Topic: cb350f running issues + pics (new video on page 5)

[HondanutRider]

Does anyone know what that buildup is from?  All of the carbs I have pulled apart have the same general color of dirt caked inside them.  I just figured it was soil that got into the old cast iron fuel tanks at gas stations (very prone to cracking, hence the nationwide fuel station tank replacements a few years ago), but I can't imagine every fuel station would have the same colored dirt.

Camelman

I would expect that a lot of that "buildup" is rust crud.  The inside of tanks can get very rusty after they are cleaned by etching the rust out.  (Don't ask me, Flash, how I know. )  The only way I believe to prevent this from happening is to line the tank interior with a good sealant that will prevent future rusting, which is what I have just done to my CB360F tank with the POR-15 product.

[fletcha221]

Davis,

Sorry man! I was away this weekend, sorry I couldn't help you sooner! Well, It looks like you found your problem?  By the time the spring time rolls around, you are going to have this thing dialed in! Well, Keep up the good work man!

Natty light bottles? Man, when I was in college we could only afford the cans. But.....I was riding a brand new 04' GSXR600.....so thats most likely why.

[davis96]

Davis,

Sorry man! I was away this weekend, sorry I couldn't help you sooner! Well, It looks like you found your problem?   By the time the spring time rolls around, you are going to have this thing dialed in! Well, Keep up the good work man!

Natty light bottles? Man, when I was in college we could only afford the cans. But.....I was riding a brand new 04' GSXR600.....so thats most likely why.

Haha, yea man no worries... and yea around here natty bottles go for the same as natty cans, love me some Tuscaloosa.

The bad news: I got everythin back together, and in my usual fit of cursing and knuckle busting got the carbs back on, airbox and battery and everything else hooked up, took way to long in my opinion as i was super excited to fire it up. what did I find?
a) I had put the two sets of bowls on criss crossed (drain screws facing in)  ...
b) I remember while cleaning  that I got two of the float needles mixed up and went with the best I could remember as to which was which, figuring I had a 50% chance they were right. wweelllllll I was wrong. got everything hooked up, turned on the petcock, and wouldnt you know it, two of the bowls started to overflow.

SOOO, I'm skipping my 2 oclock class and fixing this #$%*.. its personal now. Hoping its not too much of an issue to pull the carbs with full bowls, as I now am unable to get to the drain screws  

[flybox1]

They probably overflowed because the floats were stuck.  this would be the time to tap on the bowls with the handle of a screwdriver, or something. that usually frees them up.  (I had to do this over the weekend when i put my tank back on)  
nah, ya dont have to drain the bowls before, but you might have a little spillage in the process.  i dont drain them before removing the carbs.  you can open the bowl screws once they are off.
if you have to take them off to switch bowls, just verify again the floats are at 24mm.
when you get everything back on, and are ready open the petcock, do it for a quick second, shut it off, and then tap on all the bowls, then, turn the petcock back on.  this usually frees up the floats before the floor is covered in gas...

[davis96]

They probably overflowed because the floats were stuck.  this would be the time to tap on the bowls with the handle of a screwdriver, or something. that usually frees them up.  (I had to do this over the weekend when i put my tank back on)  
nah, ya dont have to drain the bowls before, but you might have a little spillage in the process.  i dont drain them before removing the carbs.  you can open the bowl screws once they are off.
if you have to take them off to switch bowls, just verify again the floats are at 24mm.
when you get everything back on, and are ready open the petcock, do it for a quick second, shut it off, and then tap on all the bowls, then, turn the petcock back on.  this usually frees up the floats before the floor is covered in gas...

Do you think its still possible that my floats are stuck, even having just torn everything apart and cleaned/checked for free moving floats etc? If so, I have not attempted to remove the carbs yet so can I just tap the bowls and see what happens?

My floats are set at 21mm (per the Honda CB350F-CB400F Shop Manual)... where did you get the measurement of 24 from?

[flybox1]

the floats can get stuck anytime, and yes, tap on them and then turn your fuel back on.  the floats will then press up against the float valve to shut off the fuel.  if this doesnt work, you gotta pull them again and check the float valve is closing completely.
i went with 21mm's first(clymer & shop manual) and still had overflowing bowls.  HondaMan on here helped me greatly and said 22-24 was optimal for these carbs.  
24mm's was the magic #.

[flybox1]

Quote from HondaMan below....

"Turn the carbs upside down, then make sure the arm moves freely (no burrs raised on the edges of the float supports on the carb body: remove with a razor blade if yours has some burrs there). Lift the float at its outside edge of the float itself, then lower until it just takes out the slack in the tiny plunger. This is the right amount of preload, i.e., none. Bend the tang until the float height is correct at this position.

I often shudder, listening to some of the advisors I see on the forum, talking about how to set floats. They usually also are posting about the problems they are having with bowl overflow afterwards, sort of like your situation... 

If you are not real confident about the float setting value, go to the next "even" MM setting. I honestly don't ever remember any Honda having an odd number as the float height, so I suspect the 21mm figure you have might really be 22mm (or 24mm). The best way to check the end result is a little complicated, but 100% effective: install a thin banjo bolt with a 6" long piece of clear tubing onto the drain screw of the float bowl. Then install the carb and apply fuel while holding the clear tubing upright to see how high the fuel goes (make sure the bike is level for this test). When full, the fuel level should be 4mm from the carb body side of the gasket surface for all Fours. I had to make my own banjo bolts, though..."


i did this but just insterted (screwd' in) a 10" piece of clear tubing the drain screw hole, and used this to check fuel level.   24mms is right on, and no more overflows.

flybox1

[davis96]

Ok, so I think that tapping one of the two leaking bowls (the one on the outside, non-choke side) made it stop, since there were no drips or anything.
But the other one (inner one on the choke side) still leaks. It doesnt appear to be coming from the overflow tube, though, which is where it would come out if the float were stuck, correct? The body of the bowl itself is actually wet with gas, making me think gaskets... If the gaskets were bad, wouldnt gas come out of the overflow tube before being forced out the gaskets?? I feel almost 100% certain I checked and cleared all the brass overflow tubes before reassembly. Is there anything that could be causing such a leak?

[flybox1]

it could be:
1. the bowl gasket not seated properly so its leaking where it should be sealed.
or 2, yes, the float valve on that one not sealing when the float depresses it.
3. the fuel line to the carbs isnt on tight or the passages between the carbs might be old/cracked, and may need some attention.

Petcock leaking and gas flowing down outside of fuel line, or a cracked fuel line, and dripping off #2 carb body?

[fletcha221]

Davis,

Beat the living bejesus out of the bowls with a rubber hammer.....should fix it. Hey, by the way, did those tubes come out fairly easy? I bought my carbs off a "Running" bike......which is in hein sight.... was a flat out lie. So, it literally took me 3 sets of carbs to build one good set. The only thing that wasnt replaced from the stock "Running" carbs were the tubes.......now you have me thinking I should check them. Crap.

A lot of my customers are from Alabama....they always tell me about how inexpensive things are down there. Lucky! Philadelphia is an expensive place to live.

Greetings from Miller country.

[davis96]

Davis,

Beat the living bejesus out of the bowls with a rubber hammer.....should fix it. Hey, by the way, did those tubes come out fairly easy? I bought my carbs off a "Running" bike......which is in hein sight.... was a flat out lie. So, it literally took me 3 sets of carbs to build one good set. The only thing that wasnt replaced from the stock "Running" carbs were the tubes.......now you have me thinking I should check them. Crap.

A lot of my customers are from Alabama....they always tell me about how inexpensive things are down there. Lucky! Philadelphia is an expensive place to live.

Greetings from Miller country.

Im givin her a good once over as we speak, hah. To be honest I think that is the exact case with my bike, regarding the tubes; the PO cleaned everything  except the tubes... yea its a sliding scale of expense though, some things are wildly cheap, others that would be available in bigger Northern cities on the cheap will cost you an arm and a leg.

[davis96]

Also, for what its worth: the two that were leaking seemed to be doing so from somewhere about the gasket line of the bowl... Above the bowl is a touch wet as well, and I just pulled one of the intake boots and it was wet inside there as well, which may in fact be where the gas is coming from in the first place

I forgot to mention, on the bowl that is especially leaky, I just replaced the pivot pin, and the float moved freer than any of the others, simply swung around in the wind.. so i dont think its that. BBUUTT, I remember one of the floats being a great deal higher than the others (with carbs upside down, of course).. but i thought it was just a fluke and returned it to the stock setting.

[fletcha221]

Hey man, those bowl gaskets are terrible. I ended up replacing all of them. The ones in there before always leaked, even though I had really torqued those screws down.

[fletcha221]

dude, sounds like your overflow isn't working, the gas has nowhere to go put out the intake....right?

[davis96]

dude, sounds like your overflow isn't working, the gas has nowhere to go put out the intake....right?

that does make sense to me... but I just went and ran some safety wire up in the overflow tube to check for obsructions and there were none, even came out with gas on the wire. Then I turned the petcock on to check and carefully observe where the leak was coming from. It starts from the top of the bowl (NOTE: I cant see if it is coming from the seam between carb body and bowl, though), then it sheets down the inner side of the bowl, til it drips from the drain screw.. but not FROM the drain screw or out of the overflow tube.. I'll try to take a video in a minute and post it, see what you guys thingk

[fletcha221]

the simple answer is usually the right one........it sounds like a leaky bowl. Mine did it, are you SURE you really tightened those bowls down PFT (Pretty F*Cking tight?)

[davis96]

the simple answer is usually the right one........it sounds like a leaky bowl. Mine did it, are you SURE you really tightened those bowls down PFT (Pretty F*Cking tight?)

I'll go back and re-tighten them in a sec (have to go buy a shorty/right angle phillips first).. But it still baffles me how the gas could make it out of the seal, yet the overflow tube is unobstructed and dry?

Its going to be SUCH a bummer if I have to order parts to make these carbs work.. it sucks that motorcycle shops wouldnt have these parts in stock for such an old bike

[flybox1]

if you are wet above the gasket line, check your carb-to-carb passages.  i bet one is crap.
if just the bowl, check the gasket is not pinched and in its proper place. sometimes they can be a bugger to get seated properly when putting the bowls back on.  dry them out really well so they shrink after "gas expansion"
PFT is great, but dont strip the screws....

[fletcha221]

Yea......the parts are hard to come by, and a speed shop or honda dealship isnt going to have them either. www.bikebandit.com has always done well by me. Hey, I know most of the guys say dont overtighten the screws, but you really really need to snug them down if you are using the old gaskets, I finally just gave up and ordered the kits. From here: (great site by the way) http://www.jerryscycles.com/catalog/i35.html, but I think you CAN find the gaskets for sale on their own.

[fletcha221]

Also, Why did Honda have such a penchant for Phillips screws? " hahaha good ruck wit dis you stupid roundeye!" Good lord, I think I've stripped every single screw head on my bike at one point. Thus the reason that the case and sprocket cover have a set of Allen bolts waiting for them.

[fletcha221]

also, in your pictures, the one gasket looks like is has seen better days.

[davis96]

Yea i feel ya on the phillips nonsense, my drive gear cover has absolutely zero threads left in the screws.. hope i dont have to open it up hahah..

As far as the gaskets go, they really did seem in fine shape to me, and though one of them wasnt seated properly before.. i straightened it out and it fit like a glove afterward.. but if i determine the leak is coming from the gasket im going to pic up some gasket seal at the autoparts store.

[davis96]

Update: I think the very end of my fuel line (into the carb) is leaking ... also a #$%* to get to. Heading to the O'reilly's down the street to get a replacement.

And for those curious, here is the bike giving us alllll the trouble:

she's not too much to look at, but she'll be a great little runner, and i won't be able to get up enough speed on it to kill myself (as of yet the bike couldn't take the hat off your head at full acceleration)

oh and the pride of my happenstance fleet of helmets, goldie

[fletcha221]

Dude,


Cool bike, I dig the wrap! What kind of exhaust is THAT!? The main fuel line, replace it, its like 2 dollars from any auto parts store. I used a zip tie just to make sure its on there snug. I side with flybox, the feeds between the carbs are s*it. I replaced all of mine, they get very britle and crack.

Good luck with the offset screwdriver, its impossible to get in there.

Careful with the gasket sealer, if that gets in the bowl and in the carb.....epic sh*tshow.

I have to say, you are starting off with a much better bike than I did!

[davis96]

Dude,


Cool bike, I dig the wrap! What kind of exhaust is THAT!? The main fuel line, replace it, its like 2 dollars from any auto parts store. I used a zip tie just to make sure its on there snug. I side with flybox, the feeds between the carbs are s*it. I replaced all of mine, they get very britle and crack.

Good luck with the offset screwdriver, its impossible to get in there.

Careful with the gasket sealer, if that gets in the bowl and in the carb.....epic sh*tshow.

I have to say, you are starting off with a much better bike than I did!

Ha thanks bro,
   Its a budget build to say the least. I'll be building a fiberglass seat and giving her a new paintjob over spring break. The exhasut is a MAC 4-into-1, it came on the bike. I did replace the fuel line, along with the inline filter, but had to leave to meet with my business partner before I got a chance to finish and start it up.. so tomorrow we'll see if it all worked... I really do think my only real issue was the leaking main fuel line. If everything works, there will be no need for any sort of screwdriver as I wont be needing to pull the bowls at all  same with the gasket sealer, i'll burn that bridge when/if I get to it. And I don't know, the bike was ok when I bought it but ended up need alot, guess that what i get for buying a 500 dollar bike