 rpm. At these speeds the mpg (or km / l) ratio is awfully, it does 12 km on a litre, that is 28.4 mpg (US gallon) But when sightseeing on the winding roads in the north of Italy is does 60 mpg or better (once in France I did almost 70 mpg). I have installed 78 main jets to give a little extra fuel at these speeds. Look at the power build-up at the dynoyet runs at the link below. The CB350 has the same power build-up, you have to let it scream to go (relative) fast. I don't know haw fast you can drive in the US, but I think the CB350f is fast enough o get a speeding ticket on the highway.

At the moment I'm in a rebuild (engine did 65000 miles), if interested see the link http://forums.sohc4.net/index.php?topic=65233.0

Jensen

1 mile = 1.60 km.
1(US) gallon = 3.78 litre.

[camelman]

Jensen,

I've been following your build, and am interested to see you finish it.  I have 80 mains in my carbs right now (per a recommendation from a local mechanic shop).  It is too much for the bike at the moment, but I'll be pulling the engine down for a rebuild and repaint shortly.  When I do that, I'll work on the head flow a bit, so I think the 80 mains will be correct at that point. 

I have not hit top speed on my bike yet, but I can assure you that even with two up it would do 85-90mph.  Heck, I think I hit that speed this weekend on a stretch, and I had throttle to spare.  Maybe those 80 main jets were the correct choice after all.

Camelman

[supersports400]

Hi camelman,

Thanks for following my thread, I just went trough a oil pomp rebuild in the thread, have fun.
You replayed once in the thread, tanks. I think it depends on the local conditions if 80 is too big or not.
As you can see in the second dynochard, 78 is good for a CB400F, but read the temp and pressure in the left corner.

Those fours where running lean in the 70's, especially in the higher rpm regions, so it's good to gif it a little more gas.

Jensen

[fmctm1sw]

It really needs a 6th gear.

There's a number of guys here putting 400F engines into them.  I'm trying to take it a step further in just putting a 350F top end on a 400F case...

[fmctm1sw]

At an indicated 80, the tach showed 7200.  
Camelman

I need to go look at my sprockets.  Something is up with both my bikes.  I always seem to be at a higher RPM than everyone else...

edit.  crap.  will have to wait for the weekend... forgot that big cover was on it

[camelman]

How do your rpm correlate to your speed in top gear?  My rpm is equal to roughly 90% of my speed, plus two zeros.

Camelman

[fmctm1sw]

At last, my sprocket report..

72:  15 front/38 rear
73:  16 front/38 rear

Without checking my book, I don't think either one of those are right.  I counted each of the rear ones twice and the front ones 4 or 5 times each.  That's what I got.  I didn't pay much mind when I put the bikes together, I was more worried about them running.  Smaller on front or bigger on the rear = slower right?
 
oddly, I have a 17 tooth front sprocket sitting on my shelf.

[fmctm1sw]

How do your rpm correlate to your speed in top gear?  My rpm is equal to roughly 90% of my speed, plus two zeros.

Camelman

When I went for a ride in the fall with some guys at work, I kept a steady 6000 RPM.  At a stop, the guys asked me why I was going so slow.  I said, "I'm doing 60."  They told me I was more like 47/48.  Pretty sure it was the '72 I was on.

[camelman]

So, I took the 350F out with a couple buddies this weekend.  One guy was on a new R6, but had only been riding motorcycles for three months, and the other guy was on a KTM super duke 990... and definitely knew how to ride.  I was floored by the amount of power the KTM had, and had a little trouble with the 1/4 turn throttle when I got a chance to ride it.  I don't think I like 1/4 turn throttles for street use.

Anyway, the point of the story is, the 350F held up very well.  I still have limp rear shock absorbers, overly stiff rear springs, and a front end that has not been rebuilt since at least 1976.  However, in the twisty bits, I held up with the KTM even when he had it slammed all the way over.  The R6 stayed behind as he wasn't comfortable enough with the corners.  The KTM only really pulled away after the apex when we were getting on the power, but even then I held with him until we were mostly upright.  I have to say it again, "I love my CB350F".

Oh yeah, the ride took longer than I was expecting, so I was about an hour and half late to pick up a girl to go to a barn dance (don't judge), ran out of gas before we had even left the city, then hit rain most of the way there.  She said she didn't care about the rain, so we went on.  The ride back was amazing up highway 1 with the stars out, no one on the road but us, and the moon reflecting off the ocean.  I might as well say it again, "I love my CB350F".  It just causes great things to happen.  ;-)

Camelman

[MickeyX]

It seems to me you need to keep the bike and the girl. She put up with you being late, running out of gas, getting rained on and then taken to a barn dance? Damn, she is a keeper, right there. 

[Deltarider]

You meet the nicest people on a Honda.