I have a YSM 8 , my starter solenoid is shot, to start ,I cross with pliers and starter works fine & starts fast. This summer I decided to order a new starter off Ebay $120.00 , Only it wouldn't start the motor ! turned it over but would not do the trick- So I changed back & starts just fine as long as you don't mined the pliers . Has anyone else had this problem or did I just get a Bad starter? --Dale
You probably have a bad/corroded/high resistance starter 'primary circuit' ... and there is enough 'voltage' getting to the solenoid to 'energize' it. This is a VERY common problem with older Yanmars. Yanmar used non-tinned wiring in the 'control panel' ... and over time wiring, the keyswitch, the 'pushbutton, and the in line fuse (and fuse holder) become corroded and oxidized .... hence 'voltage drop' at the solenoid. If the solenoid works 'well' when 'jumped' then most commonly there is lots of 'electrical resistance' in the starter-solenoid primary circuit: Battery-->key switch --> starter button --> fuse (usually mounted on the engine) and ALL the wiring and wiring connectors in this 'circuit'.
How to assay (use a digital voltmeter)
1. Measure battery voltage AT the batt side of the keyswitch, use a good electrical ground when measuring.
2. turn key and measure on the 'solenoid side' of the keyswiitch ..... if voltage is markedly lower - replace switch or clean switch connections, etc.
3. measure at batt side of 'push button' .... push the button and measure voltage on the 'solenoid side' .... if voltage markedly lower, either clean the carbon off of the internal contacts or replace the switch.
4. fuse holder .... clean connections / replace as needed .... best is to replace the entire fuse holder.
5... etc. etc. etc.
Repeat voltage drop test on the (heavy gage) 'secondary' wiring to the starter ... do the SAME on the 'ground' circuit - ALL the WAY back and including the batt. negative/ground terminal.
Resistance (corrosion/oxidation) in the primary or secondary circuits will cause the voltage to be lower .... and the amperage draw higher (power = amps X voltage)
As needed, replace wire with tinned wire of 'heavier' wire gage. Use tinned replacement connectors. For extreme reliability replace/rebuild the ENTIRE 'primary circuit'.
;-)
