Kohler KT17 one cylinder

[edgro 677]

Series 2 KT 17 in 417A. It starts and runs on front hole only. no evidence of combustion showing on the rear plug,

and the plug is not getting wet.

It will start and run with rear plug wire off, does nothing with front plug wire off, not even a fart..

So far I have replaced the coil and plug wires.

I checked the compression today, both cylinders show 60 lbs on my gauge. checked with finger also, both holes feel the same.

Pulled valve covers, found both valves are moving, checked for clearance, found there is none on back valves.

Any thoughts on this?

It seems that if there was at least some compression, you would get at least a little combustion, rather than nothing at all

[pfrederi 18,034]

Do you have a spark plug tester ($5 at harbor Freight)..are you getting spark on the rear.  If the plug wire will reach put the front wire on the back plug and try KTs fire on compression and on exhaust strokes so there is no problem switching wires.

[edgro 677]

yes plenty of spark (hand tested), new coil and wires. front hole will run off either plug wire

[squonk 41,704]

An intake manifold leak to one cyl. could lean things out enough to cause a dead one. 

[oldredrider 2,553]

Since you don't have any valve clearance on the rear cylinder, you probably don't have enough compression for that cylinder to fire. Adjust the valves to spec and see what happens. 

Also, swap plugs. Sometimes they won't fire under compression.

[pfrederi 18,034]

.003-.006 Intake  .011-.014 Exhaust (cold)

valves in KTs are not adjustable like other K series.  if the clearance is too little you have to grind off a bit of the stem...It doesn't take much I got a bit carried away on one of mine an you can hear a tick....

Edited October 8, 2017 by pfrederi

[edgro 677]

I sprayed around intake with carb cleaner with engine running, it didn't pick up any.

The odd thing is that on my old compression gauge, the dead cylinder showed slightly more compression (multiple checks)

Most likely I will pull the head, or other option is, I have a c120 with a broken frame that has a good running, non leaking/non smoking engine for a donor.

 

[edgro 677]

So I pulled the head, used a file and set the valve clearance. Reinstalled head, and it now has 90+ psi compression on the back hole. Now it starts and still runs on only one hole at a time. However, I can run either cylinder off the front coil tower, The back coil tower has spark, but will not fire a cylinder. It is a new gorrilla motors Harley coil. Changing point gap makes no difference. I tried connecting both plug wires to the front coil tower, and that was no start. Is it possible to run 2 separate coils thru one set of points?

Anyway, I next will use my C175, which runs fine, and do some swapnostics.

I think I already did this once, but that was before the one hole valve job. Also don't know if I tried switching spark plugs leads after installing the new coil because it was always the back that wouldn't fire. Now it's one or the other, but not both at the same time.

[953 nut 56,289]

3 hours ago, edgro said:

Is it possible to run 2 separate coils thru one set of points?

I think that is pretty much what you are doing with the stock coil. Will the store take the Harley coil back and replace it?

[ericj 1,578]

I think I heard that not all Harley coils fire both at the same time, could this be possibly your problem ? just asking since you are having problem

 

 

 

eric j

[edgro 677]

So I took the coil off my c120, wired it in line with the gorilla coil, used that coil to run the other cylinder, and lo and behold it started and ran on 2 cylinders.  Apparently the gorilla coil is more like a monkey. Bought it a couple years back, so most likely will run 2 separate coils or get a Delco coil w/ two towers.

Thanks for all help and advice

[edgro 677]

Got it running on both cylinders now. Here are some pics of GM coil install.

I made a bracket to mount the new coil, condenser, and resistor to the original coil mounting location.

I made an insulator out of 1/4 plastic for between the bottom of the coil and the bracket

[953 nut 56,289]

1 hour ago, edgro said:

running on both cylinders now.

       What was the GM coil used on as original equipment?  

[edgro 677]

I got one that fit my car, just in case it didn't work on the tractor.

2003 Chevy Venture. They can be had for around $25 or so.

[953 nut 56,289]

3 hours ago, edgro said:

I got one that fit my car, just in case it didn't work on the tractor.

2003 Chevy Venture. They can be had for around $25 or so.

   I never would have given a late model coil pack a thought. I know that they are operated by a "Trigger" on the crank shaft and had no idea they could be hooked up to a set of points.  Great information!       

[oldredrider 2,553]

Gonna have to file this in my "must remember" brain. Great idea. And comparatively inexpensive too. Thanks. 

[953 nut 56,289]

Hope @Sparky  Sparky-(Admin) or one of the other moderators can move this (post 12 & 14) to the instructional area for us. Great information and needs to be made easy to find again.

http://www.wheelhorseforum.com/forum/142-instructional-threads-and-videos/

[edgro 677]

I actually found this repair idea at:

 

gardentractorpullingtips.com/ignition.htm

 

lots of good ignition related information there

 

also noted this page said to use two coil resistors, so I got one that had two resistors in one,

but it would not fire when connected thru both of them.

So it's connected to the one resistor, we will see how this works like this in the long run

[pacer 3,174]

Along these lines - JFWIW (just for what its worth) Some years back my D180 coil cracked open and being $broke (new then was around $200) I had several auto type coils and I rigged up 2 of them on the twin -- and, it worked -- but, not 100%. I ran it for a couple yrs this way until I could afford a REAL coil. I think I had forgotten how well the big twin would run and perform cause once I put the new coil on --- whoa!! quite a difference!

[edgro 677]

As an update to this I finally took time to work on it before this winter.

With the car coil, it had a weak spark, and was hard if not impossible to start in the cold weather, bad for snowblower tractor.

Bypassing the resistor made it start, but it ran bad, lots of popping and misfiring

Found 2 cylinder Kohler coil kits can now be had from ebay for around $30, so this was installed. 

Tractor starts and runs good now.

We will see what happens this winter

[pacer 3,174]

30 minutes ago, edgro said:

ran bad, lots of popping and misfiring

 

That pretty well describes my experience with the 2 auto coils. Would run without resistors but really poorly, with resistors ran ----- OK?? and back firing -- whoa!! til it warmed up, As mentioned when I finally got the proper coil it ran sooooo much more nicely!

[edgro 677]

agreed. it was very strange how this ran with no resistor.

almost would have thought it was a fuel problem.

I guess that shows how much ignition affects your overall performance.

the last tractor I bought ran crappy, and a new condenser fixed it