Pamco install - sparks but won't fire

ljevans

ljevans

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I've just finished installing my pamco kit with the e-advancer. i've wired it up as per these instructions

http://www.yamahaxs650.com/installation.htm

I tried to fire it up tonight but it wouldn't start. i got about 3 backfires when i first started so i moved the timing a little one way and then the other but no luck. after that it wouldn't even backfire. no life at all. i double checked my wiring and then i checked for spark. it is infact sparking. I've tried moving the timing all over the place but no matter where I put it it doesn't show any signs of wanting to fire. I have the coil bolted to the frame via the home depot grounding clamps but i haven't run an additional ground to the coil. is it possible that the coil needs a dedicated ground wire running to it? like I mentioned it does spark but perhaps its weak? I had the bike running pretty well about a 1-1.5 months ago but i haven't started it since. i didn't fire it up before i installed the pamco so im not sure if something else has possibly developed in the time it was sitting? it has good compression, I had the carbs apart for a cleaning just before the last time that i ran it and I rode it for 20-30 min before i parked it and it was running well except for the mechanical advance hanging up but since i was going to the pamco kit i didn't bother messing with that at the time. I drained the fuel tank and put fresh gas in it right before my last ride as well. the tank is pretty low on fuel now but I should think it's still good after only 1 month or so of sitting. I also pulled the fuel lines off the tank and fuel poured out so it doesn't appear to be obstructed or out of gas.

it's a 1977 xs 650. It has a fresh battery (about 2 months ago) AMC regulator, radio shack rectifier, new alternator rotor and now the pamco ignition. Any advice would be greatly apprecaited.
 
ljevans said:
Also can anyone recommend what spark plugs to run with this system?
Click to expand...

You are on the right track with this question. The non starting problem could just be the plugs. I would recommend the stock NGK BP7ES or Autolite #63.

Check the three locating pins to be sure they are there. There is one pin on either end of the advance rod and one in the cam on the right side used to locate the advancer replacement. The advancer replacement cap must be unable to move if installed properly. Take a look at the installation instructions to see the recommended starting position for the plate. www.yamahaxs650.com

Also, you should be able to see the timing with your timing light even as the engine turns over trying to start.
 
Pete,

thanks for the reply. I will replace the spark plugs today and i'm going to fill it up with fresh gas. I didn't have a multimeter with me but I took the battery out last night and brought it with me to work to charge it and i found that it had only 11.6v! I seem to remember reading somewhere that this ignition system will work down to around 6v? Regardless the battery needs charging but I was hoping this will be my issue. I rode the bike when I first bought it and the charging system wasn't working (which i didn't know at first) and the bike died while running and wouldn't start back up again. I'm hoping that the low battery is my main problem. Ill replace the plugs, put it fresh gas and the charged battery and hopefully that will get it going. the plan was to take it for it's first proper ride tomorrow so hopefully i get some luck today!
 
ljevans,

Well, you're going to the wrong parts store. The BPR7ES is the resistor equivalent to the BP7ES, but it will work in this case.
 
Well, good news. I replaced the plugs, put in fresh fuel and the charged battery and it fired up and ran first kick. I set the timing and took her for a rip. It seems to only be firing intermittently on the right cylinder but the left cyl seems fine. I noticed that my right carb is dumping fuel out of the drain tube so I presume that I need to lower the level in the float bowls. Can this cause the cylinder to miss fire due to over fueling? The old plug from the right cyl was definitely more fouled than the left.
 
In short yes an over rich mixture caused by an overflowing carb can cause the cylinder to miss. The problem may be in the float setting, trash in the float valve, a hole in a float if you have the brass floats or a binding float.

Quick questions, when you parked it did you leave the fuel in the float bowls? Do you have an in line fuel filter? You may have picked up some debris in your old gas.
 
Hmmm... I'll take them apart and set the float levels correctly. it does have the brass floats. I had the fuel off when I parked it but I didn't drain the float bowls. I don't have an inline fuel filter but I will pick some up.
 
Also it was running intermittently on the right cylinder before I parked it but I attributed that to the shoddy ignition. I could hear it tonight cutting in and out when I rode it. Both headers are getting hot but the left one is hotter
 
Well I pulled the carbs apart and both the floats have fuel in them (brass floats in BS38 carbs). I've order 2 new floats, 2 new needle and seats, 2 float bowl gaskets and some other misc doodads from xs650 direct. hope to see that stuff by the weekend and get her back together. Thanks everyone for the help.
 
pamcopete said:
ljevans,

Well, you're going to the wrong parts store. The BPR7ES is the resistor equivalent to the BP7ES, but it will work in this case.
Click to expand...

I'm going jack this thread with a question on plugs.
I'm having a hard time locating BP7ES and everywhere i call they are trying to sell me BPR7ES. I'm using resistor plug caps so i've read you can't use both. Either one or the other.
I just want to test my wiring harness so will the BPR7ES be fine. ALso the third store I called said they change the no. of the BP7ES with just 5534. Is this right or is he feeding me a load of crap?
 
I "had" been getting the "correct" BP7ES in stock at my local NAPA. I think I bought some from them last summer.
Like said above the R plugs OR the resistance caps not both for use. To test the harness the R's should spark.

Ljevans can you report on the float quality from 650 direct? I have been buying the OEM floats from 650central. Heard bad things about the Mikes knock off floats in the past.
 
Hardyrd - I was getting the same run around here in BC. I just ended up getting Autolite #63's from NAPA and they work great.

gggGary - Damn! I should have done more research on these floats. Hopefully they are ok. I will install them and let you know how they go. I'm sure they'll work ok at least for a while but I didn't really look into alternatives for floats.
 
The usual bitch about the floats was sloppy fit on the shaft.

It's not just that Chinese manufacturing is bad, it's they way they cheapen the design till it doesn't function well..........
 
yeah that seems to be an issue in all areas. I fly model airplanes as well and there's lots of offshore parts available for them too. some work well some do not. I'll let you know how these floats work for me. I should have them by friday so i'll probably install them over the weekend. We're in a bit of a cold snap here now so it might be a week or two before i get any riding done.
 
ljevans,

With all that extra gas running through the carb, be sure to change the oil as it's possible some gas got past the rings into the crankcase.
 

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