Yamaha Bear Tracker With a Weak Spark

On a recent hunting trip, this Yamaha Bear Tracker would not start and had a weak single spark, so I decided to troubleshoot and test the ignition coil, kill switches, magneto, and the CDI unit.

[@joseacd01]

Thank you for your video help me a lot, i got my spark back thank you

[@romanykemp9042]

I thought I was having intermittent issues with my ignition on my Yamaha Big Bear 400 - 2001 model - and I checked out this video an found it very helpful...I ended up rebuilding the carb and a few other things and the issue so far as not occurred again. But I was frustrated that there is so little info about input and output voltages of the CDI that you might be able to test - and wanted to list what I found out for mine. For my CDI you have a stator input voltage - that powers the CDI - it mostly a sine wave. The pickup pulse input trigger from the stator is just that - more of a pulse and not a sine wave. You can't really measure non sine waves with a volt meter - but you can buy a "peak voltage adapter" device to connect to your volt meter - and does what it implies - it shows you the max voltage that it sees - and converts to a DC output. Ebay has them them for around $25 - rmstator has a much better one (as far as quality leads, etc) for 2X. But getting back to what voltag elevels I saw on mine using the peak voltage adapter - the stator input voltage - cranking - to the CDI was 1.3 VDC - goes up to 10.8 at about 3000RPM. The pickup coil voltage was 5.5VDC when cranking - to 15VDC at 3000 RPM. The Output of the CDI - going to the coil was 2.05VDC when cranking - and 3.1VDC at 3000RPM. For the 3 phase stator I would see 12.5VDC phase to phase. Don't recall what I saw at 3000RPM - but pretty sure it was close to 30VDC. Hopes this help.

[@masonvosburg2546]

Had this problem with mine, small crack in the silicone on the cdi box caused moisture to get in. Spend the money for a nice one, makes a world of difference

[@nathanielcyrus3577]

Did a new CDI box solve the problem? I’m having the same exact issues on my bear tracker. New carb, new air filter , new lines and petcock. Tested for vacuum leaks and all good.

[@SmallEngineDIY]

I purchased an aftermarket CDI box on Ebay that did not work at all. No spark at all. I think the aftermarket CDI was out of spec. So, I sent it back and will look for one that is within spec that doesn't cost a fortune. I heated up the old box again, and so far, it is working.

[@chk1chk2]

Have you replaced the CDI with another unit yet after returning the eBay one? What kind did you end up going with if so?

[@billlester3088]

High, when testing the magneto and probing the connector from magneto you did not show the ohm meter lead connections, where was the ground lead connected to, was it grounded to engine case?

[@bartrowe3705]

A year later and I have the same issue, What pins (wire color) was check with which lead of the meter? Don't want to tear into something if issue is elsewhere. Thanks in advance. Please list what the specs show to be acceptable on each reading.

[@evdath3473]

thanks

[@terrylindsey6955]

Cute man

[@user-tl5uu5hf7z]

I need help mine has no spark I don’t know what to do

[@bradrayburn8304]

What year is this Bear Tracker?

[@SmallEngineDIY]

1999

[@TheBrownDoggie]

CDI part # F8T09273

[@jordon7813]

Mines not getting any spark at all

[@j.p.foleyjr.6333]

Hey mine either...was running fine...now it sounds like I'm trying to start it with the off and run button switch off.... sounds like that...I can't figure this shit out..my ignition is fine ...

[@j.p.foleyjr.6333]

@@foreverday9798 it was wiring...plus my fuse wasn't blown on the battery but needed changing...best way to find out Ifound out is , put it on start and use the pull start cord