KT17 peak torque speed

[JohnD 145]

I started the KT-17 on my C-175 this morning for the first time with the temperature was below 32C.  After warming up for engine for about a minute (at 3/4 throttle), I engaged the hydro static and it dragged the motor down to a stall.  After repeating this cycle another time everything was normal on the third try.  The hydro has a recent oil change, so I know it isn't frozen.  I took it for a quick drive to confirm normal operation. 

 

I engaged the hydro with the KT-17 at about 3/4 throttle.  What's the best throttle position for maximum torque to warm up the hydro?  Or would starting at a slower speed be better for the hydro warming up (if the KT-17 has enough power)?   

 

I'm thinking this KT-17 might be ready for a valve job (or more) next summer. 

[Bill D 1,926]

How long have you owned the tractor?  How many hours on the engine?  Do you have the right oil in it for winter use?  Does it burn oil?  Have you done a compression check on both cylinders?  I have a KT 17 with over 1300 hours on it.  It has 100+ psi on each cylinder.  It doesn't use any oil.

I would recommend new plugs, plug wires, new points and condenser first before tearing into a rebuild.  Set the timing with a timing light.  Rebuild the carb and replace the fuel lines, tank valve (possible clogged fuel strainer) and pump if needed.  Also, run a ground wire from the battery directly to the engine block.  Weak spark can cause all kinds of problems.  Bill

[JoeM 7,874]

like @Bill D said a tune up never hurts.

I would ask this question, if you put on a little choke does that help when you engage the hydro? I have found some of the machines I tested out have to be a little on the rich side carb setting. They run a little crappy no load but are much better when working. Also, I have one machine that is just plan cold blooded. It has to warm up for a good 5 before I do anything. 

[peter lena 8,647]

JOHN D , I  AGREE WITH,  BILL D on the detail search for problem areas , any problem you might have is really increased in colder weather . another very important thing is the , battery grounding , from engine corner mount to battery rail grounding point , found that to really help out , do you have a battery tender ? use it ,  if you find the problem , go back and verify the function of all areas , obvious things will show up , good luck , pete 

[edgro 677]

I have same tractor, i usually leave the transmission engaged when starting. This tractor it takes a minute or so for the hydro to kick in anyway, longer when colder. This seem to work for me. If it is really cold and the trans is disengaged, it will bog down as you described when engaged

[JohnD 145]

14 hours ago, Bill D said:

How long have you owned the tractor?  How many hours on the engine?  Do you have the right oil in it for winter use?  Does it burn oil?  Have you done a compression check on both cylinders?  I have a KT 17 with over 1300 hours on it.  It has 100+ psi on each cylinder.  It doesn't use any oil.

I would recommend new plugs, plug wires, new points and condenser first before tearing into a rebuild.  Set the timing with a timing light.  Rebuild the carb and replace the fuel lines, tank valve (possible clogged fuel strainer) and pump if needed.  Also, run a ground wire from the battery directly to the engine block.  Weak spark can cause all kinds of problems.  Bill

I've only had the tractor since, September, so I'm not sure how many hours are on the engine. 

 

I just swapped it to 10W30 in the engine a couple weeks back.  It didn't burn any 30W oil through the fall, I'll keep an eye on it through the winter. 

 

I ran a compression test and only had 75 psi on the front and 77 psi on the rear, but later realized I didn't let the engine warm up before I ran the test, so that's probably inconclusive. 

 

When I changed the plugs, and went back to 0.025" gap instead of the 0.040"+ the PO was running, I noticed the engine has more of a growl when under load than the normal purr.  That's making me think I have a leaky exhaust valve, and thus the talk of a 'partial' rebuild. 

 

How do you adjust the timing on a KT-17? 

 

6 hours ago, JoeM said:

 if you put on a little choke does that help when you engage the hydro?

 

I'll give that a try. 

 

4 hours ago, peter lena said:

 

All the wiring looked pretty good and passed the wiggle test.  I'll take another look and verify the block to battery wiring.  Its probably worth a removal, sandpaper, dielectric grease and reconnect just to be sure. 

 

Thanks all!  (edgro too!)

 

[JohnD 145]

Tonight I let it warm up at 3/4 throttle for 3 minutes and then it engages the hydro with no issues.  If I take it to full throttle while the hydro is warming up the hydro whines, so 3/4 looks like the magic setting. 

 

Here's a photo at 2 minutes of warm up with a nice blue haze in the shed, so it is burning some 10W30 while warming up.  Next time I have it out I'll let it idle in the shed and see if it looks the same after it is warmed up.  

 

 

[Bill D 1,926]

The compression seems low.  Was the throttle wide open when you were checking the compression?  Throttle position makes a big difference.  Check the engine manual for timing instructions.  Adjusting points gap sets the timing.  Be sure to reinstall the screws for the points cover when adjusting.  One screw is tapped into a pressurized oil passage.  Follow the procedure in the service manual for using a timing light to set the timing.  Bill

[JohnD 145]

18 hours ago, Bill D said:

Was the throttle wide open when you were checking the compression?  Throttle position makes a big difference.

Thanks, that's good to know.  It was closed when i ran this test, so that's another factor throwing off my previous results. 

[Bill D 1,926]

Garry @gwest_ca should have a manual for this engine.  They can also be downloaded from the Kohler website as well. Do you have a series 1 or series 2 engine?  Bill

Edited December 10, 2020 by Bill D

[JohnD 145]

I have a Series I (#24233), and I have the manual.  A lot of this will probably make more sense after I try and do it the first time!