Symptoms of a bad coil, or CDI ??

Bill Hilly · 08-15-2023, 02:59 PM

I decided to go to my farm and mow today, just like many other times. I took my TBR7, which is now showing around 4,300 on the odometer. I left the house, went a few milk on the main roads to town, through town, and back out of town up RT33 East. It's a pretty long climb coming out of Ripley, but it once I was about 2 miles out of Ripley, and the to had already flattened out some, my bike started sputtering, like almost out of gas. I happened to be getting ready to pass a store that sells gas, so I got a tank. It only took 1.75 gallon though, I left the gas station heading towards the farm, and climbed one more hill, and it started sputtering a little, but wasn't constant. I decided to keep on heading to the farm, thinking I would drain the carb when I got there, but it kept getting worse, and by the time I got to the farm, it was pretty bad. The grass wasn't too bad , so I figured I would work on the bike to get home. I drained the carb, and messed just a little with the idle mix, but the bike idled just fine. I may have had the bike shut off for 10, or 15 minutes, but not long. I headed home, and the bike didn't seem bad, on the short stretch of gravel road, but once I hit blacktop, I could tell it was still doing it. It seemed like I could run in the highest gear possible, and keep my RPM in the lower mid range, and the bike ran alright, and had normal torque in that RPM range, but just a little bit more rpm, and sputtering would happen. It wasn't backfireing, just sputtering,and so I went slow roads home. It acts like bad carb trouble all of a sudden , but I don't see how that would have happened so suddenly on a well tuned carb. It is a Nibbi PE28FL, and I honestly can't remember if I have that plastic baffle thingy in the fuel bowl, or not, but when I opened the drain in the carb, I got good flow. I'm thinking it may be coil, or CDI, What do you all think,? I probably will order a Nibbi coil either way, but I have heard both good,and bad on the aftermarket "Amazon" CDI boxes. Any way to tell, which piece is bad? Thanks

Mudflap · 08-15-2023, 04:18 PM

First have a look at the spark plug and also make sure the sparkplug cap is screwed into the wire properly. How is the color. Rich, lean, normal? Engine kill switch fully in the on position?

**JerryHawk250** · 08-15-2023, 04:34 PM

Check all the electrical connectors. I had a pin back out on my Hawk once. It was on one of the connectors near the battery. I found it by accident while checking them.

Bill Hilly · 08-15-2023, 06:08 PM

http://

rare smileys

Quote:

Originally Posted by JerryHawk250

Check all the electrical connectors. I had a pin back out on my Hawk once. It was on one of the connectors near the battery. I found it by accident while checking them.

I took the carb off, and inspected everything. I don't have the baffle in the bowl, and took it down the road a little bit. , I was wondering if it would still act up after cooling down, and it started acting up as soon as I ho
Hit the road.http://

rare smileys. I could not find any bad connection pins. I did have the tank off not long ago putting a throttle cable on it, but I removed the tank, and made sure that no wires were pinched. I noticed that my coil has some dried mud on it, but I wasn't in any mud today. Is the black thing with fins the CDI?.
My spark plug looks like it should, but the gap was just a hair wide. I set them a .7mm, and it was a little wide. I regapped it to .7 mm, but don't want to put the tank, and seat back on to try it, because I can't imagine it going from runs good to chugging all of a sudden if it was the plug gap.

XLsior · 08-15-2023, 06:20 PM

Black thing with fins is the regulator/rectifier.

If you follow the black/yellow wire coming from the coil it will go to the CDI unit.

Bill Hilly · 08-15-2023, 09:03 PM

I will also mention that the coil looks like it has some crusty yellow looking stuff up around were there is a ground wire. I don't know if it's old grease, or something else. Do these symptoms seem like it's probably the coil, or CDI ? Does anyone have a link to the proper CDI box? I think I know what coil most get, the $17-$18 yellow Nibbi, but the also have a black one with a boot for around $11-$12. Is there any difference,?

XLsior · 08-15-2023, 09:13 PM

Find the CDI unit and unplug it so you can identify the plug configuration. typically 2 plugs though plug type can be different. (round) or [square] with a 4pin and 2 pin arrangement.

The rectifiers and coils for these china bikes are all a much of muchness and you can generally find complete coil/rectifier/CDI/plug kits listed for a generic 250cc dirt bike search.

Bill Hilly · 08-15-2023, 09:16 PM

I hav. I must have accidentally posted this. Sorry.

Bill Hilly · 08-15-2023, 09:20 PM

I have been look at some post on the Facebook TBR7 sight, and sometimes see the mention of spark plug boots having a resistor in them. Is that something that could cause my issue? I have seen them kits that come with coil, rectifier, and a CDI box, but wasn't sure if the quality.

krat · 08-15-2023, 09:39 PM

You have water in your gas.

And just because you use "alcohol free" does not mean you don't have water in your gas. Water can be present in any blend at the gas station for the same reason it develops in our individual tanks, condensation.

Where I live we are having 90+ degree days and 50 degree nights. That is all it takes.

Drain it at the petcock and check.

Bill Hilly · 08-15-2023, 09:44 PM

It kinda acts like it could be water in the gas, but I ride them very frequently, and it starts up just fine. Would it run ok at low RPM if there was water in the gas?

**JerryHawk250** · 08-16-2023, 08:04 AM

Remove the coil and clean up where the ground attaches. The coil needs a good ground. if that doesn't work, You could buy a replacement coil to rule out a bad coil. I've only had one coil get weak. It won't hurt to have a spare coil. I replaced it with a coil on plug and eliminated having a coil wire.

Bill Hilly · 08-16-2023, 10:33 AM

Thanks everyone. I let the bike sit overnight, and this morning, I removed the coil, and scratched through the paint a little on the frame around the coil bolts. I unplugged my CDI box to count the pins one connection has 2 prongs, and the other has 4. I unhooked the wire from the little inductive tachometer, and I gently put the tank back on so as not to disturb the gas anymore than necessary. I then drained a little gas out of the tank in the reserve position, thinking that any water would be in the bottom of the tank. I should have caught some to look at it, but I just let a little run into the gravel. I went down the road on a fairly fast blacktop road, and it was doing good. I hit over 55 on a straight stretch, and since it was running good, I hit Rt33, which is a faster road, and has a fairly long hill on that section, which the bike climbed good, and I took that road back to were I turn back to go home on the road, I normally take going to town. I probably went 6 miles or so total. It's cooler this morning than it was yesterday afternoon, and the bike wouldn't have gotten as hot as it did climbing the bigger, longer hills coming out of Ripley yesterday, especially considering that I had also been at couple stop lights briefly, before leaving town, but if it does start acting up again, I think it will almost have to be ignition related. I think I will go ahead, and ordered a coil, and CDI , and maybe 2 each, and get the Hawk a set. Thank everyone.

Bill Hilly · 08-16-2023, 01:50 PM

I went for a much longer ride while ago, and it ran great, and even though the day is cooler than yesterday, I would think that if it was going to act up, it would have. I ordered a coil, and a CDI for the TBR7, and planned on ordering the same for the Hawk, but I noticed that someone,who , by chance had ordered one for a TBR7, and one for a Hawk,reviewed the CDI, and stated that it's connections fit the TBR7, but not the Hawk, stating that the Hawk has more rounded connectors. I then noticed that some of the Blue "Racing" CDI 6 pin boxes do have rounded connectors. Do all, or any of the Hawks really need the CDI with the rounded connectors?, or is it more year specific, or just potlucks? I got a little tight, and ordered a red one to save a buck. LOL. I bought this coil over the yellow for the same reason. Would I be better off to cancel the coil, and get the bigger yellow one?
https://www.amazon.com/gp/aw/d/B07TD...b_b_prod_image
https://www.amazon.com/gp/aw/d/B01F6...b_b_prod_image

08-15-2023, 02:59 PM	#1
Bill Hilly Join Date: Feb 2021 Posts: 947	Symptoms of a bad coil, or CDI ?? I decided to go to my farm and mow today, just like many other times. I took my TBR7, which is now showing around 4,300 on the odometer. I left the house, went a few milk on the main roads to town, through town, and back out of town up RT33 East. It's a pretty long climb coming out of Ripley, but it once I was about 2 miles out of Ripley, and the to had already flattened out some, my bike started sputtering, like almost out of gas. I happened to be getting ready to pass a store that sells gas, so I got a tank. It only took 1.75 gallon though, I left the gas station heading towards the farm, and climbed one more hill, and it started sputtering a little, but wasn't constant. I decided to keep on heading to the farm, thinking I would drain the carb when I got there, but it kept getting worse, and by the time I got to the farm, it was pretty bad. The grass wasn't too bad , so I figured I would work on the bike to get home. I drained the carb, and messed just a little with the idle mix, but the bike idled just fine. I may have had the bike shut off for 10, or 15 minutes, but not long. I headed home, and the bike didn't seem bad, on the short stretch of gravel road, but once I hit blacktop, I could tell it was still doing it. It seemed like I could run in the highest gear possible, and keep my RPM in the lower mid range, and the bike ran alright, and had normal torque in that RPM range, but just a little bit more rpm, and sputtering would happen. It wasn't backfireing, just sputtering,and so I went slow roads home. It acts like bad carb trouble all of a sudden , but I don't see how that would have happened so suddenly on a well tuned carb. It is a Nibbi PE28FL, and I honestly can't remember if I have that plastic baffle thingy in the fuel bowl, or not, but when I opened the drain in the carb, I got good flow. I'm thinking it may be coil, or CDI, What do you all think,? I probably will order a Nibbi coil either way, but I have heard both good,and bad on the aftermarket "Amazon" CDI boxes. Any way to tell, which piece is bad? Thanks
	0

08-15-2023, 04:34 PM	#3
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,571	Check all the electrical connectors. I had a pin back out on my Hawk once. It was on one of the connectors near the battery. I found it by accident while checking them. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	1

08-15-2023, 09:16 PM	#8
Bill Hilly Join Date: Feb 2021 Posts: 947	I hav. I must have accidentally posted this. Sorry. Last edited by Bill Hilly; 08-15-2023 at 09:23 PM. Reason: Mistake. Please remove
	0

08-15-2023, 09:39 PM	#10
krat Join Date: Nov 2019 Location: KY Posts: 263	You have water in your gas. And just because you use "alcohol free" does not mean you don't have water in your gas. Water can be present in any blend at the gas station for the same reason it develops in our individual tanks, condensation. Where I live we are having 90+ degree days and 50 degree nights. That is all it takes. Drain it at the petcock and check. __________________ %90 of the Chinese motorbikes ever made are still on the road. The other %10 made it back home.
	1

08-16-2023, 08:04 AM	#12
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,571	Remove the coil and clean up where the ground attaches. The coil needs a good ground. if that doesn't work, You could buy a replacement coil to rule out a bad coil. I've only had one coil get weak. It won't hurt to have a spare coil. I replaced it with a coil on plug and eliminated having a coil wire. Attached Thumbnails __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	1

08-15-2023, 04:18 PM	#2
Mudflap Join Date: Sep 2014 Posts: 1,876	First have a look at the spark plug and also make sure the sparkplug cap is screwed into the wire properly. How is the color. Rich, lean, normal? Engine kill switch fully in the on position?
	1

08-15-2023, 06:20 PM	#5
XLsior Join Date: Aug 2020 Location: Australia Posts: 1,298	Black thing with fins is the regulator/rectifier. If you follow the black/yellow wire coming from the coil it will go to the CDI unit.
	1

08-15-2023, 09:03 PM	#6
Bill Hilly Join Date: Feb 2021 Posts: 947	I will also mention that the coil looks like it has some crusty yellow looking stuff up around were there is a ground wire. I don't know if it's old grease, or something else. Do these symptoms seem like it's probably the coil, or CDI ? Does anyone have a link to the proper CDI box? I think I know what coil most get, the $17-$18 yellow Nibbi, but the also have a black one with a boot for around $11-$12. Is there any difference,?
	0

08-15-2023, 09:13 PM	#7
XLsior Join Date: Aug 2020 Location: Australia Posts: 1,298	Find the CDI unit and unplug it so you can identify the plug configuration. typically 2 plugs though plug type can be different. (round) or [square] with a 4pin and 2 pin arrangement. The rectifiers and coils for these china bikes are all a much of muchness and you can generally find complete coil/rectifier/CDI/plug kits listed for a generic 250cc dirt bike search.
	1

08-15-2023, 09:20 PM	#9
Bill Hilly Join Date: Feb 2021 Posts: 947	I have been look at some post on the Facebook TBR7 sight, and sometimes see the mention of spark plug boots having a resistor in them. Is that something that could cause my issue? I have seen them kits that come with coil, rectifier, and a CDI box, but wasn't sure if the quality.
	0

08-15-2023, 09:44 PM	#11
Bill Hilly Join Date: Feb 2021 Posts: 947	It kinda acts like it could be water in the gas, but I ride them very frequently, and it starts up just fine. Would it run ok at low RPM if there was water in the gas?
	0

08-16-2023, 10:33 AM	#13
Bill Hilly Join Date: Feb 2021 Posts: 947	Thanks everyone. I let the bike sit overnight, and this morning, I removed the coil, and scratched through the paint a little on the frame around the coil bolts. I unplugged my CDI box to count the pins one connection has 2 prongs, and the other has 4. I unhooked the wire from the little inductive tachometer, and I gently put the tank back on so as not to disturb the gas anymore than necessary. I then drained a little gas out of the tank in the reserve position, thinking that any water would be in the bottom of the tank. I should have caught some to look at it, but I just let a little run into the gravel. I went down the road on a fairly fast blacktop road, and it was doing good. I hit over 55 on a straight stretch, and since it was running good, I hit Rt33, which is a faster road, and has a fairly long hill on that section, which the bike climbed good, and I took that road back to were I turn back to go home on the road, I normally take going to town. I probably went 6 miles or so total. It's cooler this morning than it was yesterday afternoon, and the bike wouldn't have gotten as hot as it did climbing the bigger, longer hills coming out of Ripley yesterday, especially considering that I had also been at couple stop lights briefly, before leaving town, but if it does start acting up again, I think it will almost have to be ignition related. I think I will go ahead, and ordered a coil, and CDI , and maybe 2 each, and get the Hawk a set. Thank everyone. Last edited by Bill Hilly; 08-16-2023 at 11:31 AM.
	1

08-16-2023, 01:50 PM	#14
Bill Hilly Join Date: Feb 2021 Posts: 947	I went for a much longer ride while ago, and it ran great, and even though the day is cooler than yesterday, I would think that if it was going to act up, it would have. I ordered a coil, and a CDI for the TBR7, and planned on ordering the same for the Hawk, but I noticed that someone,who , by chance had ordered one for a TBR7, and one for a Hawk,reviewed the CDI, and stated that it's connections fit the TBR7, but not the Hawk, stating that the Hawk has more rounded connectors. I then noticed that some of the Blue "Racing" CDI 6 pin boxes do have rounded connectors. Do all, or any of the Hawks really need the CDI with the rounded connectors?, or is it more year specific, or just potlucks? I got a little tight, and ordered a red one to save a buck. LOL. I bought this coil over the yellow for the same reason. Would I be better off to cancel the coil, and get the bigger yellow one? https://www.amazon.com/gp/aw/d/B07TD...b_b_prod_image https://www.amazon.com/gp/aw/d/B01F6...b_b_prod_image
	0