Topic: 73' CB350F Easy Upgrade Recommendations

[buzzi785]

Hey there,

Just looking for advice on some reliable upgrades for my CB.

-I've considered installing some Mikuni racing carbs but those a like $500 I think...
-A buddy of mine mentioned changing the sprocket wheel so that the bike has more pull.
-Installing an Electronic Point Unit.

Any other recommendations are greatly appreciates.

Thanks!


Sent from my iPhone using Tapatalk

[calj737]

Drop a 400 motor in it.

Skip the notion of simple bolt-ons making a substantial difference. Mikuni race carbs on a stock 350 would be (pardon the candor) absurd. Electronic ignition isn't going to "boost" power. Sprocket changes can effect how a bike accelerates and how it cruises, but its not really going to produce any changes in HP.

If you can find a donor 400 motor, do a rebuild on it with a 466 kit, some decent head work, and away you go. OR, simply plump down a few thousand on a brand spanking new CB500 and be done with it. 

[Scott S]

 But dropping a 400 in isn't just that simple. Sure, it bolts right up, but the pegs and shifter aren't quite a match. And you'll have interference  with the 400 exhaust if you use the stock header.

 Just tune up the 350 to get it to run the best it can. They're fun, desirable bikes. If it's not enough for you, you can probably sell it and get enough to buy a 500/550. More power right off the bat and respond better to upgrades.

[Bodi]

Another rainstorm for this parade. The 350 is not a good candidate for hop-ups.
A 340 Four is smooth running and pleasant to ride around on. The 350 twin has quite a bit more power and is lighter...
The bike is probably worth more stock than after "improvements". Whatever you spend on performance mods will most likely only lower the value, this is a rule for pretty much any Japanese bike.
For personal joy (ignoring resale value) it's a fairly easy engine to work on and you can get a bit more oomph out of it. Not much though!
You can put a 400F engine cylinder/head on the 350 main cases, I think the sleeve holes have to be hogged out a bit. Even hop that 400 up to 466 if your budget is elastic. Then there's porting, bored out or bigger carbs, free-er flowing exhausts... Kaching!!
A smaller front and/or bigger rear sprocket will give more acceleration but with higher rpm at speed. The engine makes power (what it does make) at high rpm, but it can't come close to redline in top gear with factory gearing. With only 5 gears you can't really spare one for "cruising" if you want a hotrod feel. Extreme final drive ratio changes make the stock gear ratios difficult, they are picked to give good shifts as-built.

[flybox1]

-Avon AM26s
-Shorter bars, like Euro or 400F bars.
-Refreshed suspension (adequate rear springs for your weight, and new progressive springs in unpitted fork tubes)
-SS brake lines.  Drilled/lightened rotor.  Phenolic caliper piston.  New brake pads.
Points w/ a Hondaman Ignition unit.

Done.

[carnivorous chicken]

-Avon AM26s
-Shorter bars, like Euro or 400F bars.
-Refreshed suspension (adequate rear springs for your weight, and new progressive springs in unpitted fork tubes)
-SS brake lines.  Drilled/lightened rotor.  Phenolic caliper piston.  New brake pads.
Points w/ a Hondaman Ignition unit.

Done.

This is good advice, although I run plain points in my 350Fs and they're just fine. I also keep them pretty stock, including front brake, but I'm not trying to break any records. Good tires is a good plan. I would also add: you've got exhaust options. Most of the 350F bikes I see for sale have crappy 4-2 exhaust systems. I love the stock 4-4, but they are super rare and expensive (I passed on a really nice set about 17 years ago for $150 and have kicked myself ever since). Mac 4-1 seems to be the go-to option, but they're cheap and crappy. Stock 400F pipes work and aren't that pricey these days, but you'll need to switch out the pegs (400F, and people re on to this mod now so they're kinda pricey) and the kickstarter (550F for it to clear the pegs). I've got a 400F engine in a 350F frame, and while it's true there are some mods involved (brake lever mount, e.g.) it's not that tough. But I'd echo what others have said -- keep it mostly/close to stock, get it running well, and have a blast. These are one of my favorite bikes.

[buzzi785]

Drop a 400 motor in it.

Skip the notion of simple bolt-ons making a substantial difference. Mikuni race carbs on a stock 350 would be (pardon the candor) absurd. Electronic ignition isn't going to "boost" power. Sprocket changes can effect how a bike accelerates and how it cruises, but its not really going to produce any changes in HP.

If you can find a donor 400 motor, do a rebuild on it with a 466 kit, some decent head work, and away you go. OR, simply plump down a few thousand on a brand spanking new CB500 and be done with it. 

Thanks!


Sent from my iPhone using Tapatalk

[buzzi785]

But dropping a 400 in isn't just that simple. Sure, it bolts right up, but the pegs and shifter aren't quite a match. And you'll have interference  with the 400 exhaust if you use the stock header.

 Just tune up the 350 to get it to run the best it can. They're fun, desirable bikes. If it's not enough for you, you can probably sell it and get enough to buy a 500/550. More power right off the bat and respond better to upgrades.

Definitely something to think about.

I attached photos of my CB if you want take a look.


Sent from my iPhone using Tapatalk

[buzzi785]

-Avon AM26s
-Shorter bars, like Euro or 400F bars.
-Refreshed suspension (adequate rear springs for your weight, and new progressive springs in unpitted fork tubes)
-SS brake lines.  Drilled/lightened rotor.  Phenolic caliper piston.  New brake pads.
Points w/ a Hondaman Ignition unit.

Done.

This all sounds good to me. Thanks!



Sent from my iPhone using Tapatalk

[BomberMann650]

A distinguished 400f owner was jealous of my 550.  Citing that even at 7000rpm the gerbils in the 400's motor just arent that energetic.

[Duanob]

If you're looking for power and performance, sell it and get a newer bike. Other wise love it for what it is, an old vintage ride.