KT 17 Series II

[Z-man 0]

B)

My 417 -Auto lacks power and is hard to start ;and runs with some backfiring through the carb and exhaust. I have spark to both cylinders, both have compression. It has back(cylinder) pressure coming up through the carb and some raw fuel. I switched the wires from back to front and vise versa; and it wont run, it will only run with the rear plug wire attached to the rear cylinder, when its switched to the front cylinder it dies.I can only assume the front cylinder is not burning the fuel that's getting to it and that's why its coming back up through the carb.

Maybe it's the external combustion type KT--

did they make one and I'm not aware?

Valve issues??

[nylyon-(Admin) 7,122]

I'm not familiar with the Kohler twins, maybe the valves are adjustable? Look in the links section you can probably grab a manual for it.

[WheelHorse_of_course 99]

Again, no first hand experience but I have heard of valves getting stuck on some engines. Best of luck. B)

[traktorkidd7/30/93 1]

get new plugs and gap them B)

[Z-man 0]

Thanks , a least I seem to be heading the right direction with the valves. I guess it would be the intake stuck closed ?

Looks like I will be dissecting a Twin Lung this week! Better get some !

[Teddy da Bear 11]

Before doing some valve work. I would pour some "sea foam"' through it. (gas tank).

Keep in mind that whatever crud it loosens will likely end up on your plugs.

Change to new plugs after the seafoam. And check out the timing of the motor.

If that does not do the trick....then take the head off and examine the valve condition.

Good luck....keep us posted.

[Z-man 0]

Before doing some valve work. I would pour some "sea foam"' through it. (gas tank).

What' seafoam, do I have to go to the beach to get it? Or NAPA,

is it similar to Marvel Mystery oil or PB Blaster? Those I can shoot right down into the cylinder head and let it soak?

[nylyon-(Admin) 7,122]

Seafoam is an engine / fuel cleaner which you can use in small engines. It's fun to use on your car, especially the smoke show which follows!

The product has worked for me, but I never had anything serious like you're experiencing. Mine has always been, rough running, hunting etc... NAPA should have it, Advanced, maybe even K-Mart?

[traktorkidd7/30/93 1]

take the heads off and crank it over by hand

[big mike 13]

Easiest place to start is to pull one plug at a time,crank it over and see if it is sucking.MMO or Seafoam may loosen a sticky valve.If not then I would pull the heads to see if the valves are operating correctly.Sadly the KTs do not have adjustable tappets,the valve lash is set by grinding the butt end of the valve to spec.

[Z-man 0]

UPDATE:

Loaded the cylinder with PB Blaster before I left this am.

Just got home with some Seafoam in hand, through it in the tank and she's putting along

I'm gonna go cut the grass with C-125 :horseplay: and check on her in a little

while.

I'll load it up with PB before nite and give all a update tomorrow evening when I get

home.

Thanks for all the advice and keep your fingers and toes crossed for me B)

[traktorkidd7/30/93 1]

Brian it looks like thats gonna be a while considering how big your yard is

unless you put a "turbo" on the C-125 B)

[TT-(Moderator) 1,129]

Brian, I'm not saying this is your problem, but here's a picture of a P-218 Onan with an issue:

Carefully count all of the air cleaner base, choke plate, and throttle plate screws and make sure they are all present and accounted for.

For the sake of sanity, I would pull the head and do a visual inspection of the valves - especially since it's the front cylinder and it's much easier to access.

In rare instances, the valve locks can come off and the spring will no longer close the valve.

[bambooheels 0]

regardless of how well you get with the pb AND SEA FOAM I WOULD TAKE THE HEADS OFF AND DO A VISUAL. THESE are very expensive engines. the best in my opinion of the twins made by kohler. new plugs and wires are a must. crank her over without the plugs in her too. i have several parts for these if you need something all used of course but not abused. good luck, keep us posted. B)