troutbum70 858 #1 Posted February 24, 2020 Picked up a new leak down tester at harbor freight yesterday. Done first test on cold engine then next two after a good warm up. The one at a little over 50 psi cold, then after warm up 60 psi first and 70 last. Had small leakage at heard coming out fill tube and small leakage coming out carb, thinking that might be improved with a valve adjustment. What I did find also is the butterfly on throttle shaft is only opening about a 1/4 of the way. So that is not good. 1 Share this post Link to post Share on other sites
ebinmaine 72,707 #2 Posted February 24, 2020 29 minutes ago, troutbum63 said: What I did find also is the butterfly on throttle shaft is only opening about a 1/4 of the way. So that is not good That's enough to have a good running engine but as you likely know it should open more. Best not to run that til you figure out why it's doing that. Could be a loose butterfly screw and you don't want that in the engine. Share this post Link to post Share on other sites
troutbum70 858 #3 Posted February 24, 2020 I think it is because the throttle shaft and lever are so badly worn. Share this post Link to post Share on other sites
ebinmaine 72,707 #4 Posted February 24, 2020 Just now, troutbum63 said: I think it is because the throttle shaft and lever are so badly worn. That might be it. Share this post Link to post Share on other sites
troutbum70 858 #5 Posted February 25, 2020 More interested in what others with way more experience than I think about the numbers I got on leak down test. Carb needs rebuilt for sure. Watched your YouTube video of your wife out there hammering on the snow, my wife wants no part of that she hates the cold. 2 Share this post Link to post Share on other sites
ebinmaine 72,707 #6 Posted February 25, 2020 2 minutes ago, troutbum63 said: Watched your YouTube video of your wife out there hammering on the snow, my wife wants no part of that she hates the cold Trina doesn't love the cold either.... She DOES love Wheelhorse seat time though. Share this post Link to post Share on other sites
Cvans 1,009 #7 Posted February 25, 2020 I have never done a leak down test. Always went by the compression test. Be interesting to see what you come up with. Do you use a timed test? Share this post Link to post Share on other sites
troutbum70 858 #8 Posted February 25, 2020 Eric my wife is afraid of the tractors because most of our property is side hill. Cvans a timed test would only change the values if the air supply dropped below the value preset on the supply gauge. I was hoping the two numbers to be a little closer. 1 Share this post Link to post Share on other sites
ebinmaine 72,707 #9 Posted February 25, 2020 1 minute ago, troutbum63 said: Eric my wife is afraid of the tractors because most of our property is side hill We live on a mountainside. ALL of our property is an incline of some sort except the driveway. It just takes a bit of getting used to. Trina's a country girl and been a gear head her whole existence. 1 1 Share this post Link to post Share on other sites
troutbum70 858 #10 Posted February 25, 2020 My wife grew up in the flat land, but she has lived here on this side hill for the last 47 plus years. Taught her to drive the semi which she did for 13 years with me back and across the US, but no desire to ride a tractor on the side hill hi hi. 2 Share this post Link to post Share on other sites
squonk 43,843 #11 Posted February 26, 2020 The biggest thing with the leak down test is to make sure the engine is at TDC. When putting air into the cylinder it is real easy for the air to move the piston. I like to mark the flywheel at TDC and make sure it stays there. If it moves a little it will put air thru the carb and throw off your reading 1 Share this post Link to post Share on other sites
953 nut 60,068 #12 Posted February 26, 2020 On an engine with ACR you will want to be a couple degrees past TDC on the compression stroke so the exhaust valve will be closed. Clamping a couple pieces of metal to the flywheel that are in contact with the frame will keep the engine from rolling over. Share this post Link to post Share on other sites
troutbum70 858 #13 Posted February 26, 2020 Thank you guys for the reminder I did in fact forget to make sure it was still on TDC, I was a little surprised that there was little difference between cold engine and hot engine. Out of the 3 test the leakage I could hear was crank case and intake. I am going to run again and make sure fly wheel does not move and I do have both marks marked on fly wheel. Share this post Link to post Share on other sites
troutbum70 858 #14 Posted February 26, 2020 Follow up today on leak down test, made sure it stayed at TDC. First one cold and then engine block around 100 degrees, nut much difference between the two. The leakage sounds equal between intake valve and crank case at fill tube, if any at exhaust I could not hear it over the other two. Is it possible the intake could be improved with valve adustment? Is the loss enough to effect operation of the engine? Top reading is cold engine. Share this post Link to post Share on other sites
lynnmor 7,823 #15 Posted February 26, 2020 Of course the valves should be adjusted correctly, but any clearance should give a valid test. It is normal to have leakage past the rings because they all have a gap, but there should be next to none thru the valves. Check for clearance on the intake valve and if there is some, I would do a valve job. Share this post Link to post Share on other sites
Cvans 1,009 #16 Posted February 27, 2020 If your hearing leakage through the intake then as stated I would check the intake valve clearance and then the face of the valve and the seat. Share this post Link to post Share on other sites
troutbum70 858 #17 Posted February 27, 2020 Tnx all for your thoughts I agree probably going to have the head off and do the valves. Wonder if I will find the intake valve cracked. Share this post Link to post Share on other sites
