1990 Yamaha 150, won't start, no spark

[wllgren]

Rodbolt and friends, Striper fishing yesterday in inlet. Couldn't get port engine started. Appears to be no spark to any of the cylinders. Could it be the CDI unit? Dual engines with one control unit and one kill switch. Starboard engine stars fine. Local marina has a CDI unit for a 1990 200hp Yahme. Are they interchangable? Any other ideas? Thanks.

[rodbolt]

no spark could be a number of conditions, one of which could possibly a CDI, could be a trigger or a stator as well. could be as simple as a shorted kill circuit wire or a bad keyswitch. what inlet are we discussing ? I would invest in a sparktest, a DVA output test of the charge and trigger coils and a short to ground test of the trigger coils and charge coils, should take less than 1 hour to perform all the above tests and isolate the failed component. look at the yam parts website for the CDI compatability.but do a spark test first, sometimes the oring on the engine side of the quick connector will fail and shut off fuel to the engine. test everything,should take less than an hour and replace the defective part, barring corroded fasteners the yam stator can be replaced in about 45 min and the CDI in maybe 20 min.with proper testing the labor bill should be less than 2 hours. barring corrosion factors.

[wllgren]

Rodbolt,Thanks for the quick reply. Little Egg Harbor inlet in South Jersey about 10 miles north of Atlantic City. Pardon my ignorance but what's a trigger and stator? Can I do the sparktest myself? One of my problems is that it's hard to find a mechanic this time of year as most are busy winterizing boats for the season. I'd like to get back in business and fish for the next few weeks. Where does the kill switch circuit wire go on the engine? How do I check that? The contol unit is the standard Yam 701. Could the keyswitch be bad if the engine cranks fine? The CDI replacement looks like something easy that I could do myself. Is it worth taking the one from the good motor to check out that angle or is it not worth the effort? Thanks for your help.

[wllgren]

One more question, what is the yam parts website address?

[rodbolt]

CDI failures on that motor are incredibly rare. so are trigger failures. do a search on the site for "homemade spark tester". you will need a DVA meter or a DMM with a DVA adapter and the servie guide or at least the tune up spec booklet. most any tech with the guide, can test it. its a very basic CDI ign system. but it does require specific test equipment. http://www.yamaha-motor.com/outboard/parts/home.aspx

[Ray Neudecker]

Yes the cdi's will interchange. Failure rate is almost nil on them though. First as rodbolt said be sure it is not firing. If the battery doesn't spin the motor fast enough it won't fire. Be sure it is up good.

[rodbolt]

ray I need a good freshwater block for my 89 225 excel. any ideas where I could find one? either that or a need a rebuildable block assy for a 93 200. I gotta build a motor for my hydrosports. I have an 89225 excell that has a hole corroded in the crossover tube but runs well and a 93 200 with a wristpin through the cyl wall into the water jacket.

[wllgren]

Thanks guys. You've convinced me that its probably not the CDI unit. Maybe its something simple like the kill switch circuit. How do I check that out? I can locate the wire on the key switch assembly but where does it terminate at the engine? Is it under the cover for the CDI unit? By the way Ray, I did check the spark at each cylinder with a spark test device - no spark. Thanks for all your help.

[Ray Neudecker]

A simple test would be to disconnect the ground wire from the kill switch to eliminate the switch itself. Rodbolt, I have a complete 92 or 93 225 that needs a piston. I don't have a Excell block I can let go, but do have a cherry block I can make one out of for you. Email me at neudecray@hotmail.com for more info or for phone number. I have about 15 blocks right now and should have no problem taking care of you.

[rodbolt]

dissconect the 10 pin ign harness. disconnect the brown lead at the stater solinoid. jump the brown solinoid lead to the battery lead on the solinoid to crank the engine with the spark tester installed. if you now have spark it may be a problem in the kill circuit. if the alarm horn is working and you attempt to start the motor with the white kill circuit wire grounded or its shorted you will get an alarm at cranking.next will be to check the stator CDI charge coils for input to the CDI. then the trugger coils for input to the CDI. good inputs with no outputs leads one in the right direction. the resistance on the low speed charge coil should be something like 740 ohms, wire colors are brown and red and are in a 4 pin connector at the CDI. check for shorts to ground on both wires and check for proper continuity between the two. a better test will include a cranking voltage output but that will require a DVA type meter