2001 Yami 25hp - no spark

[deltadawg]

2001 Yami 25hp - no spark

Hi and thanks in advance for your help and suggestions.

I have a Yami F25TLRZ with a 703 remote. It ran fine last month, last week it would not start, it would crank but not

fire. I had limited tools with me but I did replace the plugs, the ones I took out smelt like fuel so it was getting

some fuel in the combustion chamber. I noticed a big bubble in the fuel filter under the cowling, I have a 10 micron

external filter too which I replaced 9 months ago.

I had not seen that bubble in the filter before so I ordered a new fuel pump and hoses.

After boning up reading my Yami service manual and Clymer manual and armed with more tools I did some additional tests

yesterday.

I had gotten 1 of those Harbor Freight spark checker, and using the old spark plug ground down the tip so my ignition

wire would mate nicely and I made a bushing with a copper connector for the checker's pig tail. I previously checked

it on my lawn mower and saw a nice orange light. I had made a primitive spark checker out of back to back 30 amp

alligator clips and an old spark plug from my Yami. With the boat still in the shed in dry storage where it was nice

and dark I cranked and didn't see a spark from cylinder 1 or 2 and yes I had my homemade alligator clip checker cliped

to the block for ground. I got 1 of those inductive pencil like spark checkers from Amazon in the mail when I got

home so I will have it for the onboard tool tote bag.

Pulled the boat over to the wash station to work in the sun with more light and test some other things.

Compression 180 psi dry (no oil squirted in) cylinder 1 and 185 psi dry cylinder 2. I didn't do a wet test since the

compression was within spec 170-190.

Its hard to get to the fuel pump test port to clip the cable tie so I pulled the line going to the carb hooked up fuel

pressure test gage hose and cranked and it squirted into a tin can nicely, hooked up the gage and got 5 psi. I guesss

I don't need the new fuel pump and hoses that arrive today but it is nice to have my own spares on my garage shelf.

Back to the no spark.

I pulled the ignition coil, primary resistance measures 0.4 ohms spec says 0.08 to approx 0.11. I didn't have a peak

voltage checker but I put my voltmeter on 200 volt scale and measured on the wires from the CDI to ignition coil and

measured 0 volts spec says 152.

I didn't have the manual for my 703 remote but I see that kill switch laynard in the schematic so will look at that

next time. Removing and replacing the laynard didn't change the behavior it still cranks without firing.

How do I order one of those new 703 remote kill switches from iboats.com?

How do I order from iboats.com test harness YB-06768 and peak voltage adaptor YU-39991?

Should I order a new ignition coil because the primary resistance I measured was out of spec?

Do you think the problem could be the CDI unit and/or pulser coil, do they go bad after 10 years?

Thanks again for your help.

 

[99yam40]

Re: 2001 Yami 25hp - no spark

Always test things before buying parts that are not needed, It gets expensive enough just buying the ones you need.
You can use a small stiff wire like paper clip or stick pin and work it into the back side of the connector where the wire goes into the connector, just be careful not to damage the insulation on the wire. Then hook the DVA adapter and meter to that to get the readings.
Could be a bad switch(key or kill), bad wire, bad charge or pulser coil, bad CDI or coils. just need to test to see. There are lots of places to get the DVA or build your own

 

[deltadawg]

Re: 2001 Yami 25hp - no spark

Thanks 99yam40 I hadn't thought of the key switch it could be the key switch. Good advice on not buying the parts before I do diagnostics, I was just getting ready to spend $400 on a CDI, pulser coil and ignition coil and it could be the key switch.

I will make copies of the schematic from the 703 operation manual and the F25 service manual buy or make a peak voltage adaptor and take continuity, volt and resistance readings and annotate the drawings until I figure out what is going on then order just the parts I need. It will still be faster than being dependent on a marine shop and I will understand my ignition system well when I am done.