Weird Starting problem

[danklefsend]

I have a 2004 Yamaha 300 on my skeeter. engine runs great but recently will not start unless trimmed all the way up. started on a trip to mlax lake in MN. Any ideas please? also, at times when running on plane if you trim down it will kill the engine

[Nautical]

loose wiring ..bad connection . Check harness and all plugs .Anything pulling or binding ??Work trim up and down and inspect connections for looseness etc while going up and down.

[99yam40]

If you can find another wiring harness
you could plug it into motor and controls without running through rigging tube and under deck just to see if that makes a difference/
other than that it is trouble shooting with a meter if you have the equipment and knowledge

or take to a qualified Yamaha tech

[TownsendsFJR1300]

Please clarify, it doesn't start/RUN Or doesn't spin OVER.

As posted above, it sounds like the engine harness to main wiring harness isn't plugged in fully, corroded, potentially binding, etc. Un-plug and inspect those harnesses.

I would also recommend dielectric grease in each connector to prevent any corroding. Also physically remove/clean any grounds, (just looking DOES NOT COUNT either).

If the connectors pan out(no issues) time to dig deeper but start with the basic's

[danklefsend]

if motor is down it just clicks or a single click and nothing almost like battery is dead. once motor is all the way up then its full power
thanks for all the answers and ideas

[TownsendsFJR1300]

Please post back what you find, shouldn't be too difficult as the problem IS persistent.

[robert graham]

I've noticed that the nuts on the various relay lugs(some under plastic hex caps) can loosen and need checking/cleaning/tightening....some protective grease there is very good also....