Thanks for this clear and concise tutorial. I have a slightly newer GX160 that runs OK, but has the kick back. I adjusted the valves (they were slightly loose) but it still has the issue. Now I know I need to check that flywheel key. I have had that failure on other small engines, but didn't think to check it on this one. I have no history on this engine, bought it at a yard sale for $30. It was a little dirty, but otherwise looked OK and was complete. If I can get it running right, it will sit on the shelf awaiting a future project.
Thank you. This is obviously a 4 stroke so the valve issue as cause of kick back does not apply to my arm ripper...I've heard something recently that is very counterintuitive: the less the timing is out (but it IS out), i.e. the smaller the degree to which the key and slot are misaligned, the GREATER the kickback. What do you think? I have a three wheel brushcutter, AS Motor, a beast, which frightened me with its violence. I 've read that kickback can injure people for a YEAR! Well, I looked at the key of this brute and it looked fine to me, but I was looking for an obvious misalignment thinking for a kickback like that it must be seriously misaligned. Some professionals have said you need to pull like a man, man! Erm, no thank you. I like my shoulder just where it is. I've refused even to look at the thing for the past 5 years as I walk past it. Got me an Orec. Thanks again. Reply
Ya those larger ones can be rough. I have known a few people who have broken a finger. If the key is good then something is jumping time. Was any work done on the coil? Could have been installed wrong or the cam could be damaged
my compression release broke when i was far from home, it took my 10 mins to start it and i nearly broke my wrist. getting over the fear its gonna kick back when i fixed it was hard 😂
Hello, I’m working on a gx 160 mounted on a thatcher. I checked the spark and it’s good, also pulled the flywheel to check the key, it’s fine. As you mentioned I also broke the handle off. I guess it’s time to check valve clearance now.
@@PNWSmallEngineandLawn The exhaust rocker arm was off the push rod. Set the proper valve adjustment to.008 and it’s running perfectly. Intake wasn’t out of adjustment at all 👍.
I feel your pain on the kick backs. I just had one that bruised my left thumb. The sump cover was busted so they owner had hit something real hard. So after I had swapped over to a spare cover and checked the cam out for any loose plastic gear and the lobes for the lift. All was good to go, so I thought. I went back into the sump again to check things out again. Still the same, very smooth without the plug installed. Anyway I didn't even think about the key after all that. Usually I will check those but this time I had taken more time than usual...oh well live and learn...maybe I'll put a string on my finger. I was looking at the pushrod on the exhaust side of your engine and I had thought the rod was bent when the compression release kicked in.
I’ve had several GX390 on small machines and the compression release arm was stuck tight Oil was terrible and metal shavings in it Keep the oil change folks 😊
Thanks for this clear and concise tutorial. I have a slightly newer GX160 that runs OK, but has the kick back. I adjusted the valves (they were slightly loose) but it still has the issue. Now I know I need to check that flywheel key. I have had that failure on other small engines, but didn't think to check it on this one.
I have no history on this engine, bought it at a yard sale for $30. It was a little dirty, but otherwise looked OK and was complete. If I can get it running right, it will sit on the shelf awaiting a future project.
Flywheel key would definitely be the next item in the list. If it has a newer looking coil it could also have been replaced and installed wrong
@@PNWSmallEngineandLawn Thanks, I will take a look at the coil while disassembling for the flywheel key inspection.
Thank you. This is obviously a 4 stroke so the valve issue as cause of kick back does not apply to my arm ripper...I've heard something recently that is very counterintuitive: the less the timing is out (but it IS out), i.e. the smaller the degree to which the key and slot are misaligned, the GREATER the kickback. What do you think? I have a three wheel brushcutter, AS Motor, a beast, which frightened me with its violence. I 've read that kickback can injure people for a YEAR! Well, I looked at the key of this brute and it looked fine to me, but I was looking for an obvious misalignment thinking for a kickback like that it must be seriously misaligned. Some professionals have said you need to pull like a man, man! Erm, no thank you. I like my shoulder just where it is. I've refused even to look at the thing for the past 5 years as I walk past it. Got me an Orec. Thanks again.
Reply
Ya those larger ones can be rough. I have known a few people who have broken a finger. If the key is good then something is jumping time. Was any work done on the coil? Could have been installed wrong or the cam could be damaged
my compression release broke when i was far from home, it took my 10 mins to start it and i nearly broke my wrist. getting over the fear its gonna kick back when i fixed it was hard 😂
Kick back fear is real lol
Hello, I’m working on a gx 160 mounted on a thatcher. I checked the spark and it’s good, also pulled the flywheel to check the key, it’s fine. As you mentioned I also broke the handle off. I guess it’s time to check valve clearance now.
Yes. If the valves are off it can cause some run or starting issues
@@PNWSmallEngineandLawn The exhaust rocker arm was off the push rod. Set the proper valve adjustment to.008 and it’s running perfectly. Intake wasn’t out of adjustment at all 👍.
I feel your pain on the kick backs. I just had one that bruised my left thumb. The sump cover was busted so they owner had hit something real hard. So after I had swapped over to a spare cover and checked the cam out for any loose plastic gear and the lobes for the lift. All was good to go, so I thought. I went back into the sump again to check things out again. Still the same, very smooth without the plug installed. Anyway I didn't even think about the key after all that. Usually I will check those but this time I had taken more time than usual...oh well live and learn...maybe I'll put a string on my finger. I was looking at the pushrod on the exhaust side of your engine and I had thought the rod was bent when the compression release kicked in.
I have learned over the years to always pull slowly the first time on a unfamiliar machine because of this issue
I’ve had several GX390 on small machines and the compression release arm was stuck tight
Oil was terrible and metal shavings in it
Keep the oil change folks 😊
Very well said. Agree 100%
Will low octane make it kick back
I suppose if it was warm but that would be very rare if it was possible. These don't have super high compression