|
|
Post by detroitmuscle07 on Nov 5, 2008 20:00:35 GMT -5
I finally got my new petcocks and was all excited about getting the bike running after the pamco relay installation ( thinking that a voltage drop at the coils might finally be the source of my rich running problem.) I double checked my float levels while the carbs were still off the bike and they looked beautiful. I set my mix screws to the factory spec (3/4 out for 1973 BS38's) When I started it, the bike seemed to be running on 1 cylinder at idle speed, so I shut it off and pulled the plugs. My left plug (the side that always gives me trouble) was soft carbon fouled and wet after 20 seconds of idling. I decided to take off my spark plug caps and look at my wires and I found that the copper core connections from wire to cap didnt look healthy. I trimmed both of my plug wires to expose more copper and reinstalled my plug caps. I restarted after trying to get equal throttle openings and the bike still idled like crap and my left side pipe was not firing hard at all. In fact, my left pipe felt like it was sucking my hand in a bit when I placed it over the pipe while it was running. My right side wasnt running 100%, but it was pushing alot harder than my left. I shut it down once again and turned my mix screws in about an 1/8th turn and tried the match throttle openings with the throttle screws once again. When I tried to kick the bike back to life this time, the kick lever flew back up and slammed into the bottom of my foot. Thinking that it might just be upset at me, I tried to kick it over again. This time it really came flying back up and bruised the bottom of my foot pretty damn good ( I wear Chuck Taylors.) Ive heard this is usually caused by a timing issue, but I have Pamco universal ignition timed pretty dead nuts. I dont know whats going on here! No matter what I do, the left side alwayssssssssss acts up and fouls plugs. I have installed/bought/tried every single suggestion ever given to me in order the cure this problem. The bike is going on Craigslist tonight, Im sick of this thing. Anyone near the Florida panhandle is welcome to come check it out. This is about my 15th post about the same problem. Just to clarify, these are the steps I have taken to cure this problem. Let me know if I might have missed something;
- Pamco Ignition timed correctly
- Proper float height
-Completely rebuilt carbs (yes, I replaced the needle jet and o-ring too)
-Relay to igntion coils so they get full battery voltage
- Im running short pipes and pod filters with the carb jetting 1 step up on pilots/2 up on mains.
-One step hotter plugs (bp6es) while Ive been trying to sort this out
- More anger/voodoo/whishful thinking than you can imagine
Why the hell does the left side always always always foul plugs so fast? If my dual output coil was the problem, wouldnt both sides act up? Can too much oil and maybe gas in the sump cause crazy problems? Im going to the store to buy beer. I dont even want to think about motorcycles right now.
|
|
|
|
Post by pamcopete on Nov 5, 2008 21:56:05 GMT -5
detroitmuscle07 Sounds like a bike with real personality! Well, attitude anyway. I read PAMCO a couple of times, so I thought I would chime in here. The PAMCO ignition is dependent on the advance mechanism and advance rod for accurate timing. The advance mechanism is subject to wear, specifically, the little tabs on the weights that engage the slotted disk wear down and can allow the timing to wander from a few degrees retarded to a a few degrees advanced. Start the engine and check the timing. Hold your finger on the PAMCO rotor with the engine running. The timing should not change. If it goes to a retarded position, then the little tabs on the weights are worn out and/or the springs are weak. If that is the case, then it's possible for the timing to also go to an advanced position as well, and that could explain your sore foot. However, it would not explain your wet left cylinder. I'll leave that to the carb experts.....  |
|
|
|
Post by tomterrific on Nov 6, 2008 7:47:27 GMT -5
Too much oil? Gas in the sump? Simple, the carb is leaking and gas in running into the cylinder! The way gas gets into the float bowl is through the needle and seat. Either the needle is not sealing the seat or the gas is flowing around the seat where it fits in the float bowl. The float level could be way too high also.
Kick back? Simple, the timing is too advanced because of a sticky mechanism. Have you greased the advance rod and mechanism? Check that the advance moves smoothly and pulls back to the retarded position for starting ('cause it isn't and that is why bikes kick back).
Tom Graham
|
|
|
|
Post by detroitmuscle07 on Nov 6, 2008 8:57:22 GMT -5
Needle not sealing? Those were replaced with the carb rebuild kit. Gas flowing around the seat where it fits in the bowl? Im not sure if I follow you on that. Float level too high? I was under the impression that the higher your float level, the less gas inside the float bowl. I set it to 25mm.I will change the oil today and take special care to not overfill the sump.I have the early style dipstick and Ive heard the oil levelneeds to be lower than the mark on the dipstick. One more thing that I think I have mentioned to someone, when I tirun my carbs right side up with the float bowls off, the floats drop down pretty low. It seems like there should be some sort of tab on the floats themselves that make contact with the posts and stop the floats from dropping down. Hopefully I Iexplained that in a way that makes sense. Thanks!
|
|
|
|
Post by detroitmuscle07 on Nov 6, 2008 9:04:44 GMT -5
Forgot to add this to my previous post;
When the float bowl are removed and the carbs are held rightside up, the foats drop down and this allows the float needle to fall out of its seat. It does not fall completely out because the tab that controls float height stops it. It does come out of the seat a considerable ammount though. Is this normal? Seems like that shouldnt happen, but what do I know?
|
|
|
|
Post by grizld1 on Nov 6, 2008 9:44:14 GMT -5
In use, drop of the float is limited by the float bowl, and this is as it should be.
This grief has persisted through two carb sets, so I'd advise you to look at that new float valve and at the ignition. A new float valve doesn't guarantee a good seal. Small burrs or other defects are sometimes present, so check function and fuel level with a sight tube (BTW you're right, higher float level=lower fuel level). Even if they're new, check impedance in plug caps; Pete, correct me if I'm wrong, but I'd guess your ignition requires 5Kohm caps like other electronic systems?
|
|
|
|
Post by detroitmuscle07 on Nov 6, 2008 10:21:06 GMT -5
Maybe the caps are wrong. Ive never checked their impedance. The previous owner had the same fouling problem and Im using the caps that he had on the bike. Pretty much everything else that could be replaced regarding this peoblem has been changed. The only things I can think of now are the cap and float valve assembly. Good thing I can purchase caps at the local auto parts store if I find them to be incorrect. I wonder why its my left cylinder that always seems to be more problematic that the right.
At one point last night, I had the mix screw all the way in on my left carb and the pipe seemed to be running harder, but it did not quit. Regardless, I could see a consdierable ammount of black smoke coming from both pipes.
|
|
|
|
Post by grizld1 on Nov 6, 2008 11:20:42 GMT -5
I keep coming back to the fact that your problem's more severe on the left side, where the choke lives. The plunger in the carb set I sent you looked good visually and appeared to be sealing when checked on the bench, but the rubber tip is 35 years old. You might see what happens if you push down directly on the choke plunger. If it's leaking that should make a difference.
|
|
|
|
Post by detroitmuscle07 on Nov 6, 2008 11:45:15 GMT -5
Dick,
I tried that last night too, but didnt mention it in my post. It did not seem to make any difference at all.
|
|
|
|
Post by 5twins on Nov 6, 2008 12:46:02 GMT -5
If the plug caps are originals, it's very possible they're going bad. Original caps had a rather odd rating of something like 9K ohms. It will start to climb up past 10, 12, 15K ohms, etc. when they go bad. That chokes off your spark. 5K ohm NGKs are what most of us replace them with. If not available at your auto parts store, any cycle shop should have them or could get them for you. The ones you want would be #LB05E or F. Try to get the "F" version if you can as that fits on the threaded stud on top of the plug and grips better in my opinion. The "E" version is for that aluminum cap nut that screws on the plug top and I don't think they grip as well.
|
|
|
|
Post by detroitmuscle07 on Nov 6, 2008 12:56:44 GMT -5
They are not original plug caps, they are NGK's. Im not sure if they are the #LB05E/F's though. I will check that when I get home. I do know that they fit the terminal stud and not the cap nut.
|
|
|
|
Post by detroitmuscle07 on Nov 6, 2008 18:54:04 GMT -5
The caps are LB05FP's. They say 5k ohms on them. Is there a difference between LB05FP's and LB05F's?
|
|
|
|
Post by grizld1 on Nov 6, 2008 18:55:38 GMT -5
No matter what caps they are, take a multimeter to them and ohm them out.
|
|
|
|
Post by detroitmuscle07 on Nov 6, 2008 19:04:05 GMT -5
Dick,
Can you give me the run down on testing the caps again? I dont have a meter here anymore, my buddy took back the one I was borrowing from him. I will try to borrow one from someone at work tommorow. Thanks!
|
|
|
|
Post by pamcopete on Nov 6, 2008 21:35:37 GMT -5
Even if they're new, check impedance in plug caps; Pete, correct me if I'm wrong, but I'd guess your ignition requires 5Kohm caps like other electronic systems? grizld1 Sorry, I didn't see your question til now. Yes, the recommended resistance in each plug circuit is 5K Ohms obtained in one of two ways: 1. Non resistor wires, 5K caps, non resistor plugs (NGK BP7ES) 2. Non resistor wires, 0 K caps, resistor plugs (NGK BPR7ES) I no longer recommend resistor wires because their resistance is generally too high. |
|
