Riding mower

[woodbutcher]

My brother-in-law has a Craftsman 18.5hp V-twin mower that is 8 years old. It starts and runs good sometimes, other times nothing happens when he turns the key. He's replaced the ignition switch and the starter relay with no change. The problem appears to be in the safety switch connected to the clutch/brake rod. Since the switch works fine sometimes, I'm wondering if the problem might be in the linkage instead of the switch itself.
I posted this question on the Hobby Talk website where there are many knowledgeable small engine mechanics. I got 3 replies saying to change the switch. I have my doubts that will fix the problem. I think somebody would have experience with a similar situation.
Butch

 

[KSF]

You can check the switch with a volt-ohm meter. Pull the leads off and see it you have continuity when the switch is actuated. If you have continuity every time it is actuated then it is good. If it is inconsistant then adjust the linkage to attempt to make it work everytime. If there is still inconsistancy, then the swtich may have to be changed.

 

[Anonymous-0]

Post on Garden Tractor forum, below. Tom

 

[dhermesc]

Face it, its an 8 year old chinese made switch that was subbed out to the lowest bidder. Replace it (or by pass it) before you start spending time and money chasing other parts.

 

[Revredneck]

Butch,
Checking the switch with an ohm meter will probably not tell you what you need to know. The most accurate way to check an intermittent switch is to use a voltmeter on the leads while it's under load. Probe first one lead, then the other while you're holding the key to the start position with the clutch pedal depressed (this may require a helper). Sometimes a switch will show continuity with no load, but then fail when the current starts to flow. HTH.
Good Luck and God Bless,
Tommy

 

[woodbutcher]

Thanks for the info. I'll pass it along. ( I didn't know there was a Garden Tractors site.)
Butch

 

[souNdguy]

I agree with the others.. ohm the safety switch...

soundguy

 

[Anonymous-0]

woodbutcher, I had a simiar problem on my mower with a techumseh engine... it ended up being a bad ground... sometimes this is overlooked on small engines. Make sure the battery cable has a good connection on both sides, and that the engine is grounded to the frame.