K321 14 HP engine kick back when starting

[BOBTHEBOPPER]

I have and old cub 147 hydrostatic tractor with a 14 HP Kohler engine which I rebuilt many years ago with no operation problems. The problem I am having is that lately when starting the engine it tends to kick back. This started about a year ago and was not as prevalent during the warmer weather since it would start. I live in New York state and I have noticed in the late fall this problem started to rear its head. I tried checking the points thinking they gap may have opened slightly however the gap was set at .020 as is required. My next thought was maybe it is the fuel since summer and winter gas has a different formulation. Today March 23 the temp was up near 40 and I tried starting the engine but it would only kick back and not start. When I noticed list last fall I thought about the ignition process. If your points open to early the spark is present way before top dead center of the piston travel and that could cause kick back. I experimented by closing the pints slightly and this seemed to help but not enough to warrant leaving them slightly closed, thus I changed back to the factory required .020 gap. My question is has anyone experienced this problem and if so does anyone have any explanation as to what might be the problem and what steps should I take to correct this problem The engine has been fine for the last 8 years since the last overhaul.
BOBTHEBOPPER

 

[ILENGINE]

Check valve clearances to make sure still in spec. Could also be a problem with the Automatic compression release or ACR. And on those engine the .020 point clearance is considered a starting point and either need to set the exact timing using either a timing light or ohm meter to align the point opening with the timing mark on the flywheel. It starts at .020 but final adjustment can be from .014-.024.

 

[BOBTHEBOPPER]

Check valve clearances to make sure still in spec. Could also be a problem with the Automatic compression release or ACR. And on those engine the .020 point clearance is considered a starting point and either need to set the exact timing using either a timing light or ohm meter to align the point opening with the timing mark on the flywheel. It starts at .020 but final adjustment can be from .014-.024.

ILENGINE thanks for for prompt reply. I retarded the spark and set the point gap to .o15 and the engine started and ran fine. This solved the problem however does anyone have any idea why after 25 years of running this engine with a point gap of .020 it ran fine until last year? A puzzle!

 

[123tim]

I think that I have the same or a similar problem. I have a k301 that ran and started "ok" last summer and seems to act the same way that yours was acting when I try to start it now. I can get it started after a lot of work, but mostly it just chugs and often backfires through the carb when you turn the key to the off position after trying to start it. Changed the carb and this seemed to help a little, but not by much. Never messed with the points and hardly know where they are on this engine, but considering it. I think that maybe I'm noticing it now because of the cold weather. I think that the hotter the engine is the easier it is to start. I was running it last year when the temps were in the 90's and now they're in the 30's at night and 50's in the day. The engine really doesn't have a chance to warm up very much. The engine doesn't restart very well now even after running and warming up however.

 

[BOBTHEBOPPER]

I think that I have the same or a similar problem. I have a k301 that ran and started "ok" last summer and seems to act the same way that yours was acting when I try to start it now. I can get it started after a lot of work, but mostly it just chugs and often backfires through the carb when you turn the key to the off position after trying to start it. Changed the carb and this seemed to help a little, but not by much. Never messed with the points and hardly know where they are on this engine, but considering it. I think that maybe I'm noticing it now because of the cold weather. I think that the hotter the engine is the easier it is to start. I was running it last year when the temps were in the 90's and now they're in the 30's at night and 50's in the day. The engine really doesn't have a chance to warm up very much. The engine doesn't restart very well now even after running and warming up however.

Newbie, As you probably read my problem if yours is similar (kick backs) and hard to or not able to start then look at the points. If it is kicking back when trying to start you may have a valve problem however please check the points. They are under a cover on the left side of the engine just below the carb towards the front. Remove the cover and rotate the crank by hand and see when the points are fully open. Check with a flat feeler guage to see what the point opening measures. If it is over ,020 gap then prehaps this is your problem. Point gaps will widen with age. If so try my solution, I set my gap at .015 but maybe I could have set them slightly wider but it solved my problem. Let me know, good luck.

BOBTHEBOPPER

 

[Compact7]

Good info, Thanks! My 1967 Sears Compact 7 with a transplanted 2hp B&S out of a Cooper rotary mower had a nasty kickback.

I had removed the pull start and used a dischargeable B&S Firestorm drill with a big socket to engage the crankshaft to spin the motor to start it. A big kickback broke the handle free of the motor housing. I had to install heavy wire to jury rig that drill.

Now my health sucks, I'm not able to try your tips to fix it! Ratz!!
-Ed

 

[Tiger Small Engine]

ILENGINE thanks for for prompt reply. I retarded the spark and set the point gap to .o15 and the engine started and ran fine. This solved the problem however does anyone have any idea why after 25 years of running this engine with a point gap of .020 it ran fine until last year? A puzzle!

As an engine ages and accumulates hours, tolerances change, parts wear, etc. In other words, the health and condition of the internal engine parts change, and adjustments such as points, valves, and carburetors need to be made to accommodate these differences.

 

[SeniorCitizen]

Not familiar with that engine , but sometimes points will fail by leaving a pit in 1 side with a matching mound on the opposite side .

 

[BOBTHEBOPPER]

Good info, Thanks! My 1967 Sears Compact 7 with a transplanted 2hp B&S out of a Cooper rotary mower had a nasty kickback.

I had removed the pull start and used a dischargeable B&S Firestorm drill with a big socket to engage the crankshaft to spin the motor to start it. A big kickback broke the handle free of the motor housing. I had to install heavy wire to jury rig that drill.

Now my health sucks, I'm not able to try your tips to fix it! Ratz!!
-Ed

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Compact7, Not sure about B&S engines if they are a similar setup as the Kohler series however if you are experiencing heavy kick back on starting it might be the points, See the reply from ILENGINE This is good info.