Bought a new CDI box....How can I confirm if it's AC or DC?

98 SNAKE EATER · 03-04-2023, 12:30 PM

Ordered a new DC CDI box and just want to confirm that it is in fact a DC unit before I start wiring

How do I verify which one I have?

Thumper · 03-04-2023, 02:15 PM

Where is the listing from where you purchased it? Can I see it? Maybe there is a clue there. Based on the narrow format, it appears to be an AC CDI unit (~1.5"). The DC kind are more like 2" wide.

It will either work or not. I do not think it can get damaged in a few minutes of test starting (or not starting!).

FYI- a 5 pin connector is not what I have seen. Most have a 4 pin connector and another 2 pin connector, sometimes can be one connector on the bike, but 6 pins total (not all necessarily are used).

98 SNAKE EATER · 03-04-2023, 04:38 PM

Quote:

Originally Posted by Thumper

Where is the listing from where you purchased it? Can I see it? Maybe there is a clue there. Based on the narrow format, it appears to be an AC CDI unit (~1.5"). The DC kind are more like 2" wide.

It will either work or not. I do not think it can get damaged in a few minutes of test starting (or not starting!).

FYI- a 5 pin connector is not what I have seen. Most have a 4 pin connector and another 2 pin connector, sometimes can be one connector on the bike, but 6 pins total (not all necessarily are used).

Here's a link to what I ordered on Amazon:

https://www.amazon.com/dp/B0B4QVL4C6...roduct_details

Wired it up today using the same diagram I made and I get plenty of spark when cranking over either with the starter motor or kick lever

Still no start with carb spray though

Even when I spray it down into the cylinder, the best I get is a few flame pops out of the carb as if the timing is way off

Would connecting an AC CDI Box throw the spark timing off or will it simply not spark at all?

On a sidenote, the spark plug they sent was wrong (way too small)

98 SNAKE EATER · 03-04-2023, 05:35 PM

Short video

98 SNAKE EATER · 03-04-2023, 05:37 PM

My quick and dirty wiring

Mudflap · 03-04-2023, 07:35 PM

I believe there is a difference between the CDIs on the GY6 engine vs the CG engine. Could be the trigger coil and magnet are in a different place, a different angle to TDC, so the spark is timed wrong. Just a guess.

Thumper · 03-04-2023, 09:09 PM

You already mentioned good compression a while back. I have a hard time believing that the spark you had BEFORE installing the new CDI unit was any problem, and I also don't thing the timing is different for a GY versus Zongshen 229cc engine. This is based on experience...I installed a GY 50, 100, 125cc variable CDI unit on my Templar, and it is fine.

You know what they say... if you have compression, spark and fueling are the all you need.

Have you checked the valve clearances? Otherwise, I say carb.
That is a pushrod engine, so
Intake should have at least 0.002" (0.002"-0.004"), and exhaust at least 0.003" (0.003"-0.006").
It should at least start if gaps are 0.001". They just expand when the engine heats up and may not close all the way. You can see the Timing mark in the small port on top of the stator housing (T for TDC).

FYI, here is the description for the adjustable AC CDI unit I got for my ZongShen 172FMM-3A (249cc):

"Naraku Racing AC CDI with adjustable timing for customized tuning on 50 to 150cc GY6 engine based vehicles. The timing adjustment screw is set in the middle from the factory and has approximately 12 to 13 turns in either direction to advance or retard the timing. The screw clicks into place at each setting. Please note: This is only compatible with AC charging systems. Please confirm plug connection is correct for your vehicle. Please see our Warranty & Returns Policy."

I see no issue with compatibility for AC based CDI between GY6 and ZS engines. Obviously, you have spark. Timing isn't an issue.

Mudflap · 03-04-2023, 10:49 PM

You can always check the timing with a timing light.

clash 168cc · 03-04-2023, 11:41 PM

Before you do anything else take off the valve cover and check your valve timing gaps. Check your timing marks at top dead center. It should be trying to start now. The DC CDI is usually the larger one about 3" long according to You Tube videos. AC CDI should be small and light. The red wire to the 2 prong plug should have battery DC voltage (hot) when the key is turned on. The AC CDI only when it's cranking or running. Compare to your old one. I doubt it would spark if it was the wrong one. Check compression after you do the valves.

98 SNAKE EATER · 03-05-2023, 01:36 PM

OK, popped the cover this morning and the lash was a bit too tight.

Loosened them up a bit (no gauge on hand, so just gave it a little wiggle) and did another compression check (again, no gauge on hand, so had to finger it)

Put the fuse back in for the CDI box, gave the cylinder a little squirt, cranked her over, but again, nothing....

Checked the spark again and noticed it was a little weaker than yesterday, so I closed the gap up a bit.

This time around, I got a good couple of loud bangs, but when I tried spraying some more, the starter began struggling (battery getting weak)

Wifey has plans for me, so I packed it up for the day.

Got a new plug coming and plan on charging the battery and soaking the carb down.

It actaully looks surprisingly clean

clash 168cc · 03-05-2023, 03:11 PM

You need to use a feeler gauge and spark gap checker. They are not optional .Not where you should wing it. If you only get popping after that, could remotely be a sheared crank shaft key. Happened to me once on a boat motor. puts the timing totally off. Or your valves are leaking/corroded possibly. Take off the head and check gasket and valves.

bogieboy · 03-05-2023, 03:30 PM

Whats the history on this motor? I see a lot of water damage/corrosion on that carb.... if water got into the engine, i would just about put money on the rings being stuck in the piston, which wil do exactly what you are describing...and thats from persomal experience, my shineray came to me with frozen rings from water ingestion, only made 60psi compression. Would pop and bang but not ever start... slapped a new piston and rings in, hran a hone thru the bore and instantly had 170psi comptession and it fired right up....

Thumper · 03-05-2023, 06:25 PM

You need to clean that carb bigtime!

For any barn find, used garage find not running for a few years this is the first stop. I think if you clean the jets, float bowl valve, blow out hidden pilot channel and choke channel it will start.

I just experienced an apparent float bowl valve blockage on a nearly new motorcycle. Runs great for a minute, and craps out. Let is sit, and runs for another couple minutes. AAArrrgghh!!!

Guess who is taking the carb off again.

98 SNAKE EATER · 03-06-2023, 01:56 PM

Quote:

Originally Posted by clash 168cc

You need to use a feeler gauge and spark gap checker. They are not optional .Not where you should wing it. If you only get popping after that, could remotely be a sheared crank shaft key. Happened to me once on a boat motor. puts the timing totally off. Or your valves are leaking/corroded possibly. Take off the head and check gasket and valves.

It could possibly be a sheared key as the motor was locked up when I got it

I managed to free it with some Kroil and a couple of downhill clutch pops in gear

I'll throw a timing light on it when I get a chance

Quote:

Originally Posted by bogieboy

Whats the history on this motor? I see a lot of water damage/corrosion on that carb.... if water got into the engine, i would just about put money on the rings being stuck in the piston, which wil do exactly what you are describing...and thats from persomal experience, my shineray came to me with frozen rings from water ingestion, only made 60psi compression. Would pop and bang but not ever start... slapped a new piston and rings in, hran a hone thru the bore and instantly had 170psi comptession and it fired right up....

According to the PO, he was riding it when the wiring harness near the headlight started to smoke and it shut down.

Been sitting eversince under a tarp without an air cleaner installed (about ~2 years according to inspection sticker)

I'll pickup a compression and leak down tester from my shop when I get a chance this week and see what the numbers are.

Quote:

Originally Posted by Thumper

You need to clean that carb bigtime!

For any barn find, used garage find not running for a few years this is the first stop. I think if you clean the jets, float bowl valve, blow out hidden pilot channel and choke channel it will start.

I just experienced an apparent float bowl valve blockage on a nearly new motorcycle. Runs great for a minute, and craps out. Let is sit, and runs for another couple minutes. AAArrrgghh!!!

Guess who is taking the carb off again.

I have it all soaking as I type, although I've seen far worse (I've had to take a chisel to the gook in my boat carbs lol)

That being said, even without a carb, I should get more than just a few pops with spray directly into the cylinder, which is why I'm thinking it may be out of time (either due to the crank key or if the wrong AC ignition box somehow makes a timing difference)

Quote:

Originally Posted by jeffrey

I found a wireing diagram for your bike at www.clevelandcyclewerks.com/gas-parts-manuals I thought it might help you out.

Thanks

I've actually had it for some time, but the wiring doesn't really go into much detail with the CDI box

bogieboy · 03-06-2023, 11:42 PM

I would bet that the compression tester will tell us all we need to know... LOL if it was locked, and you got it free, i bet the rings arent sealing very well, if at all... add to that, if the valves were too tight, the valves and or seats may be birnt a bit, you may benefit from pulling the head to inspect the bore and piston top, check and lap the vlaves, and reset the valve lash once back together...

03-04-2023, 12:30 PM	#1
98 SNAKE EATER Join Date: Feb 2023 Location: Southampton, NY Posts: 75	Bought a new CDI box....How can I confirm if it's AC or DC? Ordered a new DC CDI box and just want to confirm that it is in fact a DC unit before I start wiring How do I verify which one I have? Attached Thumbnails
	0

03-04-2023, 02:15 PM	#2
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,783	Where is the listing from where you purchased it? Can I see it? Maybe there is a clue there. Based on the narrow format, it appears to be an AC CDI unit (~1.5"). The DC kind are more like 2" wide. It will either work or not. I do not think it can get damaged in a few minutes of test starting (or not starting!). FYI- a 5 pin connector is not what I have seen. Most have a 4 pin connector and another 2 pin connector, sometimes can be one connector on the bike, but 6 pins total (not all necessarily are used). __________________ No matter where you go, there you are
	0

03-04-2023, 09:09 PM	#7
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,783	You already mentioned good compression a while back. I have a hard time believing that the spark you had BEFORE installing the new CDI unit was any problem, and I also don't thing the timing is different for a GY versus Zongshen 229cc engine. This is based on experience...I installed a GY 50, 100, 125cc variable CDI unit on my Templar, and it is fine. You know what they say... if you have compression, spark and fueling are the all you need. Have you checked the valve clearances? Otherwise, I say carb. That is a pushrod engine, so Intake should have at least 0.002" (0.002"-0.004"), and exhaust at least 0.003" (0.003"-0.006"). It should at least start if gaps are 0.001". They just expand when the engine heats up and may not close all the way. You can see the Timing mark in the small port on top of the stator housing (T for TDC). FYI, here is the description for the adjustable AC CDI unit I got for my ZongShen 172FMM-3A (249cc): "Naraku Racing AC CDI with adjustable timing for customized tuning on 50 to 150cc GY6 engine based vehicles. The timing adjustment screw is set in the middle from the factory and has approximately 12 to 13 turns in either direction to advance or retard the timing. The screw clicks into place at each setting. Please note: This is only compatible with AC charging systems. Please confirm plug connection is correct for your vehicle. Please see our Warranty & Returns Policy." I see no issue with compatibility for AC based CDI between GY6 and ZS engines. Obviously, you have spark. Timing isn't an issue. __________________ No matter where you go, there you are Last edited by Thumper; 03-05-2023 at 08:24 AM.
	1

03-05-2023, 06:25 PM	#13
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,783	You need to clean that carb bigtime! For any barn find, used garage find not running for a few years this is the first stop. I think if you clean the jets, float bowl valve, blow out hidden pilot channel and choke channel it will start. I just experienced an apparent float bowl valve blockage on a nearly new motorcycle. Runs great for a minute, and craps out. Let is sit, and runs for another couple minutes. AAArrrgghh!!! Guess who is taking the carb off again. __________________ No matter where you go, there you are
	0

03-04-2023, 05:35 PM	#4
98 SNAKE EATER Join Date: Feb 2023 Location: Southampton, NY Posts: 75	Short video
	0

03-04-2023, 05:37 PM	#5
98 SNAKE EATER Join Date: Feb 2023 Location: Southampton, NY Posts: 75	My quick and dirty wiring
	0

03-04-2023, 07:35 PM	#6
Mudflap Join Date: Sep 2014 Posts: 1,933	I believe there is a difference between the CDIs on the GY6 engine vs the CG engine. Could be the trigger coil and magnet are in a different place, a different angle to TDC, so the spark is timed wrong. Just a guess.
	0

03-04-2023, 10:49 PM	#8
Mudflap Join Date: Sep 2014 Posts: 1,933	You can always check the timing with a timing light.
	0

03-04-2023, 11:41 PM	#9
clash 168cc Join Date: Jul 2022 Posts: 94	Before you do anything else take off the valve cover and check your valve timing gaps. Check your timing marks at top dead center. It should be trying to start now. The DC CDI is usually the larger one about 3" long according to You Tube videos. AC CDI should be small and light. The red wire to the 2 prong plug should have battery DC voltage (hot) when the key is turned on. The AC CDI only when it's cranking or running. Compare to your old one. I doubt it would spark if it was the wrong one. Check compression after you do the valves.
	0

03-05-2023, 01:36 PM	#10
98 SNAKE EATER Join Date: Feb 2023 Location: Southampton, NY Posts: 75	OK, popped the cover this morning and the lash was a bit too tight. Loosened them up a bit (no gauge on hand, so just gave it a little wiggle) and did another compression check (again, no gauge on hand, so had to finger it) Put the fuse back in for the CDI box, gave the cylinder a little squirt, cranked her over, but again, nothing.... Checked the spark again and noticed it was a little weaker than yesterday, so I closed the gap up a bit. This time around, I got a good couple of loud bangs, but when I tried spraying some more, the starter began struggling (battery getting weak) Wifey has plans for me, so I packed it up for the day. Got a new plug coming and plan on charging the battery and soaking the carb down. It actaully looks surprisingly clean
	0

03-05-2023, 03:11 PM	#11
clash 168cc Join Date: Jul 2022 Posts: 94	You need to use a feeler gauge and spark gap checker. They are not optional .Not where you should wing it. If you only get popping after that, could remotely be a sheared crank shaft key. Happened to me once on a boat motor. puts the timing totally off. Or your valves are leaking/corroded possibly. Take off the head and check gasket and valves.
	0

03-05-2023, 03:30 PM	#12
bogieboy Join Date: May 2013 Location: finger lakes NY Posts: 2,062	Whats the history on this motor? I see a lot of water damage/corrosion on that carb.... if water got into the engine, i would just about put money on the rings being stuck in the piston, which wil do exactly what you are describing...and thats from persomal experience, my shineray came to me with frozen rings from water ingestion, only made 60psi compression. Would pop and bang but not ever start... slapped a new piston and rings in, hran a hone thru the bore and instantly had 170psi comptession and it fired right up....
	0

03-06-2023, 11:42 PM	#15
bogieboy Join Date: May 2013 Location: finger lakes NY Posts: 2,062	I would bet that the compression tester will tell us all we need to know... LOL if it was locked, and you got it free, i bet the rings arent sealing very well, if at all... add to that, if the valves were too tight, the valves and or seats may be birnt a bit, you may benefit from pulling the head to inspect the bore and piston top, check and lap the vlaves, and reset the valve lash once back together...
	0