Coils gone bad?

2strokedGT · Post by **2strokedGT** » Mon Oct 06, 2014 11:20 am

Looks like my GT380 is having problems. It starts on the first kick but feels like its not running on all
cylinders and getting kind of a vibrating feel on acceleration and when stopping revs will drop below 1000 and usually dies at this point.

Previous to this it was running great carbs are in synch,always started on first kick could go for an hour ride with no problems.Last time I rode it it felt like everything shut off instantly and it quit,started back up and limped back home on what seemed like only 2 cylinders.

What I have checked so far is battery which is at 12.8-13.00 volts,removed plugs and am getting spark at all 3 plugs and using LZFH non resistor caps,did a check of the coil on the female side of the coil connector and i'm getting about 6 ohms for each coil and the secondary readings only give 12k at the middle coil the other 2 coils only read .1 (Update- I read the orientation of the wire harness wrong so each coil reads about 12k for the secondary & 6 ohms for the primary)
Can I be getting spark and have bad coils? Adding to the confusion I found out I sheared off my rear left turn signal so both bullet connectors for the rear signals are disconnected currently don't know if this has anything to do with it?
Appreciate any advice may have to end the riding season early .. major bummer.

tz375 · Post by **tz375** » Mon Oct 06, 2014 12:44 pm

In general, the primary side of your coils (disconnected from the harness should be 3-6 ohms. Secondary - from primary side to plug connection should be in the 9-15k range. Check the manual to find the range for that bike.

It sounds like you are running on two and it could also be that it sucked something into one carb and blocked the fuel supply.

2strokedGT · Post by **2strokedGT** » Mon Oct 06, 2014 1:57 pm

could also be that it sucked something into one carb and blocked the fuel supply.

Good point on the fuel supply
I run fuel filters on all 3 carbs and just noticed one of the paper elements for the middle cylinder filter looks crushed and maybe blocking fuel delivery I'll try new filters next.
I run pods for the air filter so i'd have to rule out anything getting sucked into the carb.

tz375 · Post by **tz375** » Mon Oct 06, 2014 2:37 pm

When I said "sucked into a carb", I should have been more specific. I didn't mean through the air inlet. I meant via the fuel tap and fuel filters.

You mentioned fuel filters. You may want to check fuel flow through those. I have tried a few over the years and so far am nor happy with any other than the large ones on modern bikes.

And check the filters inside the fuel tap/on the top of it. If they are staring to silt up, that may be enough to restrict flow. In your case it does sound like you lost one cylinder though, so I would check all 3 plugs for color to see if one is much whiter than the others and while the plugs are out, I would do compression check on all three - just to be sure.

2strokedGT · Post by **2strokedGT** » Mon Oct 06, 2014 3:13 pm

I did rebuild the petcock within the last month with new screens and gaskets and there is a constant flow of fuel out of the 3 barbs going to each carb regardless of vacuum don't know why exactly why thats happening.
I'll have to check out the spark again and will swap some known good working fuel filters that I have but yeah just how good is a $3 fuel filter probably not that good.Was thinking the same about the compression i'll have to invest in a guage.

Cliff · Post by **Cliff** » Mon Oct 06, 2014 4:43 pm

Still running points and condensers? Could be a condenser gone bad or dirty points?

2strokedGT · Post by **2strokedGT** » Mon Oct 06, 2014 5:26 pm

Its got an Accent electronic ignition in it.

tz375 · Post by **tz375** » Mon Oct 06, 2014 5:39 pm

Just in case you were thinking of a cheap Harbor Freight compression tester - don't. I have thrown two of them away so far.

You can probably borrow one from your local auto parts store.

2strokedGT · Post by **2strokedGT** » Mon Oct 06, 2014 5:59 pm

Thanks for the info I've got a Harbor Freight floor jack that i'm about to throw out only lasted a few months will be more careful about what i buy from them.

2strokedGT · Post by **2strokedGT** » Tue Oct 07, 2014 5:22 pm

Well this is a hoot
Wired in my new reproduction turn signal that fell off and it runs like a champ now and back
to the power it had previously.The signal grounds onto the mounting plate maybee it serves another purpose for a ground on the bike?
Appreciate the help and ideas on this so glad this forum exists or i'd be lost.

Coils gone bad?

Coils gone bad?

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