[Hooquai8]

With help from this forum I tested the ignition coils, CDI unit and the stator. Aside from a little corrosion, all tested well. Somehow I just KNEW it was an ignition problem, but just couldn't find it.

[Enky1974]

The fuel system is COMPLETELY new - new tank, new hoses, new water separator, new fuel pump, carbs clean as new. Ethanol free fuel used exclusively in this motor since I've owned it (10 years).

[hairtransplants789]

I'm new to the forum, but have searched and not found my answer.

[Matthias Vance]

I did test all three coils and found them all to have the same resistance on low and high sides, so I assume they are functional. I did find minor corrosion on the ground connections where the coil wire is grounded to the engine, also corrosion in the spark plug connections. I have sanded/polished all connections and reassembled with silicone grease, but have not had the opportunity to check it out yet. here

[BlueSky]

I have been working all summer to sort out my c75. It will sometimes run just fine, sometime miss badly and bog down under load. The fuel system has been completely replaced (leaking tank) and the carburetors have all been cleaned and synchronized. [links]

[harley4noble]

My experience has always been that thorough troubleshooting eventually gets to the solution, even when it is not what you expected.

[victoriaw]

See that rectangular bump on the flywheel rotor of this Yamaha Vision? A magnetic pickup senses it as it goes by. Jetav8r.com photo.

[wizeman]

Here's a CDI box in a dirt bike. You'll often find them lurking under your seat. Andy Greaser photo.

[Prze_koles]

Black box, brain box, pulse pack, igniter box, CDI module, power pack, whatever you want to call it: if your motorcycle is newer than 1980, it probably has a black rectangle spouting wires under the seat that makes the magic happen. If you're lucky, you're reading this for your own education. If you're not, you're wondering what a CDI does. because you suspect yours doesn't. Let's take a look inside.

[marywilliams937]

That's all great, but the jump to CDI was like going from carburetors to fuel injection. Electronics gave manufacturers new control over their engines. The ignition advance, once mechanically limited to a curve, could be tuned to squiggle any way you liked all the way to redline (read Lemmy's timing article if you'd like more on this). Increased power, better efficiency, less maintenance, and fewer moving parts earned CDI, and systems like it, a good reputation. But that doesn't mean they stay problem-free.

[aksjfhasdkfjh8]

The key is eliminating every variable until only the box remains, because they’re not easy to troubleshoot. Most are sealed up like a sarcophagus. These systems are supposed to be maintenance-free, but even a loose trigger sensor can mess with your bike’s little brain. Some manufacturers give specs for testing your box pin-by-pin, but don’t count on it. The best solution when troubleshooting black boxes is to replace a suspicious one with a known good part after checking the other possibilities first. Be careful when buying replacements. An eBay special may have the same issue as yours, and a new replacement may not be returnable once installed.

[tenbagger]

Sure, there are aftermarket options for all kinds of applications. Most offer more power, and the best units come from reputable tuners. Do your research before buying one. You can also gain power by keeping your stock box, but using an ignition advance kit to alter the trigger mechanism. Again, read up on safe options for your motorcycle before attempting. I've tried both with good results.

[costner1367]

The CDI ignition pack contains a digitally-controlled NON-CONTACT design to the circuit of the timing sensor linkage, eliminating the moisture issues found on the OEM design! Basically, we made this ignition system water resistant.

[romsek]

We are continuing to expand our line of Yamaha outboard ignition components to support service professionals. As the older Yamaha engines are entering their service life, we offer a broad coverage of parts that are available in stock, to keep your customer on the water.

[MrFlibble]

So, what does this mean? When this ignition would fail, you would end up with a high speed miss, the engine would not advance timing, or the engine would not start, leaving your customer frustrated.

[theymos]

Used power pack cdi outboard motor YAMAHA 25HP 4S 65W F25 F25AET 65W-85540 65W-85540-20 65W-20

[tehlaser]

ECM CDI YAMAHA 115HP 4S 68V F115 68V-52 68V-8591A-52 F8T94272

[jesmurf]

Used power pack outboard motor MERCURY MARINER 90HP 4S 4 CYL. 90ELPT 2000 75HP 90HP 100HP 4S 804269T YAMAHA 80HP 100HP 4S 67F00 67F-85540-00 F8T35571 [links]