c175inMA 8 #1 Posted April 4, 2013 Hi everyone i finished a rebuild on a kohler K341 which ran before it was rebuilt and now it won't start. It doesn't even want to crank over a full speed unless the spark-plug is out. It almost seems like it has too much compression. The starter, battery and solenoid are good. When the engine cranks it blows a cloud of gas out the carburetor and spins backwards.Then with a little coaxing it will turn completely over and start the process over again. I have spark, and the battery is grounded directly to the block, so I don't think it's the starter or the ignition system. Any ideas? Thanks in advance, Paul Share this post Link to post Share on other sites
mike67 33 #2 Posted April 4, 2013 Sounds like it's getting too much gas- almost to the point of hydraulic lock. See how it spins with no fuel going in. Share this post Link to post Share on other sites
groundhog47 347 #3 Posted April 4, 2013 (edited) Did you verify electrical timing and mechanical timing. Did you torque the flywheel, if not a "back surge" may have sheared key, leaving a visible no spark and timing mark mismatch (oops magneto only). Was ACR working before and appear working now. Guess who had all these probs except for ACR and mech timing. Kohler I know is this one but had a Tecumseh that compression release disappeared and sheared flywheel starter ring . Edited April 4, 2013 by groundhog47 Share this post Link to post Share on other sites
c175inMA 8 #4 Posted April 4, 2013 it did the same thing minus the cloud of gas out the carb when i tried it dry. The ACR appears to be working correctly. I'm pretty sure i torqued the flywheel down to specs. Share this post Link to post Share on other sites
520HC 207 #5 Posted April 4, 2013 Sounds like timing is off. Share this post Link to post Share on other sites
855ownerJoel 32 #6 Posted April 5, 2013 I agree, sounds like timing is off. Opening valves when shouldn't ? And not opening when they should. Share this post Link to post Share on other sites
WH854 44 #7 Posted April 5, 2013 Take head of put piston at TDC the valves should both be closed. Right? Share this post Link to post Share on other sites
Callen 64 #8 Posted April 5, 2013 Check your point gap. Another new plug, then next would be check the valve lash Share this post Link to post Share on other sites
c175inMA 8 #9 Posted April 6, 2013 Thanks for the replies I tried a plug i know works. I took off the head and valves seem to be working properly. I have already adjusted the valves. Points i adjusted multiple times according to the manual. Both valves are definitely closed at TDC. Any other ideas? Share this post Link to post Share on other sites
Rock farmer 41 #10 Posted April 7, 2013 Paul, How did you test your spark? The engine could just be tight from the rebuild. But a weak battery would also cause weak spark and slow cranking. I would test timing by grounding the spark plug and putting my thumb over the spark plug hole. Your thumb will feel the compression when you see the spark. It's not much of a test, but,if you don't see that happening. It tells you something! Joe Share this post Link to post Share on other sites
puddlejumper 67 #11 Posted April 7, 2013 when you took the head back off was the exhaust valve opening slightly before TDC to indicate compression release was working? Share this post Link to post Share on other sites
c175inMA 8 #12 Posted April 7, 2013 I will try the thumb over hole test. Yes the ACR seemed to be working Share this post Link to post Share on other sites
Callen 64 #13 Posted April 7, 2013 Check your carb settings? Share this post Link to post Share on other sites
WH854 44 #14 Posted April 7, 2013 . When the engine cranks it blows a cloud of gas out the carburetor and spins backwards.Then with a little coaxing it will turn completely over and start the process over again. Any ideas? Thanks in advance, Paul Could be the crankcase vent is plugged or not working. Check it out Chas Share this post Link to post Share on other sites
rmaynard 14,805 #15 Posted April 7, 2013 Back to basics. What kind of "rebuild" did you do? What was done and what was replaced? 1 Share this post Link to post Share on other sites
c175inMA 8 #16 Posted April 8, 2013 i tried the thumb over hole trick and the compression and spark are coming at the same time. The rebuilt was new connecting rod, cylinder, gaskets everywhere, removed balance gears, cylinder walls were honed (still well within specs so no overbore), and the valve seats were ground. I will try starting the engine with the oil fill loose to see if it's the atmospheric vent. Thanks again for the responses Share this post Link to post Share on other sites
MalMac 1,328 #17 Posted April 8, 2013 Did you torque the rod to correct spec. Not over tighten. The book gives in/lbs and has to be converted over to ft/lbs if your using a ft/lbs torque wrench. I had a friend over tighten a rod on a rebuild and could not get it to turn over. Acted just like a weak battery or starter. Share this post Link to post Share on other sites
c175inMA 8 #18 Posted April 8, 2013 I am pretty sure i converted the torques. I definitely didn't just torque the bolts to the in-lb specs except with foot pounds. The engine cranks fine with the sparkplug removed Share this post Link to post Share on other sites
puddlejumper 67 #19 Posted April 9, 2013 I think maybe you have a weak battery or starter, I have a 12 horse in a cub that did that once and a new starter fixed it. And since this is a new rebuild the engine should be tight and the old starter just cant handle it. 2 Share this post Link to post Share on other sites
Rock farmer 41 #20 Posted April 9, 2013 I think maybe you have a weak battery or starter, I have a 12 horse in a cub that did that once and a new starter fixed it. And since this is a new rebuild the engine should be tight and the old starter just cant handle it. I was thinking the same thing! If not that than bad wire connections. Sometimes you can dis-assemble the starter and clean it. If the brushs aren't too worn it may do the trick! Joe Share this post Link to post Share on other sites
c175inMA 8 #21 Posted April 12, 2013 Well i got it running It took a lot of exhaust valve adjustment, ignition adjustment, and cranking but it finally fired up. Thank you guy for all your help. I had to adjust the exhaust valve down to like .008" to get it to crank properly but it works. 1 Share this post Link to post Share on other sites
oldredrider 2,547 #22 Posted April 12, 2013 Since you had to adjust the exhaust valve so tight, you probably have a worn ACR tab on the cam. That is certain to give you starting problems as the valve won't open enough on start up. I've had to carefully bend the tab to compensate for wear. Share this post Link to post Share on other sites
c175inMA 8 #23 Posted October 15, 2019 For closure on this thread: while I was able to get the engine to start 6 years ago, it was almost impossibly hard to start.I had to have a fully charged battery and a jumper pack, and even then it labored to turn over. More recently, when I wanted to get it running to sell it, I put a compression tester on it and found that I was pushing 130psi+ (from memory). So clearly the ACR was not working correctly. I took the oil pan off and found that the spring for the ACR tab was in the wrong place, not pushing the tab where it needs to be. 16 year old me was not careful enough Now it starts with the tappets set to spec. Thank you all for your help on this! 3 3 Share this post Link to post Share on other sites
Tuneup 1,413 #24 Posted October 18, 2019 I and I'm sure the list greatly appreciate your feedback to close thiis, especially considering the time that's gone by. 1 Share this post Link to post Share on other sites
ebinmaine 62,374 #25 Posted January 1, 2023 On 10/18/2019 at 8:26 AM, Tuneup said: I and I'm sure the list greatly appreciate your feedback to close thiis, especially considering the time that's gone by. Agreed. I'm here Jan 1, 2023 looking for information. Found this thread. Great to see a proper followup. Share this post Link to post Share on other sites