mower no blade adapter won't start


  #1  
Old 07-30-19, 05:25 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,682
Received 11 Upvotes on 10 Posts
mower no blade adapter won't start

I acquired a used Craftsman GCV 160 (model 917.370600) lawn mower of which the blade adapter was broken, and the screw (bolt) that bolts it onto the shaft. I was told the mower is a good running engine and operated fine until the blade adapter and the bolt broke as they did. Anyway I can easily order up these replacement parts needed. For the heck of it I went ahead and tried starting the mower without the blade/adapter just to see it run. It started right up very nicely and ran good. Then I stopped it for a little while and then I tried starting it again. It does not want to even begin to start anymore. I read the troubleshooting in the manual and it said one reason for the mower not to start would be that the blade adapter is not attached. So I'm wondering if in fact that is indeed what is preventing the mower from starting. The blade adapter is a fairly hefty/heavy piece of steel that slips onto the shaft in the keyway. Does the engine somehow "sense" the adapter is missing and so will not start when it's not there; something to do with proper balance or whatever?
 
  #2  
Old 07-30-19, 06:56 PM
G
Member
Join Date: Jun 2006
Location: United States
Posts: 2,296
Upvotes: 0
Received 31 Upvotes on 29 Posts
The adapter and blade are the flywheel for the engine and supply the proper centrifugal force when cranking the engine, usually the starter rope will kick back if the blade is not installed. If it started without them it may indicate a sheared flywheel key. Have a good one. Geo
 
  #3  
Old 07-30-19, 07:52 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,682
Received 11 Upvotes on 10 Posts
Okay I see, the blade and adapter act as the flywheel for the engine. Thanks, I get it. Well the starter rope did indeed kick back, and quite sharply I must say, most times after I tried starting it again without the adapter and blade installed, as I mentioned. It did start and run that one very first time only though, for some reason, without the adapter and blade. I'm thinking of ordering up a new adapter (and fastening bolt) and then replace those broken parts and hoping that fixes it. But perhaps not if there's a sheared flywheel key. Any good way to determine without complete disassembly to determine if the flywheel key is indeed sheared?
 
  #4  
Old 07-31-19, 07:35 AM
G
Member
Join Date: Jun 2006
Location: United States
Posts: 2,296
Upvotes: 0
Received 31 Upvotes on 29 Posts
If the engine kicked back when you tried to start it I would say the key is fine. Have a good one. Geo
 
  #5  
Old 07-31-19, 07:50 AM
A
Member
Join Date: Jan 2013
Location: U.S.A.
Posts: 1,902
Received 73 Upvotes on 66 Posts
Odds are probably pretty good that you'll be fine with the adapter and bolt, and I might get those and see how it does. But if they did break or damage the key as well it's not a big job, certainly a long way from complete disassembly. Once you remove the top shroud, with the recoil intact, you'll be looking at the flywheel, and can look straight down the keyway. If you did need to remove it at that point you would need just a socket and puller.
 
  #6  
Old 07-31-19, 08:25 AM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,682
Received 11 Upvotes on 10 Posts
If the engine kicked back when you tried to start it I would say the key is fine.
It seems in a big majority of info/videos etc I'm finding online that one of the most common symptoms of a sheared flywheel key is when the starter rope kicks back forcefully when trying to start (which is what's happening now). So a little confused now about that contradiction.

Odds are probably pretty good that you'll be fine with the adapter and bolt, and I might get those and see how it does. But if they did break or damage the key as well it's not a big job, certainly a long way from complete disassembly.
Ok... will proceed as above.
 
  #7  
Old 07-31-19, 11:33 AM
G
Member
Join Date: Jun 2006
Location: United States
Posts: 2,296
Upvotes: 0
Received 31 Upvotes on 29 Posts
If it kicks back when the blade is installed yes it would indicate a sheared key, the engine fires just before TDC so without a blade there is nothing to supply centrifugal force to continue, after hitting something the sheared key moves the blade farther back from TDC (retards) the firing is then so far before TDC that it will kick back. Have a good one. Geo
 
  #8  
Old 07-31-19, 12:15 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,682
Received 11 Upvotes on 10 Posts
I see. Thanks for the helpful replies Geo, and pedro. Got some parts ordered up, they're on their way, and after installation I'll post back with anything pertinent.
 
  #9  
Old 08-31-19, 02:29 PM
sgull's Avatar
Member
Thread Starter
Join Date: Nov 2007
Location: AK
Posts: 2,682
Received 11 Upvotes on 10 Posts
Just an update; got the new adapter installed, finally, along with the blade. No hard kickback on the starter rope now, and starts right up and runs like a champ. thanks all.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: