Coil packs, replace one or both?

[timebombprod]

Been a while, done a lot since then but still made a newby mistake of not thinking other things could be the problem my bike doesn't run right

The question is when replacing coil packs is it okay just to replace one or is it recommended to change both at the same time?

All the rest is describing why I think it's possibly the coilpack, maybe something I say could signify it's something else but I dont know.

I thought the reason cylinder 3 wasn't operating was because its fuel level possibly not being right, and it sounded appropriate with what I was experiencing (idle jumping like a cylinder wanted to turn on after some revs) but even after getting them adjusted it still wasn't right.

Did a spark test more recently and cylinder 1 and 4 would shut the bike off when the plug cap was pulled, 2 would change tone but barely, and 3 would not do anything, still had a little suspicion of it being maybe fuel level but after pulling and checking all 4 spark plugs, 1 and 4 burn beautiful, 2 kindove burns, 3 smelled like fresh gas with barely even a sign of any spark going on, this sounds like a coilpack right?

Spark plugs have been changed before and again.

If you think that it may be something else, please let me know! Not afraid to test anything!

I cleaned the connections of the plug caps and also the wires that connect to the coilpack, lots of white stuff but it wasn't powdery, it may have been some anti corrosion stuff that's been there since it was made. I'm gonna turn it on tomorrow as its night and I dont wanna bother the people but if the cleaning makes the spark go through I'll say ASAP.


Also the thing sounds like @$$ right now it chops rough when idling and if u give it a rev it sounds like its pushing to do so, itll do it but roughly (I'm not sitting here doing constantly I just wanted to see how its react) also pops and backfires are going on, carbs are nice and clean just looked at the inside the other day.

OH, and this has been rode, I've had the idle shoot up from 1100 to almost 2000 before on a ride, the idle has always shot up after a bit of riding but usually to like 1500, and if I sit at a stop for a while eventually it goes back down to idle. that's why I had a suspicion of fuel level for so long but maybe it's the coil pack having a weak connection and coming in and out?

 

[roeme]

No, it's not necessary to replace both coils at the same time.

Measure the coils' primary and secondary resistance, for good measure (hehe), and report the numbers here.

 

[timebombprod]

Alright will do aslong as I have the tool (I probably do). Dont know if you read the whole post but I must say, the connections to the coilpack for 1 and 4 did not have nearly the amount of that white stuff as the other one, will it make a difference? I'll find out tomorrow.

 

[LAB3]

Just to check if you've eliminated all the possible problems, have you checked out the spark plug caps? Seems to be a pretty common item to go bad, they should have 5k ohm resistance.

 

[timebombprod]

Just to check if you've eliminated all the possible problems, have you checked out the spark plug caps? Seems to be a pretty common item to go bad, they should have 5k ohm resistance.

Not yet no gonna be testing stuff today, will say cylinder 3s plug cap likes to give me a buzz throughout my hand when pulled off, sign of it needing replacement or repair? Never happened with the others

 

[Brendan W]

Not yet no gonna be testing stuff today, will say cylinder 3s plug cap likes to give me a buzz throughout my hand when pulled off, sign of it needing replacement or repair? Never happened with the others

Sounds like the high voltage finds you easier to get through than the plug cap. Replace it or swap it with another and have you checked the conductor in the last few mm of the HT lead? Sometimes chopping of the tail end makes things much better.

 

[timebombprod]

Sounds like the high voltage finds you easier to get through than the plug cap. Replace it or swap it with another and have you checked the conductor in the last few mm of the HT lead? Sometimes chopping of the tail end makes things much better.

Conductor? HT lead? Sorry all new terminology to me but yes I will probably be replacing the plug cap or maybe run through it? How salvageable are they?


Edit: definently a coilpack plug, 1 2 and 4 steam like no other when sprayed with water on header, 3 let's the water sit and hangout. Sounded a tiny bit cleaner after cleaning the connections, still got backfire pops and a rough acceleration.

 

[timebombprod]

Okay... so, I turned it on today to see if the cleaning of the connections helped, just right now before I turned the bike off because of seeing white smoke the idle went from 1100, to 1500, to 2000. I checked the header pipe with water on 3 and it was in fact steaming, my bike still is over here popping and having a rough acceleration, and carb 2 now doesn't pull in air like the other 3 on the carbtune, clogged jet?

This was after the video I linked If I confused anyone, but basically the same stuff was going on except the idle going up like that, and then l header 3 steaming. White smoke may have been the cylinder finally firing and cleaning up the carbon and such atleast I hope it is, I checked the valves a while back after I first ran it and all were good so it shouldn't be because of one being too close I'd think you'd hear it hitting right now the bike sounds like some old twin or something


Most recent vid of it being on today, Sound and all.


https://youtu.be/S_OiDtKwvzs


I know you guys have been saying test the electric stuff, and i will, but I'm guessing it's not my only issue

 

[LAB3]

When we talk about HT leads it means the heavy wires that go to the spark plug caps. If you grab the spark plug cap you can pull the lead (wire) straight out of the cap. Clip off about 1/4" of that wire and reinstall it back into the spark plug cap. To test the resistance of the cap you'll need a volt meter, I'm including a link for a low priced one below. It's a good tool to have and has MANY uses besides fixing a motorcycle, keep it clean and dry and it should last a long time.

https://www.harborfreight.com/elect...ters/7-function-digital-multimeter-63759.html

 

[timebombprod]

When we talk about HT leads it means the heavy wires that go to the spark plug caps. If you grab the spark plug cap you can pull the lead (wire) straight out of the cap. Clip off about 1/4" of that wire and reinstall it back into the spark plug cap. To test the resistance of the cap you'll need a volt meter, I'm including a link for a low priced one below. It's a good tool to have and has MANY uses besides fixing a motorcycle, keep it clean and dry and it should last a long time.

https://www.harborfreight.com/elect...ters/7-function-digital-multimeter-63759.html

Cut them back and refitted and I must say even without the test I have some confidence that its gonna react better, I didnt see the wires when I first looked in the hose and not really after looking close until I clipped it back some. Still gonna test and also gonna run through carbs before its turned on because that air not coming through and its roughness does not sound right. Anyone watch the vid by chance?

 

[roeme]

You're beginning to jump all over the place, like many others before you. You need to approach this methodologically and eliminate possible issues one-by-one.

As suggested multiple times, measure resistance of primary/secondary windings of your coils, as well as spark plugs. A cheapo multimeter ("voltmeter") as linked by LAB3 will suffice.

 

[timebombprod]

I finished it this morning was a bad connection the the plugs running all 4 all the time now and the carbs were choking because of me not plugging the vacuum line on the carbs. Still getting some pops and dirtiness but I'm assuming it's from the cylinder finally being turned on because the throttle reaction is just right.

 

[LAB3]

I finished it this morning was a bad connection the the plugs running all 4 all the time now and the carbs were choking because of me not plugging the vacuum line on the carbs. Still getting some pops and dirtiness but I'm assuming it's from the cylinder finally being turned on because the throttle reaction is just right.

Your carbs where rebuilt by a respectable guy so if there's still some weirdness going on I'd give those plug caps a check, a very common item that goes bad with time.

 

[timebombprod]

Your carbs where rebuilt by a respectable guy so if there's still some weirdness going on I'd give those plug caps a check, a very common item that goes bad with time.

I know, it's also been a long time so theres no blame on the person who worked on my carbs. What I'm going to ask next is how to check and set my timing, was talking to dad and he said most of the time he had backfires and pops was because the timing was off, and hey I've never checked it. Easily revs with clutch pulled in but pops and had flat spots while in gear (maybe jetting, never tuned for the exhaust) if I roll smooth it's okay if I give gas it chops a bit. Theres also a weird electric whir going on that u barely hear unless u let off the throttle, and it also stop once the rpm goes back down to about idle.

Edit: i'm gonna see if that weird whirring sound is the tachometer cable spinning, if so I'll lubricate it and i have a PT multimeter, how do i set it up? Never used one before but I'm gonna be checking all my plug connections today and if theyre weak I'll check the wire connection (is that safe?)

 

[timebombprod]

Am I completely taking off the wire from the coilpack aswell?

If needing replacement, are NGK plug caps reputable and is the wire 7mm thick with the tubing?

 

[timebombprod]

How do I test the cap and wire setup? Am I pressing the starter button with the cap unplugged from the spark and seeing what it reads? Or am I taking it completely off and doing something else?

 

[Redman]

How do I test the cap and wire setup? Am I pressing the starter button with the cap unplugged from the spark and seeing what it reads? Or am I taking it completely off and doing something else?

Not while trying to run engine.

Twist cap off the wire.
Measure Ohms (resistance). Meter on Ohm scale. Test the meter itself by touching leads together, should read Zero. THen to test the cap, One lead into each end of the cap to make contact. SHould be about 5K (5000). As the cap goes bad it can be 10k or 20k or 50k or 100k then goes completely open infinity and readthe same as if leads are on nothing.
Replacement caps are less than 5 bucks each. Do go bad with miles and heat.
Also look to see if can see the "conductors" at the end of the wire. If suspect, cut end off about 3/8".

Yes, NGK.
THe two inside caps are different part number from the outside two. Only so the inside are longer to reach, and outside shorter so dont have knee against it.

 

[Burque73]

Am I completely taking off the wire from the coilpack aswell?

If needing replacement, are NGK plug caps reputable and is the wire 7mm thick with the tubing?

This is kind of a PITA so be careful. If you try to pull the wires out of the coil you'll find them glued in with epoxy. If you manage to get the wires out, it's difficult to clean out all the insulation from the wires and leftover glue in the hole, so the new wires will fit. Also, The little spike in the center of the hole is easy to damage if you're not careful. Gluing the new wires in needs to be done with care as not to get any adhesive on that spike too, while still using enough to get a water tight seal.

The wire I used to do this was 7mm from Auto Zone and I used a plastic weld epoxy followed by a high temp RTV to make sure it was sealed well.

 

[timebombprod]

Okay so, testing two plugs. Multimeter is set on the horseshoe setting at 20k, tested cap 2 and 3 and in getting readings of 11.2 and 11.86, now does that mean 11 thousand? If so I guess I know what it is now.

Testing by putting one feeler in the cap and other feeler on other end of cap, swapped feelers and same reading. Gonna test 1 and 4 and they've never been tooken off.


Okay so 4 is testing at 10 which is still bad but a bit lower, I tried to test one because 1 burns very well, I cant find a resistance on it? Its obviously different from plug 4 so it's some other cap but I cant get a single reading

 

[roeme]

Okay so, testing two plugs. Multimeter is set on the horseshoe setting at 20k, tested cap 2 and 3 and in getting readings of 11.2 and 11.86, now does that mean 11 thousand? If so I guess I know what it is now.

Testing by putting one feeler in the cap and other feeler on other end of cap, swapped feelers and same reading. Gonna test 1 and 4 and they've never been tooken off.


Okay so 4 is testing at 10 which is still bad but a bit lower, I tried to test one because 1 burns very well, I cant find a resistance on it? Its obviously different from plug 4 so it's some other cap but I cant get a single reading

Yep, your caps are due for replacement. As explained very well by redman, they must either read around 5k or close to zero.

It's "either" because the spark plugs themselves may have an integrated resistor as well - combining them with a resistor in the spark plug cap isn't advisable unless your ignition system is in tip top shape. Hence, you should measure the resistance of your spark plugs too to know what you have.