Wtf is wrong with my GN250?

[investinwaffles]

OK guys,
I have an actual GN250 issue (sorry to interrupt the schenanagains). Hoping someone here might be able to help me out.


Been having a bad electrical issue with the GN. I thought it was a carb issue, but I'm positive is not a carb or fuel issue after the most recent course of events.

1. It started out being a charging system issue that I thought had to do with fuel. It would run great when the bike was cold and battery fully charged or rested, but after 15 mins of riding or idling it would start running really rough and then die. I thought it was the carb, so I redid the whole fuel system (full carb rebuild, cleaned tank, new plug, etc). The problem persisted though, but seemed to be better (meaning it would run longer and would restart after dying and I let it sit for 10 mins most of the time).

2. Then I realized that the bike wasnt charging, and replaced the rectifier. Bike was now charging great, voltage off the batter was at 14.5-14.8v when running and about 14v when idling. BUT the problem still persisted. I thought the battery might be bad, hence the high charging voltage.

3. Replaced the battery but the problem STILL persisted. I was riding it trying to warm it up to keep testing, but the bike would still run like shit after 10 mins, and want to die at dle. I blipped the throttle to keep it running, and as I closed he throttle body it backfired pretty loud and then died. I got it to restart for a second, but it died and refused to start after that. Let it cool off and topped off the battery, but im getting no spark now!!

4. Brought it home, and let it sit overnight and I'm still getting no spark. Replaced the coil with a 100% guaranteed working used coil but still no spark.


I have been through this bike with exception to the stator and the pickup coil because I dont really know what to look for in there, but I am going to pull the cover off and see what it looks like in there. The wiring I am 99% sure is good - no kickstand switch, starter is kind of bypassed, all ignition and charging wires are perfect or redone where they werent, only one fuse I can see and its good.

I cant figure this out and its driving me insane
Have been taking the bus to work daily and it not only makes me miserable and feel like crap - but also wastes 2hrs of time every bloody day.

[Paul in NZ]

Hmm - thats not fun...

Just a wild guess but perhaps when the rect/reg was going down its spiked the ignition module?

[investinwaffles]

Hmm - thats not fun...

Just a wild guess but perhaps when the rect/reg was going down its spiked the ignition module?

Ignition module being the CDI? I have not checked that thoroughly either but I have the pinout from the user manual with all the resistance values. Will check it now and hope for the best (they are pretty pricy)

[bosslady]

The easiest thing to do is buy a new bike, least that's what I found...

[Paul in NZ]

Ignition module being the CDI? I have not checked that thoroughly either but I have the pinout from the user manual with all the resistance values. Will check it now and hope for the best (they are pretty pricy)

Yup - sorry but its quite likely....

Anyone here got a spare unit they can send to this poor bugger....

[Maha]

The easiest thing to do is buy a new bike, least that's what I found...

It's what I do, even when I don't need to...

[Banditbandit]

The easiest thing to do is buy a new bike, least that's what I found...

Yeah .. that's exactly what I was gong to suggest .. but first, he has to make it run so he can sell it ..

[Banditbandit]

I have been through this bike with exception to the stator and the pickup coil because I dont really know what to look for in there, but I am going to pull the cover off and see what it looks like in there. The wiring I am 99% sure is good - no kickstand switch, starter is kind of bypassed, all ignition and charging wires are perfect or redone where they werent, only one fuse I can see and its good.

I cant figure this out and its driving me insane
Have been taking the bus to work daily and it not only makes me miserable and feel like crap - but also wastes 2hrs of time every bloody day.

I was about to say it's either the stator/altenator, or the coils .. CDI unit .. I suspect the coil ... if they are faulty they can cause the engine to fart around a lot and whern they get hot they die .. when they cool down they go again .. until they get hot .. the fact that it's not running now the coil is cold could be beause the coil is really really really fucked ..

[Drew]

Hmm - thats not fun...

Just a wild guess but perhaps when the rect/reg was going down its spiked the ignition module?

I'm in full agreement here.

Initially the symptoms perfectly fit a failing coil, but if we can 100% rule that out I'd be trying to borrow a CDI for the purpose of testing...Out of a running bike of course.

I was about to say it's either the stator/altenator, or the coils .. CDI unit .. I suspect the coil ... if they are faulty they can cause the engine to fart around a lot and whern they get hot they die .. when they cool down they go again .. until they get hot .. the fact that it's not running now the coil is cold could be beause the coil is really really really fucked ..

This all sounds legit, but coils fucking out on anything that doesn't run points ignition is very rare. For you to have two buggered ones? Chances are better for winning lotto. Check it again though.



Oooooohhhh. 'Hall effect' sensors (pulse generators) can be a fickle bitch too. Eliminate the more likely coil and CDI options, then find this little bugger and test. You'll get a simple voltage reading across it's wires (or between it's one wire and ground) as the motor turns over if it's working. You'll need to look up what the value should be.

[Mom]

I'm in full agreement here.

Initially the symptoms perfectly fit a failing coil, but if we can 100% rule that out I'd be trying to borrow a CDI for the purpose of testing...Out of a running bike of course.

This all sounds legit, but coils fucking out on anything that doesn't run points ignition is very rare. For you to have two buggered ones? Chances are better for winning lotto. Check it again though.



Oooooohhhh. 'Hall effect' sensors (pulse generators) can be a fickle bitch too. Eliminate the more likely coil and CDI options, then find this little bugger and test. You'll get a simple voltage reading across it's wires (or between it's one wire and ground) as the motor turns over if it's working. You'll need to look up what the value should be.

OR...

Make sure it is well insured and push it off the nearest cliff

Poor little Ginny

[Banditbandit]

This all sounds legit, but coils fucking out on anything that doesn't run points ignition is very rare. For you to have two buggered ones? Chances are better for winning lotto. Check it again though.

Yeah .. that's why I first suggested the stator/rotar - but the description of what the bike is doing matches a dead coil ... rather than a dead alternator ...

[investinwaffles]

Yup - sorry but its quite likely....

Anyone here got a spare unit they can send to this poor bugger....

I think I can use a CDI from a GZ250 (someone correct me if thats horribly wrong). They are only $60 USD on ebay which isnt too bad.

Yeah .. that's exactly what I was gong to suggest .. but first, he has to make it run so he can sell it ..

Precisely (I have my eye on a DR650 that looks delicious and can actually do 80MPH without killing itself).

I was about to say it's either the stator/altenator, or the coils .. CDI unit .. I suspect the coil ... if they are faulty they can cause the engine to fart around a lot and whern they get hot they die .. when they cool down they go again .. until they get hot .. the fact that it's not running now the coil is cold could be beause the coil is really really really fucked ..

I replaced it with one out of a functioning bike, and I have the other one here as well. Neither are throwing spark right now and one at least has to be good (likely that both are).

I'm in full agreement here.

Initially the symptoms perfectly fit a failing coil, but if we can 100% rule that out I'd be trying to borrow a CDI for the purpose of testing...Out of a running bike of course.

This all sounds legit, but coils fucking out on anything that doesn't run points ignition is very rare. For you to have two buggered ones? Chances are better for winning lotto. Check it again though.



Oooooohhhh. 'Hall effect' sensors (pulse generators) can be a fickle bitch too. Eliminate the more likely coil and CDI options, then find this little bugger and test. You'll get a simple voltage reading across it's wires (or between it's one wire and ground) as the motor turns over if it's working. You'll need to look up what the value should be.

So I tested the CDI just now and it is almost certainly bad. I get NO continuity through ANY of the terminals and the service manual says I should see resistance on several combos on the connectors.
I am 99% sure it is bad, something should at least register and I cant find electrical fault in any of the other systems (pickup coil tests good, ignition coil tests good, stator and rectifier are good, no shorted wiring or anything else I can see thats wrong).


The best part is the only ones available in the US are $200 USD or so (Used, and built in 1984). Needless to say i cant really afford that right now.

I can get one off a 97' for $50 + shipping from the UK (probably a week till I can get it in my hands)
http://www.ebay.com/itm/SUZUKI-GN-25...4f0aad&vxp=mtr

I can get a generic looking one from China for $44, but will probably take 2+ weeks to get to me;
http://www.ebay.com/itm/Suzuki-GN-25...e29353&vxp=mtr


OR, I was wondering if anyone knew if I could use a GZ250 CDI with the GN250
GZ uses 8 pins, GN uses 6 pins but 2 of those are probably useless anyway.
http://www.ebay.com/itm/06-Suzuki-Ma...5cb67d&vxp=mtr

I could have that one in my hands on Wednesday but if it wont work it wont work I guess.

I looked at the user manual and it doesnt give indications on what each pin specifically is (just says the assigned number and wire color).
I read this random yahoo question that gave me some hope;
http://wiki.answers.com/Q/Is_any_oth...zuki_gz_250_cc


FML - This is going to take a while to sort out I think

[ducatilover]

I think I can use a CDI from a GZ250 (someone correct me if thats horribly wrong). They are only $60 USD on ebay which isnt too bad.


Precisely (I have my eye on a DR650 that looks delicious and can actually do 80MPH without killing itself).



I replaced it with one out of a functioning bike, and I have the other one here as well. Neither are throwing spark right now and one at least has to be good (likely that both are).



So I tested the CDI just now and it is almost certainly bad. I get NO continuity through ANY of the terminals and the service manual says I should see resistance on several combos on the connectors.
I am 99% sure it is bad, something should at least register and I cant find electrical fault in any of the other systems (pickup coil tests good, ignition coil tests good, stator and rectifier are good, no shorted wiring or anything else I can see thats wrong).


The best part is the only ones available in the US are $200 USD or so (Used, and built in 1984). Needless to say i cant really afford that right now.

I can get one off a 97' for $50 + shipping from the UK (probably a week till I can get it in my hands)
http://www.ebay.com/itm/SUZUKI-GN-25...4f0aad&vxp=mtr

I can get a generic looking one from China for $44, but will probably take 2+ weeks to get to me;
http://www.ebay.com/itm/Suzuki-GN-25...e29353&vxp=mtr


OR, I was wondering if anyone knew if I could use a GZ250 CDI with the GN250
GZ uses 8 pins, GN uses 6 pins but 2 of those are probably useless anyway.
http://www.ebay.com/itm/06-Suzuki-Ma...5cb67d&vxp=mtr

I could have that one in my hands on Wednesday but if it wont work it wont work I guess.

I looked at the user manual and it doesnt give indications on what each pin specifically is (just says the assigned number and wire color).
I read this random yahoo question that gave me some hope;
http://wiki.answers.com/Q/Is_any_oth...zuki_gz_250_cc


FML - This is going to take a while to sort out I think

Order one from C2345.com if you can work the site, or any other reputable taobao agent. A GZ250 one will work, TU250 and obviously the GN, I don't think early DR250 ones will work as they run a different pick up coil

[investinwaffles]

OK - new update but no progress
So I sourced a confirmed good CDI from a seller in the UK.

I hooked everything up and triple checked my wiring before test firing it with a brand new spark plug, outside of the motor but grounded to the frame.
I got spark consistently!! Which is great and exactly what im looking for. I cranked it several different times and each time I got a good strong blue spark.

Then, I turned the key off and put the gas tank back on, and hooked everything back up (including the coil to the plug that was already in the motor). Opened the petcock and filled the carb bowl (was sitting for a week so I assume it evaporated).

Turned the key but it still sounded like it was getting no spark, and obviously wasnt firing. So I pulled the plug boot off, and hooked up the new plug (grounded to the frame again), but got NO spark again!

This is so fucking frustrating


Also, the multimeter test procedure listed in the manual (Section 5-2) is NOT working for me, with either CDI.
It specifies to put the multimeter on the CDI in various configs with the + and - terminals of the multimeter on 1K ohms. My multimeter only has increments of 2xK ohms but it doesnt register on any setting with the unit unplugged - I tested the new unit before I tried to crank it and it was the same thing.

Any advice?

[Drew]

Sounds like a dodgy ignition switch or something similar to me.