are my Ignition coil readings ok?

[zekkfett]

May 9, 2013 14:15:38 GMT -6 @brendan said:

I am new to motorcycle engines. I tested my coils and got the following results:
Primary was 3.5 and 3.6, specification is 2.1-3.2 ohms
Secondary was 16.5 and 16.65, specification is 10-16 k ohms

how bad are these coils? Will I get away with them? Should they be replaced?
thanks in advance

Brendan

You are on the FINE line there... I would be more worried if the resistances are lower than spec. (Windings are failing and grounding out, giving a lower resistance)

What exactly was your reason for testing the coils in the first place?

[Deleted]

thanks

[zekkfett]

May 10, 2013 9:04:57 GMT -6 @brendan said:

I am investigating why my engine is not running smoothly. I worry about my electrics because I jump started my bike from my truck and I want to make sure i have not fried my system. I disconnected the IC Igniter and tested all the terminals following the chart in the manual (page 15.17).
I do not get a reading from terminals 4 and 5. If there was a problem with the IC Igniter, alternator, pickup coil, would the bike idle smoothly but not work at higher revs?

My background is microbiology and fermenting, engines are a challenge for me but I enjoy solving puzzles. I am learning a lot about how a motor works!

If the truck wasn't running when you jumped with it, your bike should be fine. With most bad coils, as they warm up, they will stop working entirely. If it idles fine, but won't run at high revs, it sounds like 1 of 2 things: as Eagle tells everyone here, do your valve adjustment! Before I adjusted my valves, I could not get over 8,500 rpm. And it's likely you might have dirty main carb jet(s). If the bike has sat for any length of time over a month, with non-treated stabilized fuel, there's a good chance you have some gelled-up gas clogging the main jet(s).

Terminals 4 & 5 on the IC will not have a reading. If you look at 15.17 , 4 and 5 have infinite resistance all the way across. This usually reads as "OC" or " - - " on a digital multimeter.

You say your background is microbiology and fermenting: I myself homebrew. Bikes, boats, and beer are my hobbies! In fact, since I have today off, and it's raining, I'm drinkin one of my house American Amber Ales as we speak.

[Deleted]

thanks for the fast reply, I am new to motorcycles and I confess that my truck was running when i jumped the bike. i should have checked here first. what type of damage could this have done? if i have to replace the coils, are there modern coils I can substitute for the original ones?
I should have spent a month reading every post on here before I did anything to the bike but i was impatient to get running.
B

[eaglerider]

I am sorry to have to tell you this.....if you, in fact had your truck running, no telling what you may have damaged. This bike has a very low charging amperage system...with a running truck, jumping to the bike, you were shooting as much as 14.5 volts, and unknown how many amps, thru the electrical system. When you are trying to do something which you have stated that you know nothing about, please, don't just read thru post, get on here and ask for some help. We are here to help, that is the reason for this forun & parent website.....it will help prevent very expensive mistakes many times. I am not the best at electrical problems, but there are members on here that are very good....tho sometimes, it is sorta hard to help "at a distance" figure out what, if anything has been fried. Best thing to do is to first, check and adjust the valves, and remove and clean very thourghly, the carbs...but do not seperate them from each other. Then, if needed, we/you can go from there.

[zekkfett]

May 10, 2013 12:56:43 GMT -6 @brendan said:

thanks for the fast reply, I am new to motorcycles and I confess that my truck was running when i jumped the bike. i should have checked here first. what type of damage could this have done? if i have to replace the coils, are there modern coils I can substitute for the original ones?
I should have spent a month reading every post on here before I did anything to the bike but i was impatient to get running.
B

Usually, if a bike has damage from being jumped by a running car, it is almost always the regulator/rectifier, and the wires leading to it or from it. If the bike is running as of this point, take your multimeter and get a reading at the battery while running, get a reading of voltage @ idle, then get a reading @ 3500 rpm. Idle should be 12.3 - 12.6. 3500 should be 12.9 - 13.5. If your voltages are much less above or below those numbers, you might have damaged the reg/rect.

Like I said in the last post, if the bike is running, there's a good chance you didn't do any damage. IC's are usually pretty robust, they rarely fail. Also, if your battery is low, the bike will not want to rev, or won't rev very high or rev up very fast.

When replacing a coil, all you have to look for, is a replacement coil that has the same resistance as the stock coil. Accel coils are BY FAR the best aftermarket coils around.

Get a GOOD charge on the battery, from a battery charger (our bikes will not charge at an idle, so you can't charge it that way...). Most likely the battery you have, is more than a couple years old, at which point they start to fail anyway. And do a valve adjustment. Then work from there.

[Deleted]

Ok, here is my progress report:

I adjusted my valves and I am confident that they are correct. They are snug at the widest specification. I cleaned the carbs and put in new jets. I attached a plastic funnel to the gas tube and 'spoon fed' fresh gas into the carbs. I got the bike to start and it idles low at about 800 rpm. it goes on like that for a few minutes and then the engine has a surge in rpms up to 1200 rpm, before settling back to 800rpm. I stopped it and checked spark plugs: plug from #1 piston is ok, clean and tan color, plug in #2 piston is black with soot. Both were cleaned before I started the bike. I suspect that only one piston is firing properly, the low 800 rpm is with one piston working, then after a while the second piston fires for a short time and i got normal idle rpms of 1200. Why is one piston not firing? Could it be a bad coil? My resistence numbers are a little over spec. Maybe I damaged the stator at the alternator that supplies the signal to the IC box to send a spark from that coil?
I took a volt reading at the battery when the bike was idling and got 13.6 volts.

I am confident that this is an electrical problem that I caused by being stupid and jump starting from a running truck. This engine was working was working well before I did that. I look forward to your comments, thanks
Brendan

[zekkfett]

May 13, 2013 11:08:33 GMT -6 @brendan said:

Ok, here is my progress report:

I adjusted my valves and I am confident that they are correct. They are snug at the widest specification. I cleaned the carbs and put in new jets. I attached a plastic funnel to the gas tube and 'spoon fed' fresh gas into the carbs. I got the bike to start and it idles low at about 800 rpm. it goes on like that for a few minutes and then the engine has a surge in rpms up to 1200 rpm, before settling back to 800rpm. I stopped it and checked spark plugs: plug from #1 piston is ok, clean and tan color, plug in #2 piston is black with soot. Both were cleaned before I started the bike. I suspect that only one piston is firing properly, the low 800 rpm is with one piston working, then after a while the second piston fires for a short time and i got normal idle rpms of 1200. Why is one piston not firing? Could it be a bad coil? My resistence numbers are a little over spec. Maybe I damaged the stator at the alternator that supplies the signal to the IC box to send a spark from that coil?
I took a volt reading at the battery when the bike was idling and got 13.6 volts.

I am confident that this is an electrical problem that I caused by being stupid and jump starting from a running truck. This engine was working was working well before I did that. I look forward to your comments, thanks
Brendan

OK, now we have something to go on. Idle at 13.6 is good, so your stator & regulator/rectifier are most likely good. Valve adjustment done. Now onto cylinder #2.

While the bike is running @ 800, pull your #2 spark plug wire off. If it runs the same way, could be the coil. Pop it back on, and pop the #1 wire off. If it dies, it's definitely on the #2 cylinder, and most likely a spark problem.

Black plug means your mixture is too rich, or you could have a bad coil. Using your multimeter, make sure both plug wires are similar resistance. Then make sure you have connectivity across the spark plug. Actually, one of your cheapest fixes could be a new set of plugs. So I'd buy a couple plugs now. Find an extra spark plug that's just lying around, and pop your #2 wire off (leave the #2 plug in the engine, this will isolate the variable of a suspect plug), and put the extra plug in, ground it to the engine, and see what kind of spark you get. If it's no spark, or any other color besides a rich blue color, might be time for a new coil. If you get an intermittent spark when you know that cylinder should be firing, time for a new coil. Also, if you find the coil at fault, try switching the 2 trigger wires on the coil, might help.

Since the plug is black, #2 could also be running WAY too rich to get a burn on the fuel. If you test the electrical for #2, and everything is good, but you still have problems: it's a fuel issue in that carb.

[Deleted]

another update: electrics seem to be good, I got it running better. It starts first time so valves are ok. I left it idle and then I used the throttle. At 3000-4000 rpm the volt reading was 14.5 at the battery. I think I may have dodged a bullet and did not ruin my electrics. No more jump starting for me! After running it ststionary for 10 mins and going up and down the throttle ( without any air filters: open air box) I turned it off and checked the plugs. Both plugs were dirty, it seems the carbs are sending too much gas, I used standard jets (#35 and #125). The main jet needle is non adjustable, I cleaned it and put it back. I screwed in the jets, tight but not over tight. Could it be that the fuel level in the bowls is too high, allowing extra gas to go through the jets? I set the air screw back 2 1/4 turns from the end, which seems to work well.
Carbeuretors are tricky instruments, now I know why new bikes have fuel injection. I am going to buy new plugs tonight to eliminate that variable.
Another thing I noticed when I took the carbs out to clean them, the inside of the rubber boot to the engine and the inside of the metal 'tunnel' going into the engine were covered with a sticky black tar. Is this a symptom of too much gas being used? Should I try to clean this out with carb cleaner?

Thanks in advance,
Brendan

[Blaine]

The needle jet can be adjusted by shimming with 3mm washers.(raising the needles is richer) The 2 1/4 turns out is only a starting point.You need to adjustment them to highest smoothest idle with the engine warm.

[zekkfett]

You should do your plug test runs with the airbox all together. Your results will not be correct if you don't.

If after a test run with the airbox together, you still get a black plug, your float level might be a bit off...


Sent from my LG-LG855 using ProBoards

[Deleted]

Can I send you guys a gift card for Fridays/Applebees? have a few beers on me for your help. I removed the air filters because the engine cut out when I increased the revs when the filters were in. I suspected it was getting starved of air and getting too much gas. When I took the filters out it worked better, throttle up and down without cutting out. I bought new air filters but they have been sitting in my garage for several years unused. I put them on the bike and this is what happens, could new unused air filters deteriorate over time?
I will rig up a clear plastic tube from the drain plug on the carbs and measure the fill hight. I will also measure the float hight. I am close to solving this puzzle.

[eaglerider]

I am surprised that the bike ran as good as u stated without the filters. Normally, this engine runs (if at all) very poorly without filters, and certainly will not rev up even close to normal. Check to make sure both plugs are fireing...u could have a bad plug wire, that fires intermentaly, Idle speed is 1200 to 1250 RPM, when warmed up.

[zekkfett]

May 13, 2013 16:00:10 GMT -6 @brendan said:

Can I send you guys a gift card for Fridays/Applebees? have a few beers on me for your help. I removed the air filters because the engine cut out when I increased the revs when the filters were in. I suspected it was getting starved of air and getting too much gas. When I took the filters out it worked better, throttle up and down without cutting out. I bought new air filters but they have been sitting in my garage for several years unused. I put them on the bike and this is what happens, could new unused air filters deteriorate over time?
I will rig up a clear plastic tube from the drain plug on the carbs and measure the fill hight. I will also measure the float hight. I am close to solving this puzzle.

Sounds like you're getting close. I don't see how brand new filters could go bad... With the filters in and the airbox together, set your air screw and idle speed with a warm bike once it's all together. Then do a plug check. Just a bit more troubleshooting, and you'll be there...

[Deleted]

I would like to get new coils to replace the originals, I went to the Accel site but I am not sure whick ones to get. Do you have a part # for the correct coils. I saw a coil but its a different design, a single coil with two plug wires coming from it. Do they have two single coils similar to the origionals? Thanks

[Deleted]

I bought 2 new spark plugs and tested the spark as instructed above. I got a small orange spark on both sides, it was certainly not blue or bright. Does this spark color / intensity depend on the charge in the battery? Yesterday I had the battery on a charger for a few hours and it started up. Today I did not charge it and it did not start. The battery has 13 volts. The secondary resistance reading for both coils is over the spec. (16.6 when it should not be above 16 K ohm) Does this mean that the coils are giving the electrical current too much resistance and not enough energy is being delivered to make a big fat blue spark at the plug?

Could this weak orange spark be the reason my plugs were getting dirty? My carbs may have been clean and operating correctly but the spark was not strong enough? Does the Vulcan 500 of the 1990's use the same coils as the 454?

thanks in advance


brendan

[eaglerider]

Even tho the battery shows 13 volts...is that with the engine off? If so, get some help, have someone crank the engine and wee what the voltage is. It is possible that you have a battery with a bad cell, and when you try to start the bike, the battery just does not have enough juice to work the starter and the ignition. Yes, the Vulcan coils are the same....however, I do not think there is any problem with your coils, but I have been wrong before.

[Blaine]

I agree.I think your battery is toast.

[Deleted]

here is my update:
I got the bike running, it idles at 12000-1300, voltage going to battery is 13.8 volts when idling. I checked the fuel level in the carbs and it was too high. This caused too much fuel to be sucked into the engine. This might explain how it ran better without the filters, extra air would have mixed with too much fuel giving an acceptable mix. It sounds a little rough as I rev it up, but it doesnt cut out.
Do you guys use high octane super gas? What is the problem with alcohol in gasoline? Thanks for the advice.