No Spark Yamaha 250 0x66 2000

[Tireddiver]

Hoping for some quick diag suggestions after determining I'm not getting spark.
Anyone have a quick diagnostics or suggestions to finding out why I'm not getting spark???

This is the second time I haven't been able to get motor started. First time it appeared I was not getting spark but I switched out the plugs and chalked it up to either fouled plugs or me flooding the engine...

Used the boat twice since then without issue...now it's back and I determined I wasn't getting spark.

Unless it's a coincidence I think I either have some sort of intermitten problem or some component gave me warning and finally bit the dust...
Was hoping to find a "simple" way of isolating the issue before I go in circles attempting to use a manual and my very limited skills as a mechanic...

 

[DaleH]

1st - Check your battery connections, see: http://classicparker.com/phpBB2/viewtopic.php?t=7224

2nd - Check the OB fuse, where the main harness from the boat connects to the field devices

3rd - Check your ignitiion kil lanyard and kill switch. Quite a few guys I know this year had problems with both.

 

[Tireddiver]

All three suggestions check and re checked...although I will need to move away from the wing nuts I don't believe for the moment that that is the issue. But it is too simple of a fix to ignor and I will have the nuts & washers with me when I return.

The weird part on this is I returned again Saturday and could not get it started but was able to start it after doing nothing of any significance...went for a ride...returned to the dock and was able to start the engine repeatedly

Returned yesterday afternoon and back to square 1.
The starter appears to be providing plenty of revolutions ...but I get no spark at the plugs...is it possible to have a good enough connection to turn the starter and still not produce spark...

What could cause a lack of spark and only be intermittent.

 

[DaleH]

... is it possible to have a good enough connection to turn the starter and still not produce spark...

What could cause a lack of spark and only be intermittent.

Battery is weak or corrosion/resistance is built up in the wires or battery switch terminals. OBs will crank with <10 volts but new ones need 10+ and even 11+ VDC (on OBs with ECUs or electronic controls units) to fire.

 

[Tireddiver]

Ok...seems reasonable to me..I have already cleaned ALL the connections at the battery & starter...I haven't been back to swap out the wing nuts for NYLOK Nuts & Lock washers.

Would attempting to use jumper cables in order to by pass the actual cable to the starter be an appropriate test for the cables themselves? ...it was suggested by a friend...

My confusion is with the fact that it seems random & intermittent. I guess
I may be jostling the correct wire with my lame attempts and not realize it. :?

Thank you for your suggestions and being kind to a novice when it comes to outboards & the electrical systems of his own boat...

 

[Bucktail]

Everyone is giving you good advice.

Check the condition of the battery cables. The cables will corrode over time, and the corrosion can be hard to see because it is under the layer of the insulating jacket of the wire and will wick its way further and further up the cable over time.

I have seen this several times on boats as well as cars.