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  #1  
Old 10-03-2007, 11:33 PM
scaghydro scaghydro is offline
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Location: LaGrangeville, NY
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Kawi FC420V questions

Hey, all

Im new to the forum and need help with my SCAG 52" Hydraulic walk behind. It has a Kawi FC420V recoil start motor.

It has been having trouble starting lately, backfiring through the carb and exhaust...so I took the carb apart, cleaned it with carb cleaner and put it back on...still same problem. Adjusted the valves (.006?) at tdc on compression, still same problem. changed the fuel filter..plug....air filter...still same problem.

The grass is very long!

I also adjusted the air gap on the ignition module and taped any worn areas on the wires leading to it...

Once it is running (If I keep at it long enough, 3 or 4 sessions of recoil he!!) it runs like a champ.

It sounds like a fuel delivery problem, but theres the backfiring issue which sounds like the valves.....but then, once its running its fine?

I have gone so far as to take the head off and clean the carbon, etc...but all looks better than I thought. Should I take to valves out (dont know how) and clean them? I think the head bolt torque is 38 lb/ft. for putting it back together....

I really should get a manual!

Any help would be greatly appreciated!

thanks very much

JP
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  #2  
Old 10-04-2007, 04:53 PM
khouse khouse is offline
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Have you changed the spark plug?
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  #3  
Old 10-04-2007, 05:54 PM
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Restrorob Restrorob is offline
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You have set the valves properly and to the right spec,

Not very common on belt drive units but could happen, Have you checked for a partially sheared flywheel key ?

If you use the search feature on top of this forum you can find a link to a PDF service manual I posted a while back (can't post them any longer).

BTW, Welcome to LawnSite !
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Old 10-04-2007, 08:51 PM
scaghydro scaghydro is offline
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thanks for the input

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Originally Posted by khouse View Post
Have you changed the spark plug?
Yes, new plug but I have not tried it since I took the head off.....

thanks

JP
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  #5  
Old 10-04-2007, 08:55 PM
scaghydro scaghydro is offline
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double thanks

Quote:
Originally Posted by Restrorob View Post
You have set the valves properly and to the right spec,

Not very common on belt drive units but could happen, Have you checked for a partially sheared flywheel key ?

If you use the search feature on top of this forum you can find a link to a PDF service manual I posted a while back (can't post them any longer).

BTW, Welcome to LawnSite !
Hi, Restrorob,

I checked the clearances 3 times thinking I must be doing something wrong, but they are right on.

I have not checked for a partially sheared flywheel key yet, will do that tonight....

Ill also check out the PDF link you mentioned....should help quite a bit!

thanks very much, Ill let you know how it goes!

JP
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  #6  
Old 10-10-2007, 05:13 PM
scaghydro scaghydro is offline
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Location: LaGrangeville, NY
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checked the electronics.....

Thanks, Restrorob for your guidance in fixing my 420V. I have the head back on, valves adjusted etc.

I moved on to the electrical system and found the coil to check out but the control unit is testing a bit low ( 300ohms on the 1x for the case and 35ohms on 1x for the terminal. This seem closer to the control unit on the 460V manual you posted a while ago, but I used the values you posted not long ago for the 420V....) for the 420V (recoil start) The unit has BM11 stamped on it, if this helps at all....I think I will try to see what kind of spark I get as I replaced the plug, plug wire and terminal end.....


Am I on the right track?

thanks again for your help!

JP
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  #7  
Old 10-10-2007, 06:51 PM
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Restrorob Restrorob is offline
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Originally Posted by scaghydro View Post
Am I on the right track?

It appears you are, That would have been the next step.

If the igniter is testing low then it could in fact be firing at the wrong time causing the back-firing.
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You never learn anything until you admit you don't know it all...
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Originally Posted by MannsLawnService View Post
some times the man in my mirror isn't so smart...
"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!
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  #8  
Old 10-11-2007, 10:13 PM
scaghydro scaghydro is offline
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Its alive!

Well it runs better than it ever has in its life.

Just to recap....changed the head gasket, plug, plug wire, fuel filter, oil filter, oil, air filter and element, cleaned the carb, painted the muffler and cleaned it from stem to stern.

I ended up getting a new multi tester and decided to check the wiring while I was at it. All the grounds were good, safety switches good, key switch.......bad!!!!!. Well, when I say bad, I mean intermittent. (just like the starting problems I was having!!!!!)

Even if the easy to check and simple little key switch WAS the problem all along, I have learned some valuable troubleshooting tips. Preventive maintenance is the way to go!

Thanks for all your help, especially restrorob. It started on the first pull with very little gas in the carb and an empty fuel filter!!!

JP
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