1999 Yamaha 350 Big Bear 2 wheel - NO SPARK

[Mech]

This is what it says in post six...

"Right now, from the side of the engine, there are 7 wires. 3 white wires go to the rectifier. The other 4 (red, green, white/red line and white/green line) go into a single plug that then go somewhere into the bigger harness all taped together.".

[Mech]

And see the drawing of the plastic plugs next to that wiring diagram you posted Gw..  those plugs aren't four pin plugs like we are dealing with here.  The manual doesn't reflect the reality of what we are working with.. 

 

[NRA4LIFE]

Here`s the mag coil specs from the manual. It`s for the fwd model, but it`s the same animal. It clearly shows 460-560 for the pick-up and 270-330 for the source coil. Also, notice the wire colors listed match his machine. Again, the stators that have a low resistance on the charge coil (Yamaha calls it a direction detection coil) are for newer machines. Those are what is called a DC CDI system. Those require a battery to work properly. The 1999 model was an actual magneto CDI system. The magneto CDI systems will NOT have voltage going to the positive side of the ignition coil until you are cranking. The DC CDI machines will have when you key on. I agree that a 500 ohm pick up coil is way above the norm, but that is what they used on that model. The Kawasaki KLF300 and many others used one that high as well. For a second opinion on the 500 ohm pick-up coil theory, call Rick`s Motorsports and they will be able to confirm. https://ricksmotorsportelectrics.com/Trigger-Coil:-500-OHM-21_503  

Unfortunately, the PDF manual I have omitted the 1999 wiring diagram. I do have a factory manual at the shop on microfiche (yes, I`m that old 😀) but displaying it here would be difficult. Sorry for all the quote boxes, I accidentally added them and don`t know how to delete them.

Also, my replies are slow because I`m a newbie here and my posts must be approved by a moderator. You guys were there once 🙂

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[Mech]

Yeah ok thatoneguy, that continuity checker will do the job. It sounds like you know what you are doing... which isn't always the case in here.

So, if you go back to one of my early posts you will see I asked some questions about the key switch, the and how the starter circuit is connected to the cdi unit.. If you answer those questions either Gw or I will be able to find you a diagram that will work, and have the correct specs.

So far though, it does sound like the coil is open circuit. You should use two pins a little way down the wires from the plug and check the wires are't just broken near the terminals.. No point pulling the cover if it's not needed.

[Savage3]

https://www.ebay.com/itm/185463997787

Not much time, cheap replacement CDI in case ya need it. 

Check either side of circuit as previously mentioned before purchasing part.

Many times it's a bad ground, not CDI itself. 

This is just in case ya need it. 

Verify that it is correct part! Description states it fits 96-99 Big Bear 350

[thatoneguy12345]

I cut the White/w green line and the white with red line about 2 inches outside of the stator housing. Still nothing, open circuit. I have purchased one of the parts from Ricks and will install later this week when the gasket and pick up coil come in. Any tips/tricks for the housing? It looks like there is a clutch adjustment nut on the side of the housing.... ( I think that is its purpose). Its a threaded end with a slot and a nut on it. Housing has a decrease/increase arrows. Does it have to be removed entirely prior to opening the housing? 

[Gwbarm]

I did find another repair manual but it wasn't for the 350UB, and looking at the wiring diagram the plugs were not the same as your. 99 must be a strange one, maybe an odd year before the 400. I did find an owners manual for the UB I think it was maybe UBW looked through it and no wiring diagram.

May just have to old school this one, check all your coil resistances to make sure they are in spec, check that you have continuity on all your wire, make sure you have 12 volts to CDI and good ground at CDI, check to make sure all the stator coils for ignition are putting out voltage. Check start stop and key switch for correct operation. Make sure you have 12 v and continuity to ignition coil. I know all this has been talked about already I was just going through my check list when I don't have spark. Im sure you have already checked most of these things.

So when all of these things are in spec, then it's time to replace the CDI, but before I did that I would pull the side cover and make sure pulser coil is in the right position and not loose, with no problems there no trash or metal flakes obstructing it, that's a test you can only run with your eyes. 

[Gwbarm]

You might want to take a look anyway, poor photos, 

 

[Mech]

Yeah I looked too Gw and found the same owners manual.. no diagram.

As for it being an odd one for the year, I'd suspect it's because it's for some other market.

Some countries enter into trade deals where they get to contribute some local content to the build. It's quite often electrical or electronic components. Apart from a trade deal, some markets just get different spec bikes than america gets.. Here in NZ we get machines spec'd for america, asia, japan, australia, europe, GB, africa... oh.. and New Zealand.

If we identify the specs and systems the bike is using though, then we can identify parts and tests to fix them..

[Gwbarm]

After reading the specs from NRAs manual, I thought it was going to be closely wired to the 400 because the specs were about the same, but the CDI is definitely different. 

[Mech]

Yup.

At the moment it is certainly sounding like a break in the wire or winding though..  And if I'm right about what the resistances are meant to be, then a 500ohm winding is certainly not going to be the cure.

[thatoneguy12345]

Welllllllll I got my new 500 ohm pickup and got it installed. I got spark back!! I was able to get it to run on starting fluid. Immediately after it started running though the gasket failed on teh stator cover and left a nice puddle on the floor. lol. Now time for permatex!! Thanks Everyone! 

I will post again when I finally get it all up and running and make sure the spark stays. 

[Gwbarm]

Glad to hear you got your spark back, the same thing happened to me with the Gasket on my Bear. That lower area has to be extremely clean, I went over it with a Razor steel wool and polished it with 600 grit sandpaper and wiped down with brake clean to make sure no contaminants were left behind, to get mine clean, and put on an OEM gasket instead of the aftermarket one I had on there. The OEM one was not that much more and I didn't have anymore leaks.

[Mech]

Ok..  Glad that worked.

I use loctite master gasket and that stuff just  needs the surfaces wiped with a dry cloth and it sticks, and it never never leaks. It fills gaps up to .013", and doesn't block selves.

[Gwbarm]

Glad to hear that I will try it, I have used many and have not been impressed with any of them, so I just take my time and use them dry. The last one I used was Indian head gasket shellac, what a gooy mess that was.

[Mech]

Ha..  They still make shellac !

I tell you mate, once I found loctite it's been the only thing I use except for gasketless sumps that need silicon. And serious, you can put it on oily metal after a quick wipe, it will even stick to oily surfaces, but a wipe is better, and after hundreds and hundreds, thousands probably, of applications, in high test situations, I've never had a leak.

[NRA4LIFE]

21 hours ago, thatoneguy12345 said:

Welllllllll I got my new 500 ohm pickup and got it installed. I got spark back!! I was able to get it to run on starting fluid. Immediately after it started running though the gasket failed on teh stator cover and left a nice puddle on the floor. lol. Now time for permatex!! Thanks Everyone! 

I will post again when I finally get it all up and running and make sure the spark stays. 

Super

[Gwbarm]

I couldn't find Loctite Master Gasket , is that the same as Loctite 518 gasket maker 

[Mech]

Yes. The syringe is the best applier. It cost a bit more than other products but it is exceptionally economical in use because it takes so little and applies so cleanly and nicely.

https://twlnz.co.nz/loctite-518-gasket-maker---medium-strength---25ml/?setCurrencyId=1&sku=51827&gclid=EAIaIQobChMI1qjBrMqbgAMVFq2WCh2Vugf1EAQYASABEgKpmfD_BwE

You could throw every gasket but the head and cyl base gaskets out and use this on quad motors, big mo\tors with the gears and all, and it would do four overhauls easy.

[Gwbarm]

I see it does say master gasket, i havent found that one yet, thanks for the link. 

[Mech]

I've used it on big load bearing flanges on heavy machinery, and right down to the tiniest stuff.. never had a single problem of any sort. It's sensor safe, high temp, resists and seals anything, air pressure, oil, petrol.. 

I don't recommend it until you have tested it and know how little it will need, but because the small amount of excess inside the joins dissolves into the oil it can be used with caution on the likes of diesel and auto trans joins, it doesn't block sieves or seize the likes of oil pressure relief or injector nozzles..

 

[thatoneguy12345]

I can confirm the quad is fully up and running now. Thanks Everyone. I have two follow up questions. 

Is it normal the charging voltage output is only 13.5V? 

Is it common that the neutral lights go out? I can still start it, which means it has to be in neutral, but the light has gone out. Any thoughts? 

[Mech]

That 13.5v is fairly common. Sometime is you just rev them ever so slightly while you are watching the voltage they go up above it then if you rev them more it goes down again. batteries are meant to be charged to 14.7 for a full charge, but then once they regulate it's to 13.5. As long as it holds it at 13.5 with the headlight on, and perhpas a few revs, then it's putting out enough current and it will be fine.

Have you checked the bulb ?

[NRA4LIFE]

13.5 volts is a bit low if your battery is healthy and fully charged. As Mech said, 13.5 can be adequate, but 14.5 volts (give or take) is what it should be putting out ideally. Try this, after the ATV has sat not running for 15 minutes or so, see what your battery voltage shows. A fully charged battery will show about 12.25-12.5 volts. If it does not, then unhook the ground and give the battery a charge. A lower amperage charge for a longer time is best. Then retest. If it does show fully charged then just keep checking it from time to time. If it does fail at some point, given the fact it is a magneto CDI system and has a recoil starter it won`t leave you stranded.

 

As mentioned, the neutral indicator bulb would be a prime suspect. The aren`t exactly a common bulb, so to do a quick check you can often put the reverse indicator bulb in.