Three other areas to add to the check list. Carefully check the wires from the plug to the clutch. These control wires have a habit of becoming frayed/breaking. Once the wires break where they enter the clutch, it (the clutch) is junk even though it is still good. I'm still trying to figure out how to gain access to the wires inside(when they don't break outside far enough to make a splice) and then reassemble the clutch back to working order. Second, check all the connectors. They do not seem to be UV resistant. After several years they crack and can begin to cause intermitent shorts on the frame. If this is the problem, you can go to Radio Shack and purchase new connectors to replace the cracked ones. Much cheaper than buying a new wiring harness. Lastly, if everything checks out okay, put a voltmeter on the engine side of the clutch plug. It should read between 12-13 volts. THis will require a second person since someone will need to be at the handles keeping the OPC engaged, tranny in neutral and clutch engaged while you check the voltage. If not then then there is likely a problem with the capicitor (little round thing) or the voltage regulator(the rectangular black thing attached to the base to the right of the tranny) Or vice-versa. I don't know my way around with electrical things, but when I wasn't getting the proper voltage at the clutch it was the regulator) If you getting a constant 12-13 volts at the plug, then the clutch is probably going bad and is showing up as an intermitent failure.

 

WOW!

:blob4:

I will certainly check all of these out. I really appreciate your more-than-thorough answer.

I like to do all of my own maintenance when possible, because how can you properly care for something if you don't even know how it works?.... oh yeah, plus I'M CHEAP ... heh heh

 

I'm still trying to figure out how to gain access to the wires inside(when they don't break outside far enough to make a splice)

If you do let me know. I have dug down and done it but they broke again soon due to being shaved thin from the digging.

 

Also try to check th pto clutch gap adjustment, the clutch has three windows where you can insert a feeler gauge, the gauge thickness to use is .012-.014 turn the three nuts with the springs to EVENLY!! adjust the gap. If the gap is too wide the magnetic force of the clutch cannot hold it especially when hot!!

 

Some good answers - however, I believe your intermittent problem to be associated with the wiring harness connection - not the clutch.
I have spoken with Scag about my 36"wb doing the same thing.
The response - check the main connection in the wiring harness
where it all snaps together - look for evidence of a grounded wire or carbon tracing.
Apparently Scag uses smaller gauge wires in their wiring harness which cannot hold up to the heat and current load which then causes the blades to intermittently engage/disengage.
My fix was the cut out the factory plug, heat shrink better insulation on the wires, and solder the connections together.
I have no more problems - even in sustained operation above 100*F

 

How many hours are on the clutch? My Grasshopper was acting up sort of the same way. After it was hot, the clutch didn't want to engage. I'd let the mower sit and cool down. I'd even get the backpack blower and help get it cooled. After a while you relize its too far gone , and a new clutch had to be installed. I like the manual clutches that DC's use. Great idea!

 

Originally posted by bob
How many hours are on the clutch? My Grasshopper was acting up sort of the same way. After it was hot, the clutch didn't want to engage. I'd let the mower sit and cool down. I'd even get the backpack blower and help get it cooled. After a while you relize its too far gone , and a new clutch had to be installed. I like the manual clutches that DC's use. Great idea!

Scagg has intentionally engineered a failure in its clutch. The wires will break off at the clutch long before it goes bad. lol. All they have to do to fix this problem is make it a recessed spade connector on the clutch

 

My lazer had the same problem last year. It would sometimes start the blades, sometimes it wouldn't. I took the switch out and decided to take it apart. It was melting inside. I replaced the switch, and it has been perfect since. By the way, it is a cheap part.

 

I was surprised to see so many people having trouble with the wiring break.
in my experience it has always been the pto adjustment when the thing won't start or only sometimes when it is hot. Usually just make an adjustment and you are good to go. If the cluch is really old than you may have to replace it. We always check the adjustment 2x year and since we started doing this we have not had 1 problem with a pto clutch except for on an exmark rider which has no adjustment capablities.
just my experiences but i will look out for the wiring issue next time we have a problem.

 

I am having the exact same problem. Would you be so kind as to tell me what your solution was. I have already replaced the switch thinking that was it, but once I mow for about 45 minutes.......the blades disengage. Any feedback would be greatly appreciated...........

I have a Scag SW32. It has a 6-pole switch that engages the blades. The switch looks to be in good shape but occasionally the blades don't engage when I flip it on. It usually happens after running for a 1/2 hour or so - nice and hot. It never disengages when in use. Also, every once in a while a little jolt will kick it on. The blade-clutch is not loose, the bolt that holds it is on tight.

I am going to clean the contacts on the switch, but they look to be ok as I said.

Any other thoughts or ideas would help.

Thanks

 

I doubt you will get any reply from any of these guys, I have been on here most every day for over a year and never seen them post.

Have you performed all the checks they spoke of ?
If not that would be the thing to do, If you have any questions about anything they posed read this; http://www.lawnsite.com/showthread.php?t=144040 and do as stated and someone here can probably help.

Oh, Next time start your own thread.....most people won't even read these old threads.

And lastly welcome to LawnSite.

 

I doubt you will get any reply from any of these guys, I have been on here most every day for over a year and never seen them post.

Have you performed all the checks they spoke of ?
If not that would be the thing to do, If you have any questions about anything they posed read this; http://www.lawnsite.com/showthread.php?t=144040 and do as stated and someone here can probably help.

Oh, Next time start your own thread.....most people won't even read these old threads.

And lastly welcome to LawnSite.

Thanks for calling this to my attention Rob.

I'm afraid I did _not_ notice the age of the post until you mentioned it.

 

I was surprised to see so many people having trouble with the wiring break....

I can suggest a fix.
The wires break, I would propose, because of vibration. If you could silicone, or clamp, two inches, more or less, of the wires, where they "disappear" into the housing (of anything, not just clutches) to the frame or some other non-vibrating member, then the wire can break off someplace else without resulting in required replacement of more expensive component. Does that make sense?
Also, you can probably prevent any and all insulation cracking/disintegration by spraying, three times a year, with fluid film or Black Magic tire wet, which is an astonishing product IMHO.

 

Also, you can probably prevent any and all insulation cracking/disintegration by spraying, three times a year, with fluid film

Hey Jim, Are you on Dano's payrole now ? :laugh:

 

He may not be on the payroll but Jim will be getting a shirt! :laugh:

 

He may not be on the payroll but Jim will be getting a shirt! :laugh:

Bet you skipped right over my plug Huh good old buddy super pal of mine.

http://www.lawnsite.com/showthread.php?t=157082

 

He may not be on the payroll but Jim will be getting a shirt! :laugh:

... _YES!!!_ ...

 

... _YES!!!_ ...

 

Sore Loser!!:laugh: :laugh: :laugh: :laugh:

 

C'mon now Big Guy, quit your , you know I'll give you a shirt too so you can be in style. :waving: :waving: :waving:

Thanks for the plug, and don't forget Fluid Film is a lubricant, corrosion preventive and penetrant. It's the best stuff ever!!!

 

Yo Mr Dano
Who is my local distributor in 30533 zip?
That little sample can simply wetted my apetitt for the stuff and I have not axed everywhere, but the auto supply where I have axed does not carry.

 

Thanks Dan.....You da man

Hey Jimbo.....Ya see that

Oh.....Jim, You can check here for a dealer but I didn't find one within 30 miles of your place. But you can order on-line from here also.

http://www.eurekafluidfilm.com/locator/dealer.html

 

Thanks Dan.....You da man

Hey Jimbo.....Ya see that

Oh.....Jim, You can check here for a dealer but I didn't find one within 30 miles of your place. But you can order on-line from here also.

http://www.eurekafluidfilm.com/locator/dealer.html

Yea!
Thanks for tha' heads up, Ya dern redneck!:laugh: :laugh: