Eugene wrote:SundaySailor wrote:In that once the muffler starts rattling around it causes a number of other problems including breaking the mounts and letting cold air hit the hot exhaust valve and causing further damage.
Ya all are gonna have to explain how cold air can enter a recently stopped, hot engine and damage the exhaust valve. Ain’t gonna happen.
Rick Prentice wrote:Now I'm wondering if that's what's wrong with my 1250. I can go out and get it started and drive it around alittle. After it warms up it decides to quit and you might as well forget about starting it again.
Typical symptom of a faulty coil.
SundaySailor wrote:That is the classic sign of the burned valve.
Not.
Eugene, with all due respect, etc., you are not quite right this time. If I can, I will try to dig up my burned valve and take a photo of it. It was definitely burned on the side.
Also, I'm still running on the
same coil that this engine was having problems with, and I've run this engine solid for 2 hours moving mulch. If it was the coil, then why did the engine rebuild (which included new valves) cure the problem, and I'm still running on the same coil?
BTW, I did change out the coil in my original troubleshooting and found that wasn't the problem.
Here's what happens with the Quietline engines: There is an elbow coming out from the exhaust port. It isn't all that hefty to start with. Then, it passes through a cast aluminum duct of which there is a very heavy muffler attached to both the duct work and also to the elbow. As I remember correctly, those are the only two attachment places for that heavy muffler.
This series of engines doesn't have the balance gears and also has the ISO rubber mounts. Those mounts wear along with all that other vibration and the muffler loosens up and starts vibrating. The vibration gets worse to the point the entry point on the muffler cracks and in my case it also broke the elbow. This allowed cooler air to enter the hot exhaust area, and little by little caused the valve to burn. At least this is what my machinist said happened.
I've also had plenty of contact with other people who have the Quietline series of Cub Cadet, and they've confirmed they had the same problems - loose muffler, runs for a while, shuts down, no start condition. No amount of carb adjustment would do anything. Pulled the head off, and viola - burned valve.
Now mind you, this all takes place over a long period of time. You also have to keep in mind this line of Cub Cadets has been around since the mid 1970's and the prior owners for the most part just drove them into the ground with little regard to proper maintenance.
Geez, sounds familiar - like with the Farmall Cubs doesn't it?
Anyway, I will try to see if I still have that valve. If so, I'll sure as heck post a photo. It cost me a good penny to get this thing back and running, but I truly enjoy this machine.