M-18 running rough/missing

[ol'George]

John,
The Cams that break are caused by a rod breaking them, not on their own.
You can try the other carb, why not? you have done most everything else.
When you done the initial compression check and it was good, I didn't think it was valves but I'm always open to learning.
Is the carb on it now, the adjustable kind?
The one from the KT should be adjustable.
Try it,you might get lucky there and adjust it so it runs fine.
As far as right/left side,it is almost always viewed from the operator position.
Did you check the intake manifold for an obstruction on the R side like a dead mouse or stuff?
At this point we all are grasping @ straws.
And yes, do run another compression test just for a base line.
If the carb swap produces no joy, then remove the muffler and try running it.
somewhere we all are missing something.
Those things run sweet.
Do not give up!!!!!!!

[john hall]

Carb on it is non-adjustable. I THOUGHT I cleaned it well when I rebuilt it?? Likewise, I think I checked the intake for an obstruction. I'll certainly start with basic checks like fire and compression and progress slowly and methodically. I love the M20 in my 2072, hope to get this one to run just as well.

[john hall]

Well, to cut to the chase--it was the carb all along. After checking the basics--fire, compression--we pulled the fixed jet carb back off and pulled it apart. Can't see anything wrong, didn't notice anything modified, just doesn't make sense. I had 2 KT engines--series 1 and 2. The series 1 had a fixed jet on it, but it had been left out in the rain--I think I can salvage the screw and clamp for the choke cable, that's about it. The series 2 had an adjustable jet carb. I pulled it off and started cleaning it out--had been sitting with fuel in it for several years, began to turn to tar. Took it apart, cleaned it out, used over all the gaskets---because I did not have a kit. Put it on and dang thing fired up. Opened the main about 3/4 and closed the idle jet a pinch--runs fantastic.

I'm some where between relieved, happy and disgusted. Relieved because I'm tired of working on this one, happy because it runs well, disgusted that I didn't give this a try before opening up the engine. Now given the hours on the tach (1700---I really don't think there is that many on the machine or the engine), I'm not upset we put in pistons and ground the valves. Valves had wear as well as the pistons were showing wear also. I do have an oil line leaking I need to address as well as torqueing the heads again. Maybe there is a light at the end of the tunnel after all.

[ol'George]

Originally Posted by john hall

Well, to cut to the chase--it was the carb all along. After checking the basics--fire, compression--we pulled the fixed jet carb back off and pulled it apart. Can't see anything wrong, didn't notice anything modified, just doesn't make sense. I had 2 KT engines--series 1 and 2. The series 1 had a fixed jet on it, but it had been left out in the rain--I think I can salvage the screw and clamp for the choke cable, that's about it. The series 2 had an adjustable jet carb. I pulled it off and started cleaning it out--had been sitting with fuel in it for several years, began to turn to tar. Took it apart, cleaned it out, used over all the gaskets---because I did not have a kit. Put it on and dang thing fired up. Opened the main about 3/4 and closed the idle jet a pinch--runs fantastic.

I'm some where between relieved, happy and disgusted. Relieved because I'm tired of working on this one, happy because it runs well, disgusted that I didn't give this a try before opening up the engine. Now given the hours on the tach (1700---I really don't think there is that many on the machine or the engine), I'm not upset we put in pistons and ground the valves. Valves had wear as well as the pistons were showing wear also. I do have an oil line leaking I need to address as well as torqueing the heads again. Maybe there is a light at the end of the tunnel after all.

There you go, KISS -----keep it simple.
Great news and
Congratulations
You have a good engine you know has new rings,pistons & a valve job.
You learned a lot.
That is worth the time and $$ you spent.
Some paint pictures, some carve wood, still others play sports, all give satisfaction just in different ways.
There is nothing that gives me more satisfaction, than fixing that which malfunctions.
I cut grass today with an M-18 I built from parts and a converted vertical block.
A heck of a good feeling, and if I have to explain that, they wouldn't understand.

[john hall]

Re-torqued the heads this afternoon, they moved maybe 1/8th of a turn. FWIW, you can do it with the engine in the frame and without warping the shields over the heads--we left the bottom bolts in them. It took a little effort to get on the #9 bolt (torque sequence), but I managed and the covers didn't get screwed up in the process. Ran the Cadet for about 30 minutes, drove it 1/2 mile.

[zippy1]

Good the hear you got it going John. Sorry you had to go through all that extra work to get the end results though. I feel your pain...
Just put the engine back in my 1811 after going through it replacing gaskets and seals.Went to start it, "CLICK,CLICK", oh, duh, forgot that the starter was bad, and was going to replace it when I had the engine out.
SO, had to take it back out, and ordered a new one, now I'm back where I started, with a 1811 with no engine in it.

[Oak]

I'm glad it is running well John and this was a great thread. I like the Mag engines so I learned a good bit of info on your adventure. What's next?