Author Topic: cb350f running issues + pics (new video on page 5) (Read 16031 times)

scottly · « **Reply #125 on:** February 08, 2010, 05:56:49 PM »

Hi, new here. Been following this thread for a while now. I suspect you have solved your original problem with the flooding carbs, but your plugs are fouled. Been there, done that. You can't clean fuel fouled plugs with a wire brush or carb cleaner, at least in my experience with severely flooding carbs. The best fix I have found is to use a small, pencil type propane torch and heat the insulator evenly around the center electrode until it starts to glow red. If, after cooling, the ceramic insulator looks white to brown, the plug is probably ok. If it has a grey, graphite look, I wouldn't trust it...
Hope this helps, and good luck..
Scott

camelman · « **Reply #126 on:** February 08, 2010, 06:00:09 PM »

I'm with scott on this one. Replace those plugs, and make sure your advance unit is working. I just read your post about not getting past 6k rpm, and that sounds like mechanical advance to me. Take it off, clean it, put a little grease on it (not WD-40) and I bet it winds up just fine. Take it easy on that advance though. You don't want to force any part of it.

Camelman

scottly · « **Reply #127 on:** February 08, 2010, 06:15:54 PM »

I say first things first, fix the plugs, then worry about the little things like carb sync (only has it's greatest effect at idle), point gap (hey, if they're makin and breakin, they're workin),
and timing and advance (rpm related issues)

davis96 · « **Reply #128 on:** February 08, 2010, 06:33:40 PM »

Quote from: scottly on February 08, 2010, 06:15:54 PM

I say first things first, fix the plugs, then worry about the little things like carb sync (only has it's greatest effect at idle), point gap (hey, if they're makin and breakin, they're workin),
and timing and advance (rpm related issues)

You think my plugs might be FUBAR'd because of the overflowing bowl and what not? Only reason I ask is because they really are brand new plugs, and before the last time i started it up (after doing the timing), I cleaned them pretty good and sanded the #$%* off the electrode and what not. I'm not like being a tightwad here, I dont mind buying new plugs, but I was just wondering if the bike running that way could really screw over a set of brand new plugs..

NickC · « **Reply #129 on:** February 08, 2010, 06:40:05 PM »

I always had a couple of plugs on hand when I was first tuning my bike after a rebuild. They would foul up pretty quick. Once I got everything right, no issues. It won't hurt to check them out.
Roll Tide, I'm originally from Mobile, my little cousin is currently attending UA

scottly · « **Reply #130 on:** February 08, 2010, 06:42:31 PM »

In a word, YES. Well, not totally FUBAR. That's why I passed on the propane torch tip to you.
If the INSULATOR around the electrode can be burned off, you can re use the plug/s

mlinder · « **Reply #131 on:** February 08, 2010, 07:13:24 PM »

OK.

Dunno where you are at on tuning, but, you need to do these:

Valve adjustment
points
New plugs
Synch carbs

The tiny sohc4's are very finicky about all of these. Bike must have these done to run correctly.

hoodellyhoo · « **Reply #132 on:** February 09, 2010, 07:56:14 AM »

Here's a cheap way to do static timing: get a small radio, put it near the bike, and tune it to any AM postion with just static. With the ignition switched on, slowly rotate the crankshaft. You will hear distinct pops from the radio as the points open and close. Adjust the points so that they pop on the timing marks.

Since you are having revving issues though, I would highly recommend finding a timing light to use to check that your advancer mechanism is working.

fletcha221 · « **Reply #133 on:** February 09, 2010, 08:24:05 AM »

....and if that dosent work, you are going to need a flux capacitor and 1.1 giggawats. That should get her to 88.

hoodellyhoo · « **Reply #134 on:** February 09, 2010, 11:09:08 AM »

Quote from: fletcha221 on February 09, 2010, 08:24:05 AM

....and if that dosent work, you are going to need a flux capacitor and 1.1 giggawats. That should get her to 88.

Do you think they make the lightening rod adapters for the 350f though?

fletcha221 · « **Reply #135 on:** February 09, 2010, 11:24:10 AM »

Depends on the clock tower I suppose.

I'd travel back in time and punch the retard who designed the oil filter bolt......and the cam chain tensioner.

davis96 · « **Reply #136 on:** February 09, 2010, 11:29:05 AM »

Here's a question, I have to remove my wheels tomorrow go go have new tires install (my old ones, probably factory originals, finally #$%* the bed).. While they were off I wanted to make them look more presentable.

The chrome on the rim looks ok, but even after scotchbriting and hitting the spokes with a wire wheel, they are still doodoo brown. Ideas?

fletcha221 · « **Reply #137 on:** February 09, 2010, 12:16:15 PM »

Dial 1900-976-DO DO?

Go get stuff called navel jelly (really, thats what it's called), SOS pads. If you cant find Navel Jelly, use wd-40.

Then, wax the living #$%* out of it.

camelman · « **Reply #138 on:** February 09, 2010, 03:46:06 PM »

Sodas of any type works too. Even soda water would work. You can use it with a heavy nylon brush or wadded up aluminum foil.

You might get charged $20 to pull the front axle at the tire shop (that is a common charge on our bikes). So, try to get that front axle off before taking it in there. They need it out to balance the wheel. Use an impact wrench if you have one handy. If not, then use the largest diameter screwdriver you can find that is not yours... because you are likely going to bend it. You'll see what I mean when you get the wheel off. If it doesn't want to come off, then just pay the $20. They'll have a trick or two.

Camelman

scottly · « **Reply #139 on:** February 09, 2010, 04:31:10 PM »

davis, since you have shifted your focus to wheels and tires, may it be assumed your running issues have been solved?

davis96 · « **Reply #140 on:** February 09, 2010, 05:24:13 PM »

Quote from: scottly on February 09, 2010, 04:31:10 PM

davis, since you have shifted your focus to wheels and tires, may it be assumed your running issues have been solved?

Not quite, I was more just asking a question I had on my mind today, since it was too damned cold to work on the bike (it is supposed to snow on friday... SNOW!... in ALABAMA!).

I still have yet to perfect the timing, but I suspect that with proper timing and tappet clearances set, it should run mmuucchh better.

Could someone tell me what the spark advancer is, or what I am looking for? I dont recall my manual adressing the topic..

NickC · « **Reply #141 on:** February 09, 2010, 05:39:35 PM »

Remove right side cover, you'll see the points/plate. It's held by 3 screws, loosen those up and rotate

scottly · « **Reply #142 on:** February 09, 2010, 05:45:33 PM »

davis, the timing doesn't have to be perfect, nor the tappets, for a motor to run even half way decent, let alone like crap, as in has problems reaching 6500 rpm in neutral. Have you changed, or cleaned the plugs yet?

camelman · « **Reply #143 on:** February 09, 2010, 05:52:57 PM »

The spark advancer is a mechanical unit that advances the timing as the engine speeds up. The unit has spring-loaded weights in it that spread out as the engine speeds up (the unit is attached to the crankshaft). The weights move a mechanical assembly to make the spark plugs fire sooner. If the unit is gummed up, then it will not advance the spark, and your engine will not make full power at higher rpm.

At idle, your spark plugs fire somewhere around 6degrees before top dead center (TDC) (anyone have the actual degrees?). This is to provide time for the combustion to occur before the power stroke begins. At higher rpm, the combustion process must start with the piston even further from TDC to reach optimum pressure at the beginning of the power stroke. These are just physical limitations of living in a physical world. I don't think the inhabitants of Tron need spark advance units. ;-)

Camelman

HondanutRider · « **Reply #144 on:** February 10, 2010, 08:35:08 PM »

Davis,

All the items being mentioned are important for tuning in order to have a good-running motor. However, with the problem you are having and in light of the fact that you had the carbs apart to clean them out, I wonder if you may have installed the valves (throttle slide piston that holds the needle) incorrectly. You might have a couple switched so that the cut-out side is not facing the inlet side of the carb body. From the side where the air flows in from the filter, this valve should have a cut-out or notch on the bottom. There are two different versions - a left and a right side one, and it is possible to install them the wrong way - i.e. switching them so that the notch faces the wrong side. If that is done, very poor running is the result, particularly at idle.

davis96 · « **Reply #145 on:** February 14, 2010, 01:46:20 PM »

Quote from: HondanutRider on February 10, 2010, 08:35:08 PM

Davis,

All the items being mentioned are important for tuning in order to have a good-running motor. However, with the problem you are having and in light of the fact that you had the carbs apart to clean them out, I wonder if you may have installed the valves (throttle slide piston that holds the needle) incorrectly. You might have a couple switched so that the cut-out side is not facing the inlet side of the carb body. From the side where the air flows in from the filter, this valve should have a cut-out or notch on the bottom. There are two different versions - a left and a right side one, and it is possible to install them the wrong way - i.e. switching them so that the notch faces the wrong side. If that is done, very poor running is the result, particularly at idle.

I kept the slide separated and knew which one went in which carb, and as far as I know, with these carbs, the slides can only go in one way, due to the notch running down the side of the slide that corresponds to the little nipple thing (cant find the word) residing in the carb body where the slide is placed.

After adjusting my timing, it does run better, and once I get my new tires on Monday, hopefully I'll be able to fiddle with the timing a little more, possibly advance it a touch, and fine-tune it with a timing light if i can beg/borrow one around here.

midnightrider · « **Reply #146 on:** June 14, 2010, 08:32:54 AM »

Davis,

Did you ever get everything right?

I am working on a 72 350F. I cleaned and rebuilt the carbs, replaced boots, set timing, synched and ran great for a short period of time. I flooded it bad (I think partially due to running the carbs dry, refilling and overflowing because of stuck float valves) the other day and it hasn't ran right since then. Wont idle down properly...idles at different levels with the idle screw never changing and the throttle linkage in the idle position. Also, header #3 is not as hot as the others and I do not think that is was this way before.
Everything just hit me at one time. I think that I need to check the plugs for fouling.

I'd like to hear about how you got yours right though. Fill us in!

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Author Topic: cb350f running issues + pics (new video on page 5) (Read 16031 times)