Nc35 starting issues- never ending issues...

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Skim325
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Re: Nc35 starting issues- never ending issues...

Post by Skim325 » Mon Sep 14, 2020 12:26 pm

Thanks. I’m hoping this is the root cause of the issue as well. Thank you for the tips and crossing my fingers!


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Suzuki416
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Re: Nc35 starting issues- never ending issues...

Post by Suzuki416 » Mon Sep 14, 2020 11:27 pm

good find.

I think that Rick Oliver also sells a uprated Earthing kit...

Go through the wiring & if its damaged replace it. Then pull the cover off the stator. You WILL need a replacement cover gasket so order that first.

What you are looking for is if your stator is damaged which can happen when you have those melted cables.

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Re: Nc35 starting issues- never ending issues...

Post by Skim325 » Tue Sep 15, 2020 8:54 am

Quick question. Can someone tell me where the front carbs gets grounded? I am running a continuity test by touching the negative lead to the front carb (the cover that holds the spark plugs) and it still is showing a lack of continuity. Where the rear carb cover gives readings in line with the rest of the bike.

I replaced the connectors for the three yellow wires coming out of the stator so that’s nice. Unfortunately, Aside from that I found another point of failure as it looks like a connector was melted at the rectifier. Picture below.

Image


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Re: Nc35 starting issues- never ending issues...

Post by Skim325 » Tue Sep 15, 2020 9:54 am

Suzuki416 wrote:good find.

What you are looking for is if your stator is damaged which can happen when you have those melted cables.
Thanks for that suggestion. I’ll do that. Question is, what does damage to a stator look like? What would I be looking for when I inspect the stator? Would it be visibly brunt out, black marks or some sort of discoloration?




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tazbert
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Re: Nc35 starting issues- never ending issues...

Post by tazbert » Tue Sep 15, 2020 10:19 am

Skim325 wrote:
Tue Sep 15, 2020 8:54 am
Quick question. Can someone tell me where the front carbs gets grounded? I am running a continuity test by touching the negative lead to the front carb (the cover that holds the spark plugs) and it still is showing a lack of continuity. Where the rear carb cover gives readings in line with the rest of the bike.
can I just put a note here? If I understand correctly you are trying to get an earth to the 'cover that holds the spark plugs'? That would be the rocker cover, over the camshafts. The spark plugs don't actually go into that, they go directly into the cylinder head that is the block beneath the cover. The cover is isolated from the head by rubber gaskets - the rear cover shouldn't really give continuity, though a bolt may be touching somewhere. Try getting an earth lower down the engine, around the area where the head bolts to the frame.

Another test would be to swap the front and rear plugs, does the problem move?

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Re: Nc35 starting issues- never ending issues...

Post by Skim325 » Tue Sep 15, 2020 10:40 am

tazbert wrote: can I just put a note here? If I understand correctly you are trying to get an earth to the 'cover that holds the spark plugs'? That would be the rocker cover, over the camshafts. The spark plugs don't actually go into that, they go directly into the cylinder head that is the block beneath the cover. The cover is isolated from the head by rubber gaskets - the rear cover shouldn't really give continuity, though a bolt may be touching somewhere. Try getting an earth lower down the engine, around the area where the head bolts to the frame.

Another test would be to swap the front and rear plugs, does the problem move?
Ah thanks for the correction. Yes. Rocker cover. So I tested lower on the engine as well and it seems to be in line with the frame of the bike. Ok so the rocker giving not giving a proper reading is not a problem? Sounds like I was chasing a red herring this afternoon.

I’ll try swapping the plugs to see if the problem follows. The spark plugs are all new, as I replaced them not too long ago, but I’ll try anyway.
Suzuki416 wrote:check your earth on the front carbs
Ok so where should I have been testing if not the rocker cover?



In any case, it looks like I may need to first test that rectifier. I believed there is testing procedures in the Haynes manual, so I’ll need to test it to see if it’s still even good or not.
Plus I’ll need to patch up that cable in the picture that has a bit of exposed wiring. But replacement caps for those things as well
And finally, I should look in to checking the stator for any signs of damage.




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tazbert
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Re: Nc35 starting issues- never ending issues...

Post by tazbert » Tue Sep 15, 2020 11:20 am

Another thought (my bike is an NC30 so it may be different). the stator wires come up the left side of the engine, and that area is also where the coil for the front two spark plugs lives. Is any of that damaged wiring connected to the coil? It is difficult to get context from the photo, but that looks to be the correct area (I think!)

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Re: Nc35 starting issues- never ending issues...

Post by magg » Tue Sep 15, 2020 12:32 pm

Was the bike running on all cylinders before you did "the minor carb rebuild"?

Why are you looking for the ground on the front carbies, there is none.

The alternator connector damage is caused by deteriorated contacts. Fix all the connections, including the rect/reg, and then check the charging system performance, around 14 volts at the battery at 5000rpm is a pass. The front ignition coil is located in the same area as the damaged alternator/loom connector, is it not. Has the damaged alternator connector also damaged the loom and perhaps the leads to the front ignition coil.

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Re: Nc35 starting issues- never ending issues...

Post by Suzuki416 » Tue Sep 15, 2020 3:25 pm

The 'Common' earth for the front coils is on the bottom right of the engine near the starter. Think its a 10mm bolt.

if you have the manual i think it shows the stator & how it should look.

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Re: Nc35 starting issues- never ending issues...

Post by Skim325 » Sat Sep 19, 2020 5:42 am

magg wrote:Was the bike running on all cylinders before you did "the minor carb rebuild"?

Why are you looking for the ground on the front carbies, there is none.

The alternator connector damage is caused by deteriorated contacts. Fix all the connections, including the rect/reg, and then check the charging system performance, around 14 volts at the battery at 5000rpm is a pass. The front ignition coil is located in the same area as the damaged alternator/loom connector, is it not. Has the damaged alternator connector also damaged the loom and perhaps the leads to the front ignition coil.
The bike was running poorly before I did the carb rebuild. I suspected an issue possibly with clogged jets and tried there first.

I fixed the connectors to the alternator, pulled the rectifier and checked the readings, and testing the leads showed consistent results all around.

The front ignition coil is indeed located on the same side as the damaged connectors shown in one of the pictures above, but it does not look like the connectors to the ignition coil had any damage to them visually.


Suzuki416 wrote:The 'Common' earth for the front coils is on the bottom right of the engine near the starter. Think its a 10mm bolt.

if you have the manual i think it shows the stator & how it should look.
Thanks, I’ll have to look for that.




So today I tested to rectifier, and as mentioned above, still seems to be working. Well at least, when testing the leads with a multimeter, seem to give off consistent readings when testing the leads that go to the alternator.
So now, I think I’ll fit it back to the bike and start getting readings with.the bike off, cranking, and charging as suggested by


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